FIELD OF INVENTION

The invention relates to safety braking systems for self-propelled vehicles used, primarily, for agricultural purposes. PRIOR ART

Various safety braking systems are known for emergency braking of vehicles.

A control system for a vehicle parking brake is known from Patent US 3985210, publication date 1976-10-12, IPC B60T-007/12, wherein the brake is activated when fluid pressure in a hydraulic circuit is relieved. The system includes an electric circuit for energizing a solenoid that holds the spring of pressure-relieving valve of the hydraulic circuit in the closed position. At emergency braking, the solenoid is de-energized thus releasing the spring and opening the pressure relief valve of the hydraulic circuit and activating the brake.

The closest analog to this invention is described in Patent GB 2453523, publication date 2011-11-09, IPC B60T-007/22, which discloses an automatic vehicle braking system. The system features at least one spring-loaded brake having a pneumatic cylinder connected to a compressed air feed line. When pressurized, the pneumatic cylinder compresses the spring and releases the brake. The system also includes a valve connected to the compressed air feed line going to the spring brake, and an impact sensor for impact detection. When the sensor detects an impact, the valve is actuated, the air in the pneumatic cylinder is vented and the emergency brake is activated.

SUMMARY OF THE INVENTION

The technical result achieved by the invention consists of enhancing the reliability of stopping a vehicle at emergency braking. The safety braking system of a self-propelled vehicle includes a DC power supply connected through an electric energy transmission circuit to a controller, which is connected, in particular, to electric motors of the propulsion system of the self-propelled vehicle. The controller output is also connected to the power supply circuit of an air compressor, whose air feed line is connected to pneumatic brake cylinders of the braking mechanism. Whereas, each braking mechanism is disabled when the air feed line is under pressure. The air feed line is equipped with at least one controlled pressure relief valve for venting the air, which is controlled by the above controller, with said electric energy transmission circuit including at least one circuit breaker. The braking system is intended for electrically driven vehicles, whose operation mode is set by a controller. The reliability of emergency stopping of self-propelled vehicle is improved because, when stopping is necessary, the electric motors of self- propelled vehicle are switched off simultaneously with brake activation. This allows for a faster and more reliable vehicle stopping. At least one push-button switch can be installed on the self-propelled vehicle as a circuit breaker.

At least one emergency circuit breaker can be installed as a circuit breaker.

More particularly, the braking mechanism includes a drum brake.

In particular case, the pneumatic brake cylinder of the braking mechanism can additionally include a spring return mechanism. to increase the overall reliability.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a structural diagram of the safety braking system of a self-propelled vehicle.

Fig. 2 shows a drive mechanism from the electric motor to the brake and drive. Fig. 3 shows a front view of pneumatic cylinder design with a spring return mechanism.

Fig. 4 shows a side view of pneumatic cylinder design with a spring return mechanism.

Fig. 5 shows a side view of self-propelled vehicle. Fig. 6 shows a rear view of self-propelled vehicle.

EMBODIMENTS OF THE INVENTION

The safety braking system is intended primarily for emergency stopping at an obstacle, or for stopping in a situation that threatens the human personnel located on or near the self-propelled vehicle. The safety braking system of a self-propelled vehicle 1 (Fig. 1, Fig. 5, Fig. 6) includes a DC power supply 2 connected through an electric energy transmission circuit to controller 3. Electric motors 7 of track drives 17 are connected to controller 3.

Air compressor 4 connected to the output of controller 3 has its air feed line 5 connected to pneumatic brake cylinders 15 (Fig. 3, Fig. 4) of braking mechanisms 8. Each braking mechanism 8 stays deactivated when air feed line 5 is pressurized. Air feed line 5 has two controlled valves 6 connected to it for relieving pressure from air feed line 5. The power supply for controlled pressure relief valves 6 is also connected to controller 3. Controller 3 controls all electric motors 10 of the self-propelled vehicle equipment, as well as all its implements and attachments (not shown in the figures). Air feed line 5 in this example is also connected to brake assemblies 11 of self-propelled vehicle equipment as well as its implements and attachments.

The electric energy transmission circuit contains a block of circuit breakers 9. In this example, the block of circuit breakers is incorporated into the electric energy transmission circuit which is earthed. The availability of circuit breakers block 9 allows not only to turn on braking mechanisms 8 of drives 17 of self-propelled vehicle 1 , but also to switch off the power supply of electric motors 7 of drives 17, as well as electric motors 10 of all implements and attachments, thus enhancing the safety of human personnel riding the self-propelled vehicle.

Circuit breakers block 9 includes several push-button switches 12 connected in series and functioning as circuit breakers. Additionally, in-series emergency breakers 13 are also incorporated into the circuit. Push-button switches 12 can be mounted in control panel 30 on the body of self-propelled vehicle (Fig. 5) in places accessible for emergency braking. Emergency breakers 13 are built into safety devices, for example, safety guards (not shown in the figures), which can be installed, in particular, on seats 22 in the front and rear sections of self-propelled vehicle 1. Drive mechanism 14 (Fig. 2) includes transmission gear 19, as well as electric motor 7 and driven pulley 18 of belt drive 20 in the form of a hollow brake drum. Driven pulley 18 in this embodiment is connected to electric motor 7 with belt drive 20 through transmission gear 19. The inclusion of transmission gear 19 is necessary to coordinate the speed of engine 7 and driven pulley 18, and to prevent dangerous transmission overload at braking. Tensioning roller 21 imparts tension to the transmission gear. The rotation is transmitted from driven pulley 18 to driving wheel 16 of track drive 17 by means of driver shaft 24. Driven pulley 18 contains a brake drum in its cavity. The cavity of driven pulley 18 also houses the elements of a standard drum brake. The drum brake is controlled using tendon drive 23. Braking mechanism 8 includes (Fig. 3, Fig. 4) brake cylinder 15 with rod 25. Rod 25 is attached to lever 26, which can rotate around axis 27 and rests on return springs 28 installed in cups 29 mounted on frame 30 of self-propelled vehicle. Tendon drive 23 of braking mechanism 8 is attached to the lever.

The safety braking system operates as follows When one of push-button switches 12 is pressed or emergency breaker 13 is actuated, the electric energy transmission circuit connecting DC power supply 2 and commutator 3 is interrupted. In this case, controlled pressure relief valves 6 of air feed line 5 are activated. Rods 25 of brake cylinders 15 shift to another position, partly under the action of return springs 28. The movement of lever 26 acts upon tendon drive 23 of braking mechanism 8. The drum brake located in hollow driven pulley 18 gets activated and the self-propelled vehicle stops. The response of braking mechanisms 8 causes engines 7 to shut down, thus preventing possible overload of parts of drive mechanism 14.

A simultaneous inclusion of all auxiliary brakes 11 (TP1, TP2) alongside with the cutoff of power supply to engines 10 (MP1, MP2) of all implements and auxiliary /attached equipment is a factor of major importance.

INDUSTRIAL APPLICABILITY

The safety braking system is intended primarily for emergency stopping at an obstacle, or in situations hazardous to human personnel of the self-propelled agricultural machine. The system is the most efficient when used on self-propelled electrically driven track vehicles.