Fig. 3.14. Removal from gearing of a safety lock of a cowl

Fig. 9.50. Combination of devices (rear view)

For control of systems the car is equipped with a combination of devices in which control devices are installed: the index of tension, a tachometer, a speedometer, the index of temperature of the engine, the index of pressure of oil, the index of level of fuel and signaling devices (see fig. 3.14). Connection of contacts of a combination of devices is shown on electric circuits, and an arrangement of electric sockets in fig. 9.50. The procedure for test of serviceability of devices is provided below.

For removal of a combination of devices previously remove facing, having unscrewed four screws. Then unscrew four screws of fastening of a combination; separate electric sockets and remove a combination of devices. You make repair of a combination of devices block replacement of faulty devices. For replacement of devices remove protective glass and on a reverse side turn off nuts of fastening of the faulty device.

In a combination of devices the electronic speedometer with the step electric motor is established. The speedometer consists of the arrow index of speed, the counter of the passable way and the daily counter of the passable way. The daily counter has the button of dumping of indications. The speedometer works complete with the electronic sensor of Hall installed on the transmission. At the movement of the car the sensor is given to rotation from a gear wheel of a secondary shaft of the transmission. For one turn of a shaft of the sensor 6 impulses of electric current are developed. These impulses come to a speedometer chip, will be transformed and arrive on the microampermeter which indicates car speed, and the step electric motor which rotates barabanchik of indexes of the passable way.

Fig. 9.51. Electric circuit of check of a speedometer: 1 — I will corrode shtekerny HRZ of a combination of devices, 2 — the generator of signals G5-54, 3 — the rechargeable battery

For check of serviceability of a speedometer it is necessary to collect the electric circuit shown on rice. 9.51. Give the generator of signals G5-54 on conclusions No. 10 and No. 3 of the HRZ socket squared impulses, positive polarity with an amplitude of 6+1 V lasting 200 — 250 microsec. Accuracy of indications of high-speed knot in control points has to keep within:

60 km/h — 93,7 — 100 Hz

100 km/h — 157,2 — 166,6 Hz

By the same principle the accuracy of indications of calculating knot is checked.

With a frequency of 100 Hz in one minute the barabanchik of "Km/h" has to turn on 1 figure. The error of calculating knot should not exceed +1%.

Fig. 9.52. Electric circuit of check of the sensor of a speedometer: 1 — a socket key, 2 — the socket shtekerny the sensor, 3 — the rechargeable battery, R1 — resistance of MLT-0,25-10 of kOhm, V1 — AL102 light-emitting diode

For check of the sensor of a speedometer collect the electric circuit shown in fig. 9.52. For one turn of the roller of the sensor the light-emitting diode has to flash 6 times.

In a combination of devices the electronic tachometer for measurement of frequency of rotation of a bent shaft of the engine is established.

The tachometer consists of the milliamperemeter and the electronic scheme. Alternating voltage from the generator (undertakes to the vypryamitelny block from a stator phase) arrives in the amplifier, then will be transformed in a chip and comes to the milliamperemeter which arrow shows speed. The frequency of rotation of the generator is higher, the more impulses of alternating current come to an electronic part, on a bigger corner the arrow of a tachometer deviates by that.

Fig. 9.53. Electric circuit of check of a tachometer: 1 — I will corrode shtekerny HRZ of a combination of devices; 2 — the rechargeable battery; 3 — the generator of signals G5-54

For check of a tachometer collect the electric circuit shown in fig. 9.53. From the generator of signals G5-54 give on conclusions No. 1 and No. 6 of the HRZ socket squared impulses, positive polarity with an amplitude of 12-2 V and lasting 200 — 250 microsec. With a frequency of 240 Hz the tachometer has to show 1000+100 ^min.-1, and with a frequency of 960 Hz — 4000 ^min.-1.

In a combination of devices the electromagnetic index of level of fuel working complete with the sensor installed in a petrol tank is established.

The index is an electromagnetic crossed-coil instrument with motionless measuring coils and a mobile permanent magnet. The magnet is strengthened on an index arrow axis. Coils of the index are reeled up at an angle in 90 ° on a special plastic framework. A framework with coils and a magnet are placed in the special screen for an exception of influences of foreign magnetic fields on them.

At course of current on both coils the resulting magnetic field is created. A permanent magnet, interacting with magnetic field of coils, is established in the situation depending on the direction of this field. The direction of the resulting magnetic field depends on change of the relation of currents in coils which is defined by the size of resistance of the sensor depending in turn on amount of fuel in a tank.

Rice. 9.54. Electric circuit of verification of the index of level of fuel: 1 — I will corrode shtekerny HRZ of a combination of devices; 2 — the rechargeable battery; 3 — I will corrode shtekerny XP1 of a combination of devices, 4 — the switch, R1 — resistance of MLT-2-330 of Ohms, R2 — resistance of MLT-2-120 of Ohms, RZ — resistance of MLT-2-15 of Ohms

For verification of the index of level of fuel it is necessary to collect the electric circuit shown in fig. 9.54. At inclusion of resistance of RI, the shooter has to show "0", at inclusion of R2 — "1/2", and at inclusion of R3 — a full tank. An arrow deviation from the specified divisions no more than on arrow width. The serviceable sensor of the index of level of fuel has to have the following resistance: — at completely lowered float of 330+15 Ohms, and at completely lifted — 11+5 Ohms. At an intermediate position of a float of 70 mm from a sensor flange to the lower part of a float (the measurement is made perpendicular to a flange) resistance has to be 118+10 Ohms.

In a combination of devices the electromagnetic index of temperature of cooling liquid of the engine of logometrichesky type is established.

The device consists of the index and the sensor installed in the engine. The device of the index is similar to the index of level of fuel, and the sensor — the semiconductor thermoresistor which is sharply changing the resistance depending on changes of temperature. Change of temperature of cooling liquid changes sensor resistance that causes change of current in coils of the index and the resulting magnetic field turns a permanent magnet and an arrow in the relevant provision of a scale.

The serviceable sensor at 25 °C has to have resistance of 1400 — 1900 Ohms, and at a temperature of 80 °C of 200 — 270 Ohms.

Fig. 9.55. Electric circuit of verification of the index of temperature of cooling liquid: 1 — I will corrode shtekerny HRZ of a combination of devices; 2 — the rechargeable battery; 3 — I will corrode shtekerny XP1 of a combination of devices; R1 — resistance of MLT-2-250 of Ohms

For verification of the index of temperature of cooling liquid it is necessary to collect the electric circuit shown in fig. 9.55.

The arrow of the index should not deviate division of 80 °C more, than on arrow width.

In addition to the index of temperature of the cooling system the car is supplied with an engine overheat signaling device. The sensor automatically includes a lamp in combinations of devices when temperature of cooling liquid reaches 104 — 109 °C.

The electromagnetic index of logometrichesky type is applied to control of pressure in the lubrication system of the engine. The device consists of the index located in a combination of devices and the sensor 23. 3839. The device of the index is similar to the index of level of fuel, and the sensor represents the variable resistance which size changes depending on the provision of a membrane which in turn changes the situation from pressure size.

Fig. 9.56. Electric circuit of verification of the index of pressure of oil: 1 — I will corrode shtekerny HRZ of a combination of devices; 2 — the rechargeable battery; 3 — I will corrode shtekerny XP1 of a combination of devices; 4 — the switch; R1 — resistance of MLT-2-180 of Ohms; R2 — resistance of MLT-2-60 of Ohms

For verification of the index of pressure of oil it is necessary to collect the electric circuit shown in fig. 9.56. At connection of resistance of R1 the index has to show ^{pressure of 1,5 kg/cm2}, and at connection of resistance of R2 — 4,5 ^kg/cm2. An arrow deviation from the specified points no more than on arrow width.

The serviceable sensor has to have resistance of 290 — 330 Ohms in the absence of pressure, with ^{a pressure of 1,5 kg/cm2 of 170 — 200 Ohms}, and with ^{a pressure of 4,5 kg/cm2 of 50 — 80 Ohms}.

In addition to the index of pressure of lubricant in a combination of devices there is a signaling device. At pressure decline in the engine lubrication system from 0,4 — 0,8 ^kg/cm2 in a combination of devices the signaling device lights up. The signaling device works with the MM111-B sensor. In the absence of pressure in system the membrane of the sensor is curved from contacts aside and the lamp lights up, and in the presence of pressure the membrane is curved to the opposite side, disconnects contacts and the lamp dies away.

The index of tension of logometrichesky type, with motionless windings. The device of the index of tension is similar to the index of level of fuel.

Fig. 9.57. Electric circuit of verification of the index of tension: 1 — an adjustable source of a direct current, 2 — the control voltmeter, 3 — I will corrode shtekerny HRZ of a combination of devices

For verification of the index of tension it is necessary to collect the electric circuit shown in fig. 9.57.

For control it is necessary to use the voltmeter with a limit to 30 V of a class I and an adjustable source of a direct current (for example B5-48). Changing source tension, to determine the accuracy of indications of the index of tension of a combination of devices by the control voltmeter. The error of the index of tension in points of 12 and 14 V should not exceed +0,4 Century.