RU213659U1 - Stand for studying the operation of a car instrument cluster - Google Patents

Abstract

The utility model relates to educational and laboratory stands and can be used to study the operation of a car instrument cluster. The technical result of using the proposed stand is to consolidate knowledge of the instrument cluster device, acquire practical skills in determining the sensitivity of sensors and the error of indicators, as well as methods for detecting and eliminating possible malfunctions. The specified technical result is achieved by the fact that in order to consolidate the knowledge of the instrument cluster device, the stand is equipped with automotive toggle switches, buttons and switches that control the operation of signaling devices and indicators as in a real car, the skills to determine the sensitivity of sensors and the errors of indicators are acquired in the process of graphical construction of the dependence of instrument readings on sensor resistance (pulse frequency). To detect possible malfunctions of the instrument cluster, visual observation of the instrument readings and pictograms is used during the sequence (successively switching on) of all toggle switches, regulators and switches.

Description

The utility model relates to educational and laboratory stands and can be used to study the operation of a car instrument cluster.

The training stand belongs to the teaching aids and is used to improve the efficiency of the educational process for the training of road transport specialists. The stand is used in classrooms when performing laboratory and practical work on the electrical equipment of a car, and can also be used as a stand-simulator for acquiring the skills of turning on devices for their intended purpose in a car and identifying malfunctions associated with a car instrument cluster.

A well-known training stand for the lighting system and the light and sound signaling system for vehicles related to teaching aids and is used to improve the efficiency of the educational process for the training of road transport specialists (RU 97557). It allows you to demonstrate the operation of devices of two systems - a lighting system and a light and sound signaling system. It contains a housing on which devices of the lighting system of light and sound signaling are installed, and also has a block of control lamps for monitoring the serviceability of devices of the lighting system and devices of the alarm system, consisting of switching on toggle switches .

The disadvantage of this training stand is its narrow focus, large dimensions, the absence of one central instrument control as on a real car.

Known laboratory stand-simulator vehicle on-board control system (https://labstand.ru/catalog/laboratornye_stendy/tipovoy_komplekt_uchebnogo_oborudovaniya_sistema_bortovogo_kontrolya_avtomobilya_3713?sphrase_id=353288). Designed to study the composition, design and principle of operation of the microprocessor-based on-board control system of a car. The simulator includes a panel with a mnemonic diagram of the on-board control system depicted on it, original parts of the VAZ-2110 car, trouble entry buttons, a coolant level sensor, an oil level sensor, a washer fluid level sensor, a front brake pad wear sensor, a microprocessor system on-board control of the car (display unit), lamp health monitoring relay, door limit switches, brake light sensor, seat belt buckle with sensor, interior lighting and ignition switch.

The disadvantage of this simulator is the use of an outdated microprocessor-based onboard control system in this stand, which covers only half of the sensors and systems used in a modern car. Another disadvantage of this simulator is the use of sensors to take readings, therefore, it will no longer be possible to change the readings manually.

A well-known simulator for determining faults in the car alarm system, containing devices of the car light and sound alarm system, characterized in that all devices are displayed on one panel and there is a fault input system (RU 37430 U1).

The disadvantage of this stand simulator is the lack of measuring instruments, large dimensions and weight, a small number of controlled parameters.

The advantages of the developed stand include demonstrating the operation of a car instrument cluster, simulating various car malfunctions, changing fuel level readings, coolant and ambient air temperatures, deflecting the speedometer and tachometer needles like when a real car is moving with the ability to simulate gear shifting.

The developed training stand (Fig. 1) consists of a housing (Fig. 2, item 1), on which are fixed: a combination of instruments LADA Kalina (Fig. 2, item 2), connected to the stand using a flexible cable; toggle switches for turning on (off) signaling devices of the instrument cluster: a signaling device for not fastened belt (Fig. 2, item 3), anti-lock braking system (ABS) (Fig. 2, item 4), "Check engine" (Fig. 2, item 5), oil pressure (fig. 2, item 6), electronic brake force distribution (EBD) (fig. 2, item 7), immobilizer (fig. 2, item 8), parking brake indicator (fig. 2, item 9), electric power steering malfunction indicator (Fig. 2, item 10); the fault simulation switch (Fig. 2, item 11) includes ten successively switched positions: airbag malfunction (pictogram on the instrument cluster), low brake fluid level (pictogram), turn signal lamp malfunction (double flashing frequency of the turn indicators), malfunction of the car generator (pictogram), malfunction of the fuel level sensor (sharp increase in fuel level), malfunction of the coolant temperature sensor (sudden decrease in coolant temperature), malfunction of the ambient temperature sensor (fixing the temperature at -7 degrees Celsius), malfunction of the headlights lighting (lack of indication on the instrument cluster), malfunction of the speedometer (immobility of the arrow of the speed indicator), power failure of the instrument cluster (complete de-energization of the stand); ignition switch (Fig. 2, item 12), on-board computer button (Fig. 2, item 13), alarm button (Fig. 2, item 14), left/right direction indicator switch (Fig. 2, item 15), gearbox shift simulation unit (Fig. 2, item 16), fuel level regulator (Fig. 2, item 17), coolant temperature regulator (Fig. 2, item 18), ambient air temperature regulator (Fig. 2, pos. 19), terminals for taking sensor readings (Fig. 2, pos. 20), terminals for connecting a multimeter and a pulse generator (Fig. 2, pos. 21, 22), a power on / off switch with a control lamp (Fig. 2, pos. 23), a socket for connecting the power supply (Fig. 2, pos. 24).

The stand for studying the instrument cluster of a car works as follows: an external power supply (14V) is connected to the socket (Fig. 2, pos. 24), using a toggle switch (Fig. 2, pos. 23), power is supplied to the instrument cluster. The readiness of the stand for operation is controlled by a self-diagnosis system, which is activated when the ignition is turned on and the on-board computer button is held down at the same time (Fig. 2, pos. 13). Successive pressing of the on-board computer button displays the firmware version, errors and malfunctions of the instrument cluster on the instrument cluster screen.

Before starting work, the toggle switches and buttons of the instrument cluster are set to their original position: the alarm button "off", the gear shift toggle switch "neutral", the direction indicator toggle switch "off", the outdoor lighting toggle switch "off", toggle switches (Fig. 2, 3-10) to the “off” position, the fuel level, coolant and ambient air temperature regulators are in the leftmost position, the fault input toggle switch is in the “0” position.

After turning the key in the ignition switch to the “I” position, the icons on the instrument cluster light up: “Check engine”, “Battery”, “Low brake fluid level” (briefly), “Not fastened seat belt”, “Immobilizer”, “Low oil pressure", "Airbag", "Parking brake".

After turning the key in the ignition switch to position "II", most of the icons go out, with the exception of "Not fastened seat belt" and "Parking brake", manually controlled by the driver.

To check the fuel level gauge, the coolant temperature gauge and the ambient air temperature displayed on the on-board computer display, it is necessary to change their current readings by turning the regulator corresponding to this indicator, clockwise to increase the readings or counterclockwise to decrease them.

To study the sensitivity of the fuel level sensors, the temperature of the coolant and the ambient air, a multimeter is initially connected to the terminals (Fig. 2, pos. 21) and the voltage readings of the on-board network U _H are recorded. Next, the multimeter is connected to the terminals (Fig. 2, pos. 20) and for different positions of the fuel level regulators, coolant and ambient air temperatures, the current voltage values Ui are recorded. According to formula (1), the resistance of the fuel level sensors, coolant temperature and ambient air is determined

(1),

(one),

where U _H is the voltage of the on-board network, V;

Ui - current voltage value, V;

R _H - nominal value of the sensor resistance, Ohm;

R _D - current resistance of the sensor, Ohm.

The sensitivity of fuel level sensors, coolant temperature and ambient air temperature sensors is determined by formula (2) as the ratio of elementary increments of the fuel level (temperature) dh(dT) to the resistance increment dR

The operation of the speedometer and tachometer depends on the position of the gearbox simulation switch (Fig. 2, item 16). In the neutral position of the switch, the readings of the tachometer and speedometer are equal to zero. When the ignition is turned on (pos. II of the ignition switch), the tachometer needle rises to 800 rpm, and the speedometer needle remains at zero, regardless of the tachometer readings and pulse frequency.

When the switch is moved to the "First Gear" position, the speedometer needle will be adjusted simultaneously with the tachometer readings. When the switch is moved to the “Second Gear” position, the tachometer needle will drop down one thousand revolutions per minute, while the speedometer needle will remain in the same position. A further increase in the pulse frequency will lead to a synchronous increase in the speedometer and tachometer readings. This process will be repeated when the switch is moved to the "Second, third, ..., sixth gear" position. When switching positions in the opposite direction, the process will occur exactly the opposite.

To determine the error of the speedometer and tachometer, a pulse generator is connected to the terminals (Fig. 2, pos. 22). When the transmission simulation toggle switch is moved to the first speed position, the tachometer needle deviates to the idle position. An increase in the frequency of pulses on the generator leads to the deviation of the arrows of the tachometer and speedometer from left to right. To determine the error, the obtained values are compared with the passport data of the instrument cluster (Table 1) according to the formula (3).

,

,

- погрешность спидометра на i-той скорости движения, %;where

- error of the speedometer at the i -th speed, %;

f _And - the frequency of the generator at the i -th speed, Hz;

f _H - passport frequency for the i -th speed, Hz.

To search for simulated malfunctions of the instrument cluster, visual observation of the instrument readings and pictograms is used during the sequence (successively switching on) of all toggle switches, regulators and switches. In this case, it is possible to detect a malfunction of the control lamp responsible for a particular system, failure or implausible readings of pointers, as well as other malfunctions. An example of a troubleshooting algorithm is shown in Fig. 3.

Table 1 - Data for checking the speedometer and tachometer

Rated speed, km/h Permissible input signal frequency range, Hz 40
80
120
160
200 59.42-66.56
124.18-133.13
187.05-199.7
249.93-266.26
312.81-332.83 Numerical marks of the tachometer, min -1 Permissible input signal frequency range, Hz 1000
3000
5500 28.76-38.02
94.43-105.69
176.53-190.27

Fig. 1 - Drawing of the stand.

Fig. 2 - Arrangement of stand elements.

Fig. 3 - Troubleshooting algorithm.

Thus, in comparison with the prototype, the training stand for studying the operation of a car instrument cluster allows you to simulate the operation of all control lamps and devices, determine the sensitivity of sensors and the error of indicators, and also acquire troubleshooting skills.

Claims (3)

1. A training stand containing a housing on which the instrument cluster of the car is fixed with screws, as well as toggle switches for controlling the signaling devices of the instrument cluster, potentiometers that allow you to adjust the fuel level, coolant and ambient air temperature, terminals for connecting a multimeter and an oscilloscope, a button that allows you to switch data on the on-board computer display, vehicle speed and crankshaft speed control, alarm button and turn signal switch combined into one electrical circuit and working like on a real car, fault input switch, ignition switch that regulates the power supply to on-board instruments network, stand power switch, characterized by the presence of a fault simulation unit, which includes 10 sequentially switched positions: airbag malfunction, low brake fluid level, turn indicator lamp malfunction ta, car alternator malfunction, fuel level sensor malfunction, coolant temperature sensor malfunction, ambient air temperature sensor malfunction, headlight malfunction, speedometer malfunction, instrument cluster power failure. 2. Stand according to claim 1, characterized by the presence of a built-in pulse generator, which, when connected to an external signal frequency meter, allows you to determine the error of the vehicle speed and crankshaft speed indicators. 3. Stand according to claim 1, characterized in that by connecting a multimeter, it is possible to laboratory determine the sensitivity of the built-in sensors for fuel level, coolant temperature and ambient air.

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