JP7694936B2 - Impact Analysis Device - Google Patents

Description

The present invention relates to a striking analysis device, and in particular to a striking analysis device that analyzes the striking of a striking device.

Conventionally, an impact device strikes an object with a design value of, for example, 1800 to 3000 vpm. With continued use of such an impact device, the number of strikes may fall below the design value due to wear of the components, etc., and if this falls, repairs or the like are required to ensure that the device performs as intended.
For this reason, it is necessary to analyze whether the striking device is performing a proper striking operation.

As a device for determining the impact of such an impact device, an impact force determination device has been proposed in which the hydraulic pressure generated each time the breaker strikes is stored in an accumulator via a check valve, and the impact force of the breaker is determined by measuring the pressure when the accumulated hydraulic pressure is saturated (see Patent Document 1).

JP 2015-001419 A

Incidentally, the impact device continuously impacts the target object.
However, while the impact force determination device of Patent Document 1 can determine the impact force of a breaker at a certain point in time by measuring the pressure when the accumulated hydraulic pressure is saturated, it cannot analyze continuous impacts in an impact device that performs continuous impacts.

The present invention aims to provide an impact analysis device that is capable of analyzing successive impacts in an impact device.

(1) An impact analysis device for analyzing an impact of an impact device, comprising:
a measurement value acquiring means for acquiring a measurement value that varies due to impact by the impact device at a predetermined interval;
a time series data generating means for generating time series data showing, as a waveform, a time series fluctuation of the plurality of measurement values continuously acquired at the predetermined intervals;
and an amplitude spectrum generating means for generating an amplitude spectrum indicating a cumulative value of amplitude for each frequency based on the time series data.

According to the configuration (1) of the impact analysis device of the present invention, the impact analysis device includes a measurement value acquisition means, a time-series data generation means, and an amplitude spectrum generation means, and analyzes the impact of the impact device.
The measurement value acquiring means acquires, at predetermined intervals, a measurement value that varies due to striking by the striking device.
The time-series data generating means generates time-series data that indicates, in the form of a waveform, a time-series fluctuation of a plurality of measurement values that are continuously acquired at a predetermined interval.
The amplitude spectrum generating means generates an amplitude spectrum indicating an accumulated value of the amplitude for each frequency based on the time series data.

In this way, measurement values that vary due to the impact of the impact device (for example, pressure values due to impact, measured values of impact force, etc.) are obtained at a predetermined interval (for example, 5 ms, etc.).
Next, time series data is generated that shows, in the form of a waveform, the fluctuations in the time series of the multiple measurement values that are continuously acquired at a predetermined interval.
Then, based on the time series data represented by this waveform, an amplitude spectrum indicating the cumulative value of the amplitude for each frequency is generated.

When an impact is made with the impact device, vibrations etc. caused by this impact remain in the impact device, and the next impact is made while these vibrations etc. remain, resulting in even more complex vibrations etc. that are reflected in the measured values. For this reason, even if the measured values that fluctuate due to the impact are continuously acquired at a specified interval and the time-series fluctuations are shown as waveforms in time-series data, waves of various amplitudes are measured at various frequencies, and it is difficult to determine which waves have occurred as valid impacts based on the acquired measured values alone.

According to the present invention, an amplitude spectrum showing the cumulative amplitude value for each frequency is generated based on time series data, so that the frequency with the largest cumulative amplitude value becomes clear. The frequency with the largest cumulative amplitude value can be inferred to be an effective impact period. For example, if there is a large difference between the frequency with the largest cumulative amplitude value in a properly maintained impact device and that at the time of measurement, it can be determined that the impact device at the time of measurement is not performing impacts properly.

Therefore, it is possible to provide an impact analysis device that is capable of analyzing successive impacts in an impact device.

(2) The impact analysis device described in (1), in which the time-series data generation means generates the time-series data using a corrected measurement value obtained by subtracting the average value of the measurement values acquired by the measurement value acquisition means from the measurement values.

This makes it possible to show measurement values in time series data as positive values (values greater than the average value) and negative values (values smaller than the average value), making it easier to analyze changes in measurement values as waveforms.

(3) The impact analysis device according to (1) or (2) further includes an effective impact number calculation means for calculating the effective number of impacts of the impact device per predetermined time by multiplying the frequency with the highest cumulative value by a predetermined value.

By comparing the effective number of impacts calculated from the frequency with the highest cumulative value in the amplitude spectrum with, for example, the designed number of impacts (for example, the number of pressure fluctuations in the case of an impact device driven by pressure fluctuations in a fluid), it is possible to determine whether the appropriate number of impacts is being maintained in the impact device at the time of measurement.

(4) a storage means for storing the amplitude spectrum generated by the amplitude spectrum generating means;
a display control means for controlling display of the amplitude spectrum generated by the amplitude spectrum generating means on a display means,
the storage means stores a plurality of the amplitude spectra generated at different times,
The impact analysis device according to any one of (1) to (3), wherein the display control means performs control to display the plurality of amplitude spectra generated at different times in an overlapping manner.

In this way, by displaying multiple amplitude spectra generated at different times in an overlapping manner, for example, by displaying an amplitude spectrum immediately after maintenance and an amplitude spectrum after a specified inspection period (e.g., one year later) in an overlapping manner, the changes in the cumulative amplitude value at the overall frequency can be confirmed at a glance. This makes it easier to analyze continuous impacts in the impact device.

The present invention provides an impact analysis device that can analyze successive impacts in an impact device.

FIG. 2 is a diagram illustrating a state in which an impact analysis device according to an embodiment of the present invention is attached to an impact device. FIG. 1 is a diagram illustrating a functional configuration of an impact analysis device 1 according to an embodiment of the present invention. FIG. 11 is a diagram showing a flow of a impact analysis process executed by a impact analysis device according to an embodiment of the present invention. FIG. 13 is a diagram showing an example of displaying time-series data according to an embodiment of the present invention. FIG. 13 is a diagram showing an example of displaying an amplitude spectrum according to the embodiment of the present invention. FIG. 13 is a diagram illustrating a state in which an impact analysis device according to a modified embodiment of the present invention is attached to an impact device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals, and the description thereof will be omitted or simplified.
FIG. 1 is a diagram illustrating a state in which an impact analysis device according to an embodiment of the present invention is attached to an impact device.

(Overall composition)
The impact analysis device 1 includes a detection unit 5 that detects the impact of the impact device 100, a control unit 10 that analyzes the impact of the impact device 100, and a display means 20 that displays the analysis results of the control unit 10, and analyzes the impact of the impact device 100.

Here, the impact device 100 usually repeats impacts at 1800 to 3000 vpm, and when the impact force is measured, it is not always constant, but increases and decreases repeatedly. However, the increase and decrease in the impact force occurs periodically, and a regularity is recognized.
The impact analysis device 1 acquires measurement values that fluctuate due to impact with the impact device 100, and based on these measurement values, analyzes the tendency of the measurement value fluctuations, thereby enabling analysis of the impact of the impact device.

The impact device 100 of this embodiment, for example, continuously impacts a cast product (not shown) set in a frame 110 with the impact section 120 (in the example shown in FIG. 1 , as a piston (not shown) inside the impact device 100 ascends and descends, the piston collides with the impact section 120 as it descends), so that the tip of the impact section 120 continuously applies an impact load to the cast product and removes the core sand of the cast product.
In the example shown in FIG. 1, the detection unit 5 of the impact analysis device 1 is disposed at the position where the cast product is placed (the position where the impact is performed by the impact unit 120).

In the example shown in FIG. 1 , the detection unit 5 includes a cylinder 51 , a piston 52 , a replaceable member 53 , and a detection means 54 .
The cylinder 51 has a non-compressible fluid sealed therein.
The piston 52 is slidably attached to the cylinder 51 and is moved in a slidable direction by the striking portion 120 of the striking device 100 , and transmits pressure generated by striking with the striking portion 120 of the striking device 100 to the inside of the cylinder 51 .
The replaceable member 53 is detachably attached to a portion of the piston 52 that is struck by the striking portion 120, and is directly struck by the striking portion 120. The replaceable member 53 is replaceable when it becomes deformed or worn due to the striking.
The detection means 54 is fluidly connected to the inside of the cylinder 51 and is composed of a pressure sensor that constantly detects the pressure inside the cylinder 51.

With this configuration, when an impact is applied by the impact device 100, the impact section 120 impacts (moves downward) the replaceable member 53 of the detection section 5. The impact force from this impact is transmitted to the piston 52, increasing the pressure of the incompressible fluid inside the cylinder 51. Then, when the piston (not shown) inside the impact device 100 rises and the impact load is no longer applied to the impact section 120, the pressure applied to the piston 52 of the detection section 5 is released, and the pressure of the incompressible fluid inside the cylinder 51 decreases.

The detection means 54 constantly detects the continuous pressure fluctuations of such incompressible fluid during continuous impacts by the impact device 100.

In the example shown in FIG. 1, the detection unit 5 is configured to measure a value that varies due to the impact of the impact device 100 using a pressure sensor, but this is not limited to the above. As long as it is possible to measure a value that varies due to the impact of the impact unit 120 of the impact device 100, any configuration can be used, such as a configuration in which the impact force of the impact device 100 is measured using a load cell (strain gauge) or a configuration in which the state of the part of the impact device 100 that has been impacted is measured using an acceleration sensor.

(Functional configuration)
FIG. 2 is a diagram illustrating the functional configuration of the impact analysis device 1 according to the embodiment of the present invention.
The control unit 10 includes a measurement value acquisition means 11, a time series data generation means 12, an amplitude spectrum generation means 13, an effective impact count calculation means 14, a display control means 15, and a memory means 50, and is connected to the detection means 54 of the detection unit 5 and the display means 20.

The measurement value acquisition means 11 is connected to the detection means 54 of the detection unit 5, and acquires, at a predetermined interval, the measurement value that varies due to the impact of the impact device 100. Specifically, the measurement value acquisition means 11 converts the analog signal value detected by the detection means 54 into a digital signal to acquire the measurement value, and stores it in the storage means 50.

The specified interval for acquiring the measurement values in the measurement value acquiring means 11 may be a preset interval, or an interval set based on the number of impacts set in the impact device 100, and it is desirable for the interval to be equal to or shorter than the impact interval of the impact device 100.
For example, if the impact frequency of the impact device 100 is set to 3000 vpm, it is desirable that the specified interval for acquiring the measurement value in the measurement value acquiring means 11 be 20 ms (1000 ms/50 times) or less, so as to measure at least 50 times per second (3000 vpm/60).

The time series data generating means 12 generates time series data that shows, as a waveform, the time series fluctuations of multiple measured values that are continuously acquired at a predetermined interval. Specifically, the time series data generating means 12 reads out a predetermined number of multiple measured values that are continuously acquired at a predetermined interval and stored in the storage means 50, generates time series data that shows, as a waveform, the time series fluctuations of the read measured values, and stores the data in the storage means 50.

Here, the amplitude spectrum generating means 13 generates an amplitude spectrum based on the time series data generated by the time series data generating means 12 using the well-known fast Fourier transform, so it is desirable that the predetermined number of measurement values read by the time series data generating means 12 be 2 to the power of n (e.g., 256, 512, etc.).

The time series data generating means 12 also generates time series data using corrected measurement values obtained by subtracting the average of the measurement values acquired by the measurement value acquiring means 11 from the measurement values. This makes it possible to remove the DC component of the measurement values acquired by the measurement value acquiring means 11 and analyze the frequency of fluctuations in the continuously acquired measurement values.

The time series data generating means 12 also generates Hanning processed data by multiplying the time series data by a known Hanning function, and stores the data in the storage means 50. This improves the continuity of the waveform, and improves the accuracy of data analysis.

The amplitude spectrum generating means 13 generates an amplitude spectrum indicating the cumulative value of the amplitude for each frequency based on the time series data generated by the time series data generating means 12. Specifically, the amplitude spectrum generating means 13 processes the time series data or the Hanning processed data generated by the time series data generating means 12 using a known fast Fourier transform to generate an amplitude spectrum indicating the cumulative value of the amplitude for each frequency, and stores it in the storage means 50.

The effective hit count calculation means 14 calculates the effective number of hits of the impact device per predetermined time by multiplying the frequency with the highest cumulative amplitude value by a predetermined value. Specifically, the effective hit count calculation means 14 refers to the amplitude spectrum generated by the amplitude spectrum generation means 13, identifies the frequency with the highest cumulative value, and calculates the effective number of hits by multiplying the identified frequency by 60, which is the conversion rate of frequency (Hz) to number of hits (vpm).
For example, when the frequency with the highest cumulative value is 35 Hz, the effective hit count calculation means 14 calculates the effective hit count to be 2100 vpm.

The display control means 15 reads out the time series data generated by the time series data generating means 12, the amplitude spectrum converted by the amplitude spectrum generating means 13, and the effective number of hits calculated by the effective number of hits calculating means 14 from the storage means 50, and controls the display on the display means 20 (e.g., a display, etc.).
The display control means 15 also controls the display of a plurality of amplitude spectra, which are stored in the storage means 50 and converted at different times by the amplitude spectrum generating means 13, in an overlapping manner.

The memory means 50 temporarily stores the measurement values acquired by the measurement value acquisition means 11, stores the time series data generated by the time series data generation means 12, the amplitude spectrum generated by the amplitude spectrum generation means 13, and the effective number of hits calculated by the effective number of hits calculation means 14.
Furthermore, the storage means 50 stores the amplitude spectra generated by the amplitude spectrum generating means 13 at mutually different timings.

The above-mentioned functional configuration of the control unit 10 is merely an example, and one functional block (database and functional processing unit) may be divided, or multiple functional blocks may be combined into one functional block. Each functional processing unit is realized by a computer program executed by a CPU (Central Processing Unit) built into the device, which reads out a computer program (e.g., a core software or an application that causes the CPU to execute the above-mentioned various processes) stored in a storage device (storage means 50) such as a ROM (Read Only Memory), a flash memory, an SSD (Solid State Drive), or a hard disk. That is, each functional processing unit is realized by the computer program reading and writing necessary data such as a table from a database (DB; Data Base) stored in the storage device or a storage area on the memory, and in some cases controlling related hardware (e.g., an input/output device, a display device, a communication interface device). In addition, the database (DB) in the embodiment of the present invention may be a commercial database, but it also means a simple collection of tables and files, and the internal structure of the database itself is not important.

(Processing flow)
3 is a diagram showing a flow of a hitting analysis process executed by a hitting analysis device according to an embodiment of the present invention. In the process flow diagram (flowchart) of FIG. 3, the processing order of each step may be changed as long as the relationship between the input and output of each step is not lost.

In step S1, the measurement acquisition means 11 acquires, at a predetermined interval, a measurement value that varies due to impacts on the impact device 100.

In step S2, the time series data generating means 12 generates time series data in the form of a waveform showing the time series fluctuations of the multiple measurement values continuously acquired at a predetermined interval by the measurement acquisition means 11 in step S1, and stores the data in the storage means 50.

In step S3, the amplitude spectrum generating means 13 generates an amplitude spectrum indicating the cumulative value of the amplitude for each frequency based on the time series data generated by the time series data generating means 12 in step S2, and stores the amplitude spectrum in the storage means 50.

In step S4, the effective impact count calculation means 14 refers to the amplitude spectrum generated by the amplitude spectrum generation means 13 in step S3, and calculates the effective impact count of the impact device per given time by multiplying the frequency with the highest cumulative value by a given value.

In step S5, the display control means 15 reads out from the storage means 50 the time series data generated by the time series data generation means 12 in step S2 and the amplitude spectrum converted by the amplitude spectrum generation means 13 in step S3, and controls the display of the data on the display means 20 (e.g., a display, etc.).

FIG. 4 is a diagram showing an example of displaying time-series data according to an embodiment of the present invention.
In the example of the time series data display, the horizontal axis indicates the number (order) of measurement values continuously acquired at a predetermined interval by the measurement acquisition means 11, and the vertical axis indicates a waveform in which the magnitude of each measurement value is set.

For example, as shown in FIG. 4, the display control means 15 may display time series data and Hanning processed data obtained by multiplying the time series data by a Hanning function in a superimposed manner in which the data is displayed in different ways (e.g., different brightness, color, thickness, line type, etc.).

FIG. 5 is a diagram showing an example of displaying an amplitude spectrum according to an embodiment of the present invention.
In the example of the amplitude spectrum display, the horizontal axis is set to frequency (Hz) and the vertical axis is set to the cumulative value of the amplitude for each frequency, and the graph is shown.

The display control means 15 may, for example, display multiple amplitude spectra converted at different times in a superimposed manner in different ways (e.g., different brightness, color, thickness, line type, etc.) as shown in FIG. 5.

(Modification)
FIG. 6 is a diagram illustrating a state in which an impact analysis device according to a modified embodiment of the present invention is attached to an impact device.

An impact analysis device 1A according to the modified example differs from the impact analysis device 1 according to the present embodiment in the configuration of a detection unit 5A.
The detection unit 5A is a tubular body connected to the impact air circuit for driving the impact section 120 of the impact device 100, and is equipped with a connection part 51A which is filled with impact air and has the same internal pressure as that within the impact air circuit, and a detection means 54.

The detection means 54 constantly detects continuous pressure fluctuations of the striking air during successive strikes by the striking device 100.

The impact unit 120 of the impact device 100 supplies impact air to the inside, causing an internal piston (not shown) to move up and down, and when the piston collides with the impact unit 120 during descent, the tip of the impact unit 120 continuously applies an impact load to the cast product. The area of this piston is different on the ascending side and the descending side, and when equal pressure is generated on both sides by making the area of the ascending side wider, the piston is raised by the difference in thrust. Next, to lower the piston, an internal mechanism stops the supply of impact air to the ascending side at a certain position and exhausts it. As a result, the thrust on the descending side becomes stronger, and the piston descends. When the piston reaches the end of descent (the position where it collides with the impact unit 120), impact air is supplied again, and the piston repeatedly moves up and down.
In other words, when the piston rises, the air for striking flows into the exhausted ascending side, causing a temporary pressure drop with each strike.

The impact analysis device 1A of the modified example makes it possible to analyze such pressure fluctuations and thus analyze continuous impacts in the impact device 100.

In addition, the impact analysis device 1A of the modified example can analyze continuous impacts of the impact device 100 while the impact device 100 is in normal use, so that the impacts of the impact device 100 can be analyzed even in an environment where it is difficult to stop equipment such as a factory line or in an automated environment.

As described above, the impact analysis device 1 according to this embodiment provides the following advantageous effects.
The impact analysis device 1 acquires measurement values (eg, pressure values due to impacts, measured values of impact force, etc.) that vary due to impacts by the impact device 100 at predetermined intervals (eg, 5 ms, etc.).
Next, time series data is generated that shows, in the form of a waveform, the fluctuations in the time series of the multiple measurement values that are continuously acquired at a predetermined interval.
Then, based on the time series data represented by this waveform, an amplitude spectrum indicating the cumulative value of the amplitude for each frequency is generated.
This generates an amplitude spectrum showing the cumulative amplitude value for each frequency based on the time series data, making it clear which frequency has the largest cumulative amplitude value. The frequency with the largest cumulative amplitude value can be inferred to be an effective impact period. For example, if there is a large difference between the frequency with the largest cumulative amplitude value for an impact device 100 in a properly maintained state and that at the time of measurement, it can be determined that the impact device 100 at the time of measurement is not performing impacts properly.
Therefore, it is possible to provide an impact analysis device capable of analyzing successive impacts in the impact device 100.

In addition, according to the impact analysis device 1, the time series data generation means 12 generates time series data using corrected measurement values obtained by subtracting the average value of the measurement values acquired by the measurement value acquisition means 11 from the measurement values. This makes it possible to show the measurement values in the time series data as positive values (values greater than the average value) and negative values (values smaller than the average value), making it easier to analyze changes in the measurement values as waveforms.

In addition, with the impact analysis device 1, by comparing the effective impact count calculated from the frequency with the highest cumulative value in the amplitude spectrum with, for example, the designed impact count (for example, in the case of an impact device 100 driven by pressure fluctuations of a fluid, the pressure fluctuation count, etc.), it is possible to determine whether the appropriate impact count is being maintained in the impact device 100 at the time of measurement.

In addition, the impact analysis device 1 displays multiple amplitude spectra generated at different times in an overlapping manner, for example, by overlapping an amplitude spectrum immediately after maintenance with an amplitude spectrum after a specified inspection period (e.g., one year later), and the changes in the cumulative amplitude value at the overall frequency can be checked at a glance. This makes it easy to analyze continuous impacts in the impact device 100.

The present invention is not limited to the above-described embodiment, and any modifications or improvements that can achieve the object of the present invention are included in the present invention.

Reference Signs List 1, 1A Impact Analysis Device 5, 5A Detection Unit 10 Control Unit 11 Measurement Value Acquisition Means 12 Time Series Data Generation Means 13 Amplitude Spectrum Generation Means 14 Effective Impact Number Calculation Means 15 Display Control Means 20 Display Means 50 Storage Means 51 Cylinder 51A Connection Part 52 Piston 53 Replaceable Member 54 Detection Means 100 Impact Device 110 Frame 120 Impact Unit

Claims (3)

An impact analysis device that continuously applies an impact load to a casting product by an impact part and analyzes the impact of an impact device that removes core sand from the casting product,
a measurement value acquiring means for acquiring a measurement value that varies due to successive strikes by the striking device at a predetermined interval corresponding to the number of strikes by the striking device;
a time series data generating means for generating time series data showing, as a waveform, a time series fluctuation of the plurality of measurement values continuously acquired at the predetermined intervals;
an amplitude spectrum generating means for generating an amplitude spectrum indicating an accumulated value of the amplitude for each frequency based on the time series data;
an effective impact number calculation means for multiplying the frequency having the highest accumulated value by a conversion rate to the number of impacts to calculate an effective number of impacts per predetermined time of the impact device . The impact analysis device according to claim 1, wherein the time series data generating means generates the time series data using a corrected measurement value obtained by subtracting the average value of the measurement values acquired by the measurement value acquiring means from the measurement values. a storage means for storing the amplitude spectrum generated by the amplitude spectrum generating means;
a display control means for controlling display of the amplitude spectrum generated by the amplitude spectrum generating means on a display means,
the storage means stores a plurality of the amplitude spectra generated at different times,
The impact analysis device according to claim 1 or 2 , wherein the display control means performs control to display the plurality of amplitude spectra generated at different times in an overlapping manner.