JPS6078326A - Impact measuring device - Google Patents

Abstract

PURPOSE:To measure quickly a maximum acceleration, acting time, and a velocity variance in conformity with JIS and similar standards by storing the waveform of an impact pulse in an RAM. CONSTITUTION:The impact pulse detected by an acceleration detector 1 is converted by an A/D converter 4. The output of this converter 4 is compared with a trigger level value T by a comparator 12. When the output of the converter 4 does not exceed the level value T, the output of the converter 4 is written cyclically in the prescribed area of an RAM10. When it exceeds the level value T, the output corresponding to a prescribed number of words is written furthermore hereafter. Then, the waveform of the impact pulse to be measured is stored in an area of the RAM10. A CPU5 executes a prescribed operation on a basis of contents of the RAM10. Thus, the maximum acceleration, the acting time, and the velocity variance of the impact pulse are measured quickly in conformity with JIS and similar standards.

Description

[Detailed Description of the Invention] [Technical Field] The present invention is a method of measuring the maximum acceleration, duration of action, and velocity change of a shock pulse when applying it to a specimen in a shock test of electronic components, etc. This invention relates to a covering impact measuring device.

[Prior art]

J■S C5026 stipulates impact testing methods for electronic components. According to the standard, the test equipment shall be capable of generating a shock pulse that approximates the time versus acceleration wear curve of a predetermined ideal shock pulse waveform, and the actual pulse (actually measured acceleration pulse) is based on the ideal shock pulse waveform. It is sufficient that the amount is within a predetermined tolerance range.

Of course, Figure 1 shows the permissible range of actually measured acceleration pulses stipulated in the standard (the standard specifies two types of pulse waveforms to be applied to the specimen, sine waves and sawtooth waves, but here, (The explanation of the sawtooth wave is omitted.)

The ideal half-sine acceleration pulse is as shown by the dotted line in FIG. The measured acceleration pulse only needs to fall within the limits shown by the solid line, and the actual impact velocity change only needs to be within ±10% of the ideal speed change.

The tolerances for acceleration pulses with an action time shorter than 3 nlS are as follows:

The actual pulse size is within ±20% of the ideal pulse size, and the action time is within ±20% of the ideal pulse action time.
It is sufficient if it is within 15%. However, the action time Dm of the actually measured pulse is based on the following equation.

Dm=D(0,1A)10.94・(1) Here, D(
0,1A> is the time between two points where the acceleration is 0.1A in the actually measured waveform.

Well, Iζ, the integral to calculate the speed change is 0 of the pulse waveform.
．． Perform from before 4D to after 0.1D.

Any measured acceleration pulse that falls between the boundaries of the solid line is considered to be a nominal half-sine pulse with a nominal maximum acceleration A and a nominal action time.

Further, the velocity change V of the measured pulse is returned as follows.

\/-Vi ±10% Note that the reference line is required to have no difference of more than ±0.05Δ from zero acceleration.

Now, since JIS C5026 stipulates as above), when conducting an impact test based on the same standard, conventionally, the impact waveform detected by an acceleration detector is amplified by an amplifier, and then The maximum acceleration, action time, and speed change of the measured pulses were determined by displaying or recording them using a cathode ray tube oscilloscope or electromagnetic oscilloscope to ensure that the measured pulses complied with the standards. However, in such conventional methods, it is necessary to spend a considerable amount of time observing waveforms and calculating the three quantities of the maximum acceleration, action time, and velocity change from the recorded waveform force. There were drawbacks.

1 = Conventionally, there have been measurement devices that automatically measure the action time of a shock pulse, but these conventional t1 measurement devices have been used to measure the acceleration waveform of a shock pulse at the baseline (zero point) or This is a simple method in which the duration of the impact pulse is defined as the width that crosses a threshold level that has been set in advance, and has the disadvantage that it is not possible to perform impact measurement in accordance with the JIS standard.

[Purpose of the invention]

The present invention has been made to overcome the above-mentioned drawbacks of the prior art, and is capable of automatically and promptly measuring the maximum acceleration, action time, and speed change of an impact pulse in accordance with J[S and similar standards. The purpose is to provide a shock-proof adventure that can be done.

[Summary of the invention]

The attack measurement device according to the present invention includes an acceleration detector, an A/D converter that converts an analog signal obtained by 4Q based on the output of the acceleration detector, and the A/D converter. 1
trigger level detection means for detecting that the digital value obtained from the output of the converter has reached a predetermined trigger force/level; a memory; and the trigger level detection means detects the trigger force/level. Up to this point, the digital value is written cyclically to each address in a predetermined area of the memory, and when the trigger level detection means detects the trigger level, a predetermined number of words are further written from the point of detection. means for stopping writing of the digital value in the area after the digital value has been inserted into the area; and determining a maximum acceleration of the impact pulse detected by the acceleration detector based on the digital value written in the area; , calculating means for calculating the impact duration of the impact pulse based on the distance between points that are lower than the maximum acceleration by a predetermined level, and calculating the speed change of the impact pulse based on the impact duration. This is what happens.

〔Example〕

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

FIG. 2 shows t! according to the present invention! l! It is a block diagram showing one example of an i-hit measuring device. 1 is an acceleration detector, 2 is an amplifier, 3 is a low-pass filter, and 4 is an A/D converter.

5 is a central processing unit (hereinafter abbreviated as CPU) connected to the microprocessor, 6 is a data bus, 7 is a control bus, and 8 is an address bus.
The output of the /D converter 4 is connected to the data bus 6 via a buffer 11. 9 is a ROM, in which a program executed by the CPU 5 is stored. 10 is a RAM, which has an area for storing rM pulse waveforms.

12 is the trigger level detection means 4j in this embodiment.
It is a comparator with 4 components, which compares the output of the A/D converter 4 with a constant trigger level value T, and when the output of the A/D converter 4 exceeds the lower trigger level value, the trigger force 1 novel detection signal 1] is output. 13 is a counter, and the RA is used to store the shock pulse waveform.
If the total number of edicts in the area of M10 is N, then this is an N-adic counter.

Reference numeral 14 denotes a receiver which selects either the output of the counter 13 or the address signal input from the address bus 8 and inputs it to the address input of the RAM 10.

15 is an I10 port, and a printer 16 is connected to the T10 ports 1-15. 17 is also an I10 port, and an IED display 18 is connected to this I10 port 17.

Next, the operation of this embodiment will be explained with reference to the flowchart shown in FIG. 3 and the measurement example shown in FIG.

The output of the acceleration detector 1 is amplified by an amplifier 2, passes through a low-pass filter 3, and is input to an A/D converter 4. The A/D converter 4 converts the input analog signal into a digital signal at a predetermined sampling period and outputs the digital signal.

On the other hand, after the counter 13 is initialized at the start of measurement,
Count up is performed at the sampling period. Then, through the output number lever 14 of this counter 13, R
It is input to the address input of AMl0. And A/
The output of the D converter 4 is sent to the RAM 10 via the buffer 11 and the data bus 6 while being addressed by the output of the counter 13 without passing through the CPU 5.
DMA transfer is performed.

Here, the CPU 5 does not stop the counter 13 unless the output of the A/D converter 4 exceeds the lower trigger level value as described in (see below). Therefore, since the counter 13 returns to its initial state every N sampling periods, the RA
The output of the A/D converter 4 is cyclically written into the area M10. However, the output of the A/D converter 4 is written from the first address of the area, and when the writing of the N opening is completed, the output of the next A/D converter 4 is written as the above address again. The area is filled in from the first address.

Now, when the acceleration detector 1 detects an impact pulse, the detected pulse passes through the amplifier 2 and the [1-bus filter 3] as described above (by passing through the low-pass filter 3, fine irregularities in the waveform are removed. ), A/'
The signal is input to the D converter 4, and converted into a digital signal by the converter 4.

Then, when the level of the detected shock pulse exceeds the trigger level value T at the output of the A/D converter 4,
The comparator 12 outputs a trigger level detection signal 1) to the CPU 5.

Then, the CPU 5 stops the counter 13 after 3/4N sampling period from the time when the trigger level detection signal 1) is input (i.e., 3/4NS'l).
A/D conversion is performed in the RAM 10 [after the output of j4 (7) is corrupted, the counter 13 is stopped]. As a result, as shown in FIG. 4, the shock pulse waveform is stored in the RAM 10 in the range from 1/4N before the point Ic to 3/4N after the shock pulse level exceeds the trigger level value T. be done. Therefore, by appropriately determining the value of N and the sampling period, the measured shock pulse waveform can be stored in the area of the RAM 10 without missing any necessary parts.

Note that it is also possible to detect the trigger level at the analog signal stage before the A/D converter 4 instead of detecting the trigger level at the output of the Δ/D'6 converter 4 as in this embodiment. I am an office lady.

Record the shock pulse waveform in RAMIO as described above.
8, then the CPU 5 reads out this stored waveform from the RAM 10 and performs the following calculation (in addition, when reading out the pulse waveform from the RAM 10 in this way, the CPIJ 5 uses the selector 17 'I is switched and RAIv is sent from A1~res bus 8 through selector 171.
input the address signal to llo).

(i) The peak value of the waveform stored in the calculation RAM 10 of the action time [)m, that is, the maximum acceleration A, is distorted. Then, the time D(
0,1Δ). The action time Dm is calculated by substituting this value into the above equation (1). Note that the zero line of the shock pulse waveform is the average value around 1/2 N iJi before the shock pulse level exceeds the tri-force/level value (
The zero line of the pulse waveform is often different from the zero V line at rest).

(11) Calculation of velocity change V The area of the shock pulse waveform is this velocity change V, and the integration range is from 0.1) +++ before the waveform to 0.1 Dm after.

However, a is the acceleration of the impact pulse (unit: G), and 9 is the gravitational acceleration (9.8 m/S''). After the CPU 5 has completed the calculations described above, it calculates the calculation results, that is, the maximum acceleration A, and the action time Dm. and the rapid change ■ are outputted to the LED display 18 through the I10 port 1-17 and displayed on the display 18.

Further, the CPU 5 can also output the calculation result to the printer 16 through the I10 port 15 and cause the printer 16 to print.

Therefore, according to the present device, when an impact pulse is applied, the maximum acceleration Δ, action time Dm, and velocity change V of the pulse can be immediately and automatically obtained.

Although this embodiment has been explained using a half-sine pulse waveform as an example, the present invention can also be applied to the measurement of shock pulse waveforms other than half-sine waves, such as sawtooth waves, trapezoidal waves, etc., in commercial applications. It is something that can be done.

Moreover, the present invention is applicable not only to JIS but also to the measurement of impact pulses according to the same regulations as JIS.

〔Effect of the invention〕

As described above, the impact measuring device according to the present invention complies with JIS and similar standards, and measures the maximum acceleration of impact pulses,
Automatically and quickly measures action time and speed changes.
It has the excellent effect of being able to

[Brief explanation of drawings]

Fig. 1 is a waveform diagram showing the permissible range of the pulse waveform applied to the sample according to JIS, Fig. 2 is a block diagram showing an embodiment of the impact measuring device according to the present invention, and Fig. 3 is the operation of the above embodiment. FIG. 4 is an explanatory diagram showing an example of measuring an impact pulse according to the embodiment. 1... Acceleration detector, 4... △/D converter, 5...
・CPU, 6...Data bus, 7...Control bus, 8...Areas bus, 9...ROM,
10...RAM, 12...Comparator, 13...Counter, 14...Selector, T...Trigger level value. Patent applicant Furuta Seiki Co., Ltd. Ne1 Agent Patent attorney Kyo Omori

Claims (1)

[Claims] an acceleration detector, an A/[) converter that converts an analog signal obtained based on the output of this acceleration detector to Δ/D, and a digital value obtained from the output of this A/D converter or the analog signal. trigger force/level detection means for detecting that the trigger level has reached a predetermined level; and a memory; While cyclically writing to each address of the area, if the trigger level detecting means detects the trigger level, the digital value is written to the area after further writing a predetermined number of words from the time of detection. means for stopping writing of the area; and a distance between points that determines the maximum acceleration of the impact pulse detected by the acceleration detector based on the digital value written in the area, and that is lower than the maximum acceleration by a predetermined level. xi means for calculating an impact duration of the impact pulse based on the impact duration, and further calculating a speed change of the impact pulse based on the impact duration.