SU1281450A1 - Control system for vehicle transmission - Google Patents

Abstract

The vehicle hydrostatic transmission control system relates to vehicle engineering. The aim of the invention is to increase reliability in operation. The control system contains a reversible variable pump 1, an unregulated motor 2 interconnected by pipes 3 and 4. The pressure source 7 is connected to the gear lockout mechanism 5 and the actuating cylinders 18 and 19 of the high pressure safety valves 20 and 21. The pressure source 7 is kinematically connected control pedal 11. The overflow valve 3 is installed coaxially with the high-pressure safety valve 20, while the cavity of the latter is connected to the pipeline 3. Depending on the direction of movement for heating The corresponding safety valve is narrower, which increases reliability in operation. 1 hp ff, 3 ill. at

Description

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This invention relates to a transport engineering industry and is intended to control a reversible hydrostatic transmission by interrupting a power flow passing through a hydrotransmission under emergency braking, gear shifting and fast reverse.

The purpose of the invention is to improve the reliability of work.

Figure 1 shows a schematic diagram of a hydrostatic transmission; figure 2 - valve block with forward control, section; on fig.Z - the same, without driving forward.

The vehicle's hydrostatic transmission control system contains reversible adjustable power 1 (figure 1), driven by the engine. What is internal combustion (not shown), and unregulated motor 2, interconnected by pipelines 3 and 4 and forming a closed power circuit. Motor 2 is mounted on a stepped gearbox (not shown) equipped with gear locking mechanism 5 (ranges), which is connected to the pressure source 7 by the conduit 6, and the pipeline 8 to the reservoir 9 and through the lever 10 - with the lock pedal 11, pressed against the deck 12 of the driver’s pad by the spring 13.

In addition, the pressure source 7 is connected in parallel by pipelines 6, 14-16 by means of a single-sided choke 17 with an actuator, IlJ cylinders 18 and 19 for controlling high-pressure safety valves 20 and 21.

The actuating cylinders 18 and 19 are embedded in the housings 22 and 23 of the safety valves 20 and 21 and consist of the sleeves 24 and 25, 26 and 27, pressed against the walls of the sleeves 24 and 25 by springs 28 and 29 (figure 2). Springs 32 and 33 of locking elements 34 and 35 of safety valves 20 and 21, which are made coaxially with overflow valves 36 and 37 in housings 22 and 23, rest on the end surfaces of the rods 30 and 31 through adjusting valves (not shown). Locking elements 34 and 35 are connected to hydraulic lines 3 and 4 of the power circuit, axial bores 38 and 39, discharge holes in pistons 40 and 41 overflow valves 36 and 37, internal channels 42 and 43.

In addition, the openings 44 and 45 are provided in the housings 22 and 23. The passage of the working fluid when the overflow valves 36 and 37 are opened and the nopi-ni 40 and 41 are permanently closed using springs 46 and 47. Valves 48 and 49 are safety valves. 20 and 21 are connected to hydraulic lines 3 and 4 by internal channels 42 and 43 and openings 50 and 51 in housings 22 and 23.

When using hydrostatic transmissions, infinitely variable transmission speeds are used instead of

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body cylinders 18 and 19 (figures 1 and 2) are installed plugs 52 and 53 (fig.Z).

The control system operates as follows.

In the static position, the pedal 1 1 is pressed by the spring 13 to the floor 12, the pipes 6, 14-16, the pressure source 7, the flow cavities of the actuating cylinders 18 and 19 are connected through a pipe 8 to the reservoir 9. The springs 28 and 29 press the pistons 26 and 27 to the walls of the sleeves 24 and 25, and 1PTOCI 30 and 31 compress the springs 32 and 33 through adjusting washers and force the locking elements 34 and 35 against pressure.

Depending on the direction of movement of the vehicle, the corresponding safety valve is also under load. For example, when moving forward under load, the safety valve is located. 1 Pan 20. At this time, the flow of working fluid under pressure is supplied through pipeline 3 and the internal channel 42 to the piston 40 of the relief valve 36, through the opening 38 in the piston 40 the pressure goes to the locking element 34 of the safety valve 20. Since the pressure in front of the piston 40 and behind it is the same, the spring 46 presses the piston to the right extreme position, in which the opening 44 is closed and the entire flow of working fluid is directed to the motor 2.

At the same time, the working fluid under pressure flows from the pipe 3 through the internal channel 42 through the opening 51 of the safety valve 21, the locking element 35 to the socket, and the rod 31 with the piston 27 moves to its extreme position.

When the pressure rises to the setting of the safety valve 20, the zipor element 34 opens, compressing the spring 32. and through the opening 50 is directed into the pipe 4 through the internal channel 43. at the same time HOpnieHb 40 due to the pressure difference in front of the piston and moves to the left end position, compressing the spring 46 and opening the opening 44 in the housing 22, and the liquid flows into the suction pipe 4 until the pressure drops below the setting of the safety valve. With this, the vehicle stops.

When the vehicle is stopped with the gear engaged, the gear teeth, which are engaged in the gearbox, are pressed to each other with great effort due to the unevenness of the road profile or the floor, as well as the motor operation in the pump mode from the vehicle mass. In this case, the gear shift is difficult or impossible.

To shift gears (Figures 1 and 2), you must simultaneously press the pedal 11 of the gear-lock mechanism 5 and the brake pedal (not shown), while the brake fluid from the pressure source 7 is 10

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is given to the drive of the locking mechanism 5 and to the executive cylinders 18 and 19 through pipelines 6, 14-16 through a one-way throttle 17. Porschni 26 and 27 with rods 30 or 31 of the executive cylinders 18 or 19 (depending on the direction of the load from the vehicle weight ) move to the left or right extreme position respectively, compressing the spring 28 or 29 and relieving the load from the springs 32 or 33 of the locking elements 34 or 35. The latter opens under the action of an external load, forming a flow of working fluid from the high pressure zone to the zone low pressure is similar to the operation of a safety valve when it is triggered in case of exceeding the remote setting. The load is reduced to a value that allows gear shifting. After the gears are shifted, the pedal 11 spring 13 returns to its original position as far as it will go to the flooring 12, the lever 10 moves the plenum of the pressure source 7 to the position opening the working fluid to the reservoir 9. Under the action of springs 28 or 29 wheels 26 or 27 moving, respectively, to the right or left extreme positions with the rods 30 or 31, smoothly compressing 25 the spring 32 or 33 of the locking elements 34 or 35 before closing them. The flow of working fluid is stopped from the high pressure zone to the low pressure zone. After shifting gears by shifting the manual transmission control lever, for example, "Forward the vehicle begins to move."

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Claims (2)

1. A hydrostatic transmission control system of a vehicle, comprising a closed power circuit comprising a hydraulic pump connected by hydrolines and a hydraulic motor with built-in overflow valves for forward and reverse, and a device for forced breakdown. ten )five 20 25 thirty 35 40 power flow with a safety valve including a spring-loaded shut-off element installed in the housing, each of the overflow valves including a housing with a spring-loaded shut-off element installed in it, and the dumped cavity of each overflow valve is connected to the corresponding power line hydroline, which that, in order to increase reliability in operation, it is equipped with an additional safety valve with a spring-loaded shut-off element, with the corresponding overhead The drilling and safety valves are installed coaxially, each of the safety valves is spring-loaded towards the overflow valve, and the shut-off element is designed to connect the safety and overflow valves, each safety valve being connected hydraulically to the power line through the holes in the housing. 2. The system of claim 1, characterized in that, in order to increase the reliability of the transmission, which has a stepped gearbox with a hydraulic transmission locking mechanism, it is additionally equipped with a control pedal, actuating hydraulic cylinders of safety valves and an adjustable throttle, while the actuators the safety cylinders of the safety valves are installed coaxially with the latter, the spring of the executive hydraulic cylinder is installed in the brushless-free cavity, and the safety spring is connected with the piston rod paw schtoko- stems cavity relief cylinders to:. 1apanov interconnected and through hydraulic locking mechanism - hydraulic line to the hydraulic tank in which is installed an adjustable throttle between the connecting point and hydraulic valves, wherein the control pedal is kinematically coupled to the latter. 11 I I. . 36 6 f / f /} 38 23S 1 ffS 37 ft 5222 23 33