JPS6079163A - Diagnostic device for car - Google Patents

Abstract

PURPOSE:To diagnose a starter while it is fitted to a car by correcting the measured rotating speed and measured current of the starter in response to the output of a selection switch specifying the type of a car under measurement and comparing the correction value with a reference value of judge the quality of the starter. CONSTITUTION:At the diagnostic work, first an operation dial 32 is set so that it becomes the same capacity at that of a battery mounted on a car to be tested, and an operation button 33 is operated by type such as gasoline car or diesel car. Next, output signals of the said operation dial 32 and operation button 33 are inputted to a computer 29 together with the output signal of a 12-24V detection circuit 34 judging whether the battery voltage is 12V or 24V. The correction coefficient of the cranking rotating speed and correction coefficient of the cranking current value are calculated by the computer 29, and the cranking rotating speed reference value corrected with these correction coefficients is compared with the rotating speed measured value to judge the quality of the starter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a diagnostic device for automobiles, and more particularly to a device capable of diagnosing everything from light vehicles to large vehicles.

[Background of the invention]

JISD1607 for starter inspection. Rated output is JI
8D5004, these test results are compared with the determination reference value to determine pass/fail. However, when installed in a car, it is difficult to remember the rated output value.

Also, removing the starter from the vehicle and testing it
It's a big time loss.

[Purpose of the invention]

An object of the present invention is to enable diagnosis of a starter while it is mounted on a desk.

[Summary of the invention]

To diagnose the quality of the starter, first detect the cranking rotation speed and compare it with a reference value. The reference value for this judgment can be made almost accurately by distinguishing between light cars, gasoline passenger cars, diesel passenger cars, and large cars.

This distinction can be made based on battery capacity. Since large cars use a 24V battery voltage system, the car is judged to be a large car based on the battery voltage.

Next, the cranking current value of the starter is proportional to the car model and the battery capacity, so if you decide on the criterion value, you can compare and judge by multiplying the cranking current by a correction coefficient depending on the difference in battery capacity. be able to.

The operator adjusts the output capacity by turning a dial. The battery voltages of 12V and 24V are automatically detected by the circuit, and the measured values are multiplied by a correction coefficient and compared with a reference value to judge whether the battery is good or bad.

[Embodiments of the invention]

The details will be explained below according to the diagram.

FIG. 1 is a circuit diagram showing the locations to which the sensors of the diagnostic device or measurement cables are connected.

The (G) wire from battery 1 is connected to start switch 4 and starter 5 magnet switch (also called sub switch).
It is connected to the series coil 6 and shunt coil 7, and when the start switch 4 is operated, the contactor 8 is turned on.
A pinion 11 meshes with a ring gear of an engine 12 via a latch 10 to perform a cranking operation.

On the other hand, the primary coil 1 of the ignition coil 13 passes through the external resistor R1.
4 is applied to the cam of the distributor 16 to connect and disconnect multiple contacts, a high voltage is generated in the secondary coil 15, and a spark is generated in the ignition plug 17.

The diagnostic device 18 has (g) wire 2. Connect the (c) line 3 to the (g) line cable 24 and (c) line cable 25 to use as a power source. It also supplies the built-in battery when the voltage drops.

For gasoline engines, the cranking rotation speed is determined by detecting the intermittent voltage waveform of the ignition secondary coil 11. For diesel engines, the current pulsation during starter operation is detected by the current detector 21, and the cranking rotation speed is calculated. do.

In addition, the voltages at the 8-terminal and M-terminals of the starter 5 are detected to check for defects in the start switch 4 or the main wiring. Connect the current detector 21 and measurement cable.

FIG. 2 shows the operation panel and display panel of the diagnostic device 18.

Set the dial 32 to match the battery capacity used in the test vehicle. Next, the operation button 33 is used to distinguish whether the vehicle is a gasoline vehicle or a diesel vehicle.

FIG. 3 shows a block diagram for correcting diagnostic reference values.

During cranking operation, a resistor R3 is connected to reduce the energy of the secondary coil of the ignition coil 13. and prevent the engine from starting. The cranking rotation speed varies depending on the temperature, and it is determined that the reference value should be equal to or higher than the value shown in FIG. 4. When using this reference value for a gasoline passenger car, the actual measurement data shows that if the corrections shown in Figure 5 are made depending on other differences in battery capacity and whether or not it is a diesel car, a more appropriate judgment can be made.

Furthermore, when determining based on the cranking current value, and assuming that a gasoline passenger car is 1, it has been found from actual measurement data that a nearly appropriate determination can be made using the characteristics shown in FIG.

A control block diagram for making the correction as described above will be explained.

(g) It is applied from the electric wire cable 24 to the constant voltage circuit 26 via the diode Di, and supplies a constant voltage to each control circuit. Battery 30 is charged by resistor R3 and diode D2
It discharges after passing through.

The intermediate terminal voltage of the variable polyneme is changed by the operation dial 32), and via the analog-to-digital converter 28,
It is input to the computer 29.

Also, operation button 3 to distinguish between gasoline and diesel cars.
3 signals are input to the computer. Additionally, 12.24 recognizes whether the battery voltage is 12V or 24V.
The output of the V detection circuit 34 is input to the computer 29.

In this way, the three input signals are processed by the computer 29, and the cranking rotational speed is corrected as shown in Fig. 5, and the cranking current value is corrected and rewritten as shown in Fig. 6. Calculating the coefficient Then, the nine standard values shown in FIG. 4 are multiplied by the correction coefficient and compared with the actually measured value to make a judgment.

According to this method, it is possible to diagnose the starter without removing it from the car, making it possible to diagnose everything from light cars to large cars.

〔Effect of the invention〕

Even if you don't know the capacity of the starter, you can diagnose starters from light cars to large cars.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the locations where sensors or measurement cables of a conventional diagnostic device are connected, FIG. 2 is a plan view of the operation panel of the present invention, and FIG. 3 is a diagram of the diagnostic device of the present invention. The block diagram, FIG. 4 is a conventional cranking rotation diagnostic characteristic diagram, FIG. 5 is a cranking rotation speed correction coefficient diagram according to the present invention, and FIG. 6 is a cranking current correction according to the present invention. It is a coefficient diagram. 1...Battery, 2...(G) wire, 3...(F)
Line, 4...Start switch, 5...Starter, 6
...Series coil, 7...Shaft coil, 8.
...Contactor, 9...Motor, 10...Clutch, 11...Binion bR1...External resistance, 23...
・Measurement cable M112...Engine, 13...Ignition coil, 14...-Secondary coil, 15...Secondary coil, 16...Distributor, 17...Spark plug, 18...Diagnosis 19...Measurement cable I
g, 20...Measuring cable C121...Current detector, 22...Measuring cable S, 24...(G) line cable, 25...(C) line cable, 26...Constant voltage Circuit, 27... Current detection circuit, 28... A-D converter, 29... Computer, 30... Battery, 31...
...Operation input circuit, 32...Dial, 33...Operation button, 34...12°24V detection circuit, R2-...
...Resistor, TR...Transistor. Agent Patent attorney Akio Takahashi 2 countries each $3 4th - Hard J Works Hard J Teso each 11 Hanaotsu Ro Hearts Terri each amount

Claims (1)

[Claims] 1. An automobile starter diagnostic device receives each output voltage signal from an operation dial that outputs an output signal corresponding to the battery capacity and a selection switch that outputs an output signal to distinguish whether the vehicle being tested is a gasoline engine or a diesel engine. the measured rotational speed, the correction value of the means for correcting the measured current,
A diagnostic device for an automobile, characterized in that it has a means for determining pass/fail by comparing judgment reference values and a means for displaying it.