SU1472287A1 - System for automatic control of air pressure in vehicle tyres - Google Patents

Abstract

The invention relates to automotive engineering, in particular, to systems for adjusting air pressure in tires of wheeled vehicles, preferably fertilizer spreaders. The purpose of the invention is to increase the efficiency of use on machines with variable on-the-go loading by adjusting the sensitivity and shutting down the device during overloads. The system contains a source 11 of compressed air, forcing and bleeding lines, a solenoid valve 7, a pressure sensor 10, a vertical load sensor 1, an integrator 2,3, a block for limiting the allowable tire pressure, an alarm unit 4, a adjusting resistor 5, a comparison unit 6, amplifiers 8 and 9 power and pressure reducing valve 12. 5 Il.

Description

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The invention relates to automotive engineering, in particular, to devices for adjusting air pressure in tires of wheeled vehicles, advantageously natural fertilizer spreaders.

The purpose of the invention is to increase the efficiency of use on machines with changing us.s on-the-go loading by adjusting sensitivity and shutting it down when overloaded.

FIG. 1 is a block diagram of an automatic tire pressure regulation system for vehicle tires; in fig. 2 is a graph (timing diagram) illustrating the signal taken from the vertical load cell; in fig. 3 is a graph (timing diagram) illustrating the transformed signal taken from the integrator and limited to the input of its device; in fig. 4 - the characteristic, on a yush, and work I limit, its devices; in fig. 5 are graphs illustrating the change in the output signal of the vertical load sensor from the load on the wheels and the corresponding change in air pressure in the tires to maintain their optimum deformation.

The automatic tire pressure control system of the vehicle includes a vertical load sensor 1, integrator 2, device 3, limiting tire pressure limits, alarm unit 4, control resistor 5, comparison unit 6, solenoid valve 7 and power amplifiers 8 and 9, and also a pressure sensor 10, a source of compressed air and a pressure reducing valve 12.

The vertical load sensor can either be a strain gauge (on the half-axle sleeves) or inductive in a tire. The integrator serves to smooth the oscillations of the load and thereby to prevent unnecessary activation of the solenoid valve, i.e. . to increase the service life of the electromagnetic valve. The device 3 serves to limit the allowable tire pressure when the machine is overloaded. The alarm unit is designed to notify the driver about the need to reduce the speed during overloading the machine.

A comparison device acts on the actuator valve. When the maximum permissible tire pressure is exceeded at a given load on the wheels, air is blown out of the tires by acting on the solenoid valve, and when the tire pressure drops below the minimum permissible at a given wheel load, the tires are inflated.

Using a sensor and sensor communication through an integrator with a limiting device

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by means of the latter, the maximum allowed tire pressure is set. With the help of an adjusting resistor, the minimum allowable tire pressure is set. Thus, depending on the load coming on the wheels, the required tire pressure will be maintained, which ensures optimal deformation of the tires regardless of the load. A pressure sensor is used to obtain information about tire pressure values. A pressure reducing valve limits tire pressure in the event of a system failure. The automatic system works as follows.

The vertical load sensor 1 provides information about the value of the vertical load; its negative output is proportional to the load. The signal, by the value of which the upper limit of air pressure regulation in tires is set, from sensor 1 is fed to the input of integrator 2, where it is integrated (an average value is given) and fed to the input of device 3 (Fig. 2). Device 3 includes a resistor, a zener diode, and serves to determine the upper limit of the working range of tire pressure adjustment.

When a fertilizer spreader is moving, there is a constant change in the load on the wheels caused, on the one hand, by unevenness of the bearing surface, and on the other, by gradual unloading of the machine's hopper during the process of fertilizer application. In this case, the signal taken from the load cell oscillates around the average value (Fig. 3). To smooth out high-frequency load oscillations caused by uneven ground surface, integrator 2 serves. The signal taken from integrator 2 is fed to the input of the limiting device 3 and looks like shown in FIG. 2

The signal taken from the limiting device 3 is fed to the input of the alarm unit 4 (Fig. 1), which is a comparator, the inverting input of which is connected to the output of the limiting device 3, and the non-inverting one with the reference voltage Uon, slightly lower voltage stabilization stabilitron UcmaS. The output signal of the limiting device is proportional to the load on the wheels at values less than the maximum 50 GMAW permissible (Fig. 4). When loads are large, the voltage at the output of the limiting device becomes equal to UcwJ. In this case, the comparator of the UcmoS U alarm unit is triggered and the driver is given a light signal on the need to reduce the speed of movement. The signal taken from the limiting device sets the upper limit of the zone

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insensitivity (Fig. 5), i.e. the zone within which the spool of the solenoid valve 7 is in the neutral position. The adjusting resistor 5 sets the lower limit of the dead zone.

The introduction of the dead zone allows a drastic reduction in the number of actuations of the solenoid valve 7, and consequently, an increase in its operational life.

When the air pressure in the tires exceeds the upper limit of the dead zone (Fig. 5), the signal from the sensor 10 has a value greater than the signal taken from the limiting device 3. This triggers the lower comparator of the comparison device 6 and acts through the power amplifier 9 on the valve 7 whose spool occupies the extreme right position. Bleeding of air from the tires into the atmosphere occurs. When the magnitude of the pressure enters zone 2, the effect is removed from the solenoid valve 7 and it is set to the neutral position.

When the air pressure in the tires is lower than the lower limit of the dead zone (Fig. 5), the signal from the sensor 10 has a magnitude lower than the signal taken from the output of the adjusting resistor 5. The upper comparator of the comparing device 6 operates and operates through the electromagnetic amplifier 8 pan 7. The latter connects the tires with a source of compressed air 11. The tires are pumped until the pressure value falls into the dead zone (Fig. 5).

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In this way, tire pressure adjustment is achieved, ensuring optimum tire deformation regardless of the vertical load on the wheels.

Claims (1)

Invention Formula An automatic air pressure control system in vehicle tires, containing a source of compressed air, forcing and bleeding lines, a valve for controlling the discharge and bleeding of air, an internal pressure sensor for air, a vertical load sensor, and a comparison unit, In order to increase the efficiency of use in applications with variable loading, by adjusting the sensitivity and disconnecting it in case of overloads, it is equipped with an integrator tire pressure in case of overloads, an alarm unit, an adjusting resistor and a power amplifier, and the air discharge and air control valves are made electromagnetic, and the power amplifier is connected to the valve with its outputs, and the inlets are compared to the outputs of the comparison unit, the output of the vertical load sensor is connected to the input of the block for limiting the allowable tire pressure through the integrator, and the output of this block to the signaling unit, to the first input of the comparison unit and to the regulator input th resistor, the output of which is coupled to the second input of the comparison unit, whose third input. connected to the output of the internal pressure sensor. ) (.. sensor ffup. J and Btiix. ) f (vf BaM7Ufesff devices t / crrra. 0 G tax el