JPS63274837A - Inspection device for automobile - Google Patents

Abstract

PURPOSE:To facilitate the operation of an oscilloscope by providing the oscilloscope, an oscilloscope operation assisting device connected thereto, etc. CONSTITUTION:When the oscilloscope 10 is used, its power source is applied, and then an initial setting part 12 displays a bright line of each channel on a display screen 11. Then a trigger control part 13 is set properly, a measurement probe 21 is applied to on-vehicle equipment to be measured, and a time- base setting knob 14 and vertical axis setting knobs 15 and 16 are set at every measurement point, thereby taking a measurement. Then when the probe 21 is applied to the measurement point so as to display an invariably proper vertical axis set value to an operator, proper vertical axis set values are displayed on displays 32 and 42 of the oscilloscope operation assisting device 20. Thus, the operation of the oscilloscope is facilitated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an inspection device for an automobile that inspects devices such as electrical components mounted on an automobile and their systems, and particularly relates to an oscilloscope and its operation. This relates to an automobile inspection device equipped with an oscilloscope operation support [f] to facilitate the operation of automobiles. [Prior art] In recent years, the use of car electronics in automobiles has been remarkable.
Fuel injection electronic control systems are one example. When inspecting and maintaining this control system, for example, crank angle sensor signals, ignition control signals, fuel injector drive signals, etc. have pulse waveforms, and conventionally, ECC5
It used to be possible to inspect the vehicle with a checker, but many modern cars do not have checker terminals, so it has become necessary to use an oscilloscope to inspect the electrical system. Inspection using an oscilloscope is
This is because, compared to conventional checkers, it has the advantage of being able to measure all input and output signals and extending the detection range.

[Problem that the invention seeks to solve]

However, it is difficult for maintenance tools to master the oscilloscope in a short period of time, especially when setting the oscilloscope's vertical axis setting knob to an optimal value that does not overscale, or when the measurement target changes one after another. There are problems in that operations such as changing the setting of the vertical axis optimum value are time consuming and inefficient, and errors in setting the vertical axis value prevent proper inspection.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an object of the present invention is to provide an automobile inspection device equipped with an oscilloscope operation support device that allows easy operation of an oscilloscope.

[Means for solving problems]

To achieve the above-mentioned object, the present invention includes an oscilloscope, an oscilloscope operation support device connected to the oscilloscope, and an oscilloscope, which receives, for example, an ignition device output signal, a fuel injection device output signal, or a charging signal from on-vehicle equipment. A is intended for an automobile inspection device that inspects in-vehicle equipment by inputting measurement signals such as output signals to the oscilloscope and the oscilloscope operation support device, respectively.

The oscilloscope operation support device includes the following means. Namely.

A signal attenuation means having, for example, a group of resistors and a group of switches, which can input the measurement signal and change the attenuation ratio over a plurality of stages.

A signal holding means, such as a peak value hold circuit or (and) an average value hold circuit, which holds the value of the measurement signal output at a predetermined level by the signal attenuation means, and converting the held signal of the signal holding means into quantification. Quantity converting means for converting the number of signals into the above quantity by controlling the signal holding means to maintain a predetermined level value by initializing the holding means (a) and selecting the attenuation ratio of the signal attenuation means; The converted value is read through the conversion means, a measured signal value is calculated from this and the signal attenuation ratio, and this is compared with a pre-stored setting value of the vertical axis setting knob of the oscilloscope so that the ratio of the two becomes within a predetermined range. The present invention is characterized by comprising a data processing means for determining a set value, and a display means for displaying the knob setting value determined by the data processing means on a display section.

[For production]

The oscilloscope operation support device detects the peak value or average value of the input signal, and automatically calculates and selects the optimum vertical axis setting value of the oscilloscope that does not overscale based on the detected value.

And by displaying this vertical axis optimal value.

Since the user only has to operate the vertical axis setting knob of the oscilloscope according to this display, it is easy to set and change the vertical axis knob, thereby shortening the operation time and reducing operational errors.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is a front view of the inspection device according to the embodiment, Figure 2 is an enlarged plan view of the vertical setting knob in the inspection device, Figure 3 is an internal wiring diagram of the oscilloscope operation support device, and Figure 4 is the oscilloscope operation. It is a flowchart for explaining the operation of the support device.

First, the entire automobile inspection system will be described with reference to FIG. 1. In FIG. 6, 10 is a known oscilloscope that can use two channels, and 21 is a probe for signal measurement. 2
0 is an oscilloscope operation support device, with a channel 1 display section 30 on the front.

A channel 2 display section 40 is mounted separately.

The channel 1 display section 30 displays the peak value of the signal,
A display mode selector switch 31 for selecting average value display and a vertical axis setting value display 32 of the oscilloscope 10.
and a ■ or mV switching display section 33. Similarly, the channel 2 display section 40 has a display mode changeover switch 41, a vertical @ set value display 42 of the oscilloscope 10, and a changeover display section 43.

The probe 21 is connected to the oscilloscope 10 and the oscilloscope operation support device 20 so that measurement signals can be supplied to each. The oscilloscope 10 has a display section 11
, initial setting section 12) trigger control section 131 time axis setting section 14. and vertical axis setting knobs 15 and 16. An example of this vertical axis setting knob 15.16 is
As shown in the figure. In this example, vertical axis setting knobs 15 and 16.

This means that it can be set in a range from 5 mV to 5 V per minimum scale on the display surface.

FIG. 3 is an internal wiring diagram of the oscilloscope operation support device 20. As mentioned before, the measurement signal from the probe 21 is connected to the resistor rn51 of the oscilloscope operation support device 20 on one side, and to the input section of the oscilloscope 10 on the other side.
They are connected to each other so that they can be input.

A resistor group 51 in which a plurality of resistors having different electrical resistance values are connected in parallel is connected in series with a switch group 52.
3. 54 is an operational amplifier, the output of which is input to a peak value hold circuit 64 consisting of a diode 55, a capacitor 56 and a switch 57 on one side, and an average value hold circuit 65 consisting of a resistor 58 and a capacitor 59 on the other side. It looks like this.

60 and 62 are comparators, 61 is a digital/analog (D/A) converter, and 63 is a microcomputer. The comparator 60 uses the output of the peak value hold circuit 64 as one input, the low input as the output of the D/A converter 61, and inputs the output to the microcomputer 63. The comparator 62 uses the output of the average value holding circuit 65 as one input, uses the low input as the output of the A/D converter 61, and inputs the output to the microcomputer 63. The operation of selecting one switch from the switch group 52 and the selected switch and switch 57
The on/off operation is controlled by a microcomputer 63. The D/A converter 61 is for converting a digital signal from the microcomputer 63 into an analog signal.

The vertical axis optimum setting value calculated and processed by the microcomputer 63 is displayed on the display 32.

The switch 31 is the aforementioned display mode changeover switch, and the display mode (peak value display mode or average value display mode) signal selected by this switch 31 is input to the microcomputer 63.

The operation of the automobile inspection device having the above configuration will be explained.

The procedure for using the oscilloscope 10 is to turn on the power, and then set the display screen 11 to the initial setting section 12.
Display the bright lines for each channel.

Next, set the trigger control unit 13 appropriately, apply the measurement probe 21 to a device to be measured such as an ignition device, fuel injection device, or charging device installed in the vehicle, and turn the time axis setting knob 14 and the vertical axis setting knob 15° 16. It is common to set and measure each measurement point.

Here, the operator may have to change settings each time the measurement point is changed using the setting knob 14. Of ts or 16, especially vertical 41I! l Setting knob 15
．． Regarding No. 16, if the set value of the vertical axis is not appropriate, the waveform will not be displayed on the display surface 11, or even if it is displayed, the waveform will be too large or too small, making the display unsuitable for inspection.

Therefore, in order to display the correct vertical axis setting value to the operator at all times, the present invention provides a display 32 of the oscilloscope operation support [20] when the probe 21 is placed on the measurement point.
．． 42, appropriate vertical axis setting values are displayed.

The operation of the oscilloscope operation support device 20 shown in FIG. 3 will be explained in conjunction with FIG. 4.

The probe 21 shown in FIG.
When the power is turned on, the microcombi 63 in the oscilloscope operation support opening 20 performs sequence control operations as shown in FIG.

That is, when starting, in step (hereinafter abbreviated as S), the display mode changeover switch 31 of channel 1 display section 30 or channel 2 display section 40 is
The switch state of the display mode selector switch 41, that is, whether it is the peak value display mode or the average value display mode, is inputted into the microphone computer 63, and is stored in a predetermined RAM address. Ru.

Next, in step 82, one of the switches $52 is selected and turned on so that the attenuation value determined by the grip group 51 and the resistor 53 for the measurement signal from the probe 21 is maximized. At N3, it is determined whether the mode set by the display mode changeover switch 31 or 41 is the peak value display mode or the average value display mode, and if it is the former, the process proceeds to N4, and if the latter, the process proceeds to the previous stage of N5.

Then, by temporarily closing the switch 57 of the peak value bold circuit 64, the capacitor 56 is discharged (N
4) Set N=O at N5, then wait for a certain period of time at S6 (time for the capacitor 56 to complete charging even when the input value is at its maximum), and output to the D/A converter 61 first from N2:0 (S7) .

Then, in N8, the mode setting is determined, and if the determination result is the peak value display mode, the process advances to the next step 89.
If it is the average value display mode, the process advances to 810, where it is determined whether or not there is an output to the comparator 62. If it is determined that there is an output, the process advances to the previous stage of Sll.

The output of the D/A converter 61 is an analog value.

A comparator 60 connects this output with the output of the capacitor 56.
Comparatively, 89), D is equal to the potential at the end of the capacitor 56.
If the output of the /A converter 61 is given, the comparator 60 outputs a match signal and proceeds to the first order 511. If the match signal is not output, the comparator 60 outputs a match signal from 0 to N+4 → N
S10), update the value until a matching output is obtained from the comparator 60, and obtain the digital conversion value N when matching is obtained. Here, for example, when the maximum value that can be input to the D/A converter 61 is Nmax, 8o%Nmax
x>30%...If N satisfies [(1) equation (811)), it is considered valid, and the absolute value of the peak voltage of the input signal is calculated from this and the attenuation ratio (S12).

On the other hand, if the above formula (1) is not satisfied, switch group 5
1, the switch of the circuit whose resistance attenuation ratio is one step lower than the previous one is selected from the switch group 51 and turned on (S 1
3), repeat the series of operations from N3 to Sll as described above (1).
) Repeat until the formula is satisfied.

Next, in 512, after calculating the absolute value of the peak voltage of the input signal, this voltage value is converted into the voltage value (V r ) per division of the vertical axis in the oscilloscope 10! A calculation 5
14) Do. On the other hand, the settable vertical axis setting value (V m ) of the oscilloscope 10 that has been stored in advance is set to 315.
90%>V starting from the minimum value (or maximum value) of Vm
m/Vr>50%... ((2) formula (316)
), and if the minimum value does not satisfy the above formula (2), update the Vm value (S17),
The Vm value obtained when the equation (2) is satisfied is displayed on the vertical axis set value display 32 or 42 (818).

The operator only has to set the vertical axis setting knob 15 according to the indication on the display 32 or 42.

Furthermore, even if the item to be measured is changed, the optimal vertical axis setting value of the oscilloscope is automatically calculated and displayed by performing the series of operations described above.

〔Effect of the invention〕 This is because the present invention has the configuration as described above.

The vertical axis setting value of the oscilloscope can be set appropriately and easily, which makes the use of the oscilloscope extremely simple, reduces the setting time, and provides a highly reliable automobile inspection device. .

[Brief explanation of the drawing]

FIG. 1 is a front view of an inspection device according to an embodiment of the present invention, FIG. 2 is an enlarged plan view of a vertical setting knob in the inspection device, FIG. 3 is an internal wiring diagram of an oscilloscope operation support device, and FIG. 4 is a flowchart of the oscilloscope operation support device. 10...Oscilloscope, 15.16...
... Vertical axis setting knob, 20 ... Oscilloscope operation support device, 21 ... Probe, 30 ...
...Channel 1 display section, 31...Display mode selection switch, 32...Vertical axis setting display, 33...Switching display section, 40...
...Channel 2 display section, 41...Display mode selection switch, 42...Vertical axis setting value display, 43...Switching display section, 51...
・Resistance group, 52...Switch group, 63...
... Microcomputer, 64 ... Peak hold circuit, 65 ... Average value hold circuit. Figure 1

Claims (3)

[Claims] (1) An inspection device for an automobile that includes an oscilloscope and an oscilloscope operation support device connected to the oscilloscope, and inspects the in-vehicle device by inputting measurement signals from the in-vehicle device to the oscilloscope and the oscilloscope operation support device, respectively: The oscilloscope operation support device includes a signal attenuation means whose attenuation ratio can be changed in multiple stages by inputting the measurement signal, and a value of the measurement signal outputted at a predetermined level by the signal attenuation means. a signal holding means; a quantity converting means for quantifying and converting the signal held by the signal holding means; and initial setting of the signal holding means and selection of an attenuation ratio of the signal attenuation means to set the signal holding means at a predetermined level value. The converted value of the held signal is read through the above-mentioned quantity conversion means, the measured signal value is calculated from this and the above-mentioned signal attenuation ratio, and the measured signal value is calculated from this and the previously stored vertical axis setting knob of the above-mentioned oscilloscope. and a display means for displaying the knob setting value obtained by the data processing means on a display unit. An inspection device for automobiles. (2) The automobile inspection device as set forth in claim (1), wherein the signal holding means is constituted by a peak value holding circuit. (3) The automobile inspection device as set forth in claim (1), wherein the signal holding means comprises an average value holding circuit.