SU1414668A1 - Positive-displacement hydraulic steering gear with differential gear locking - Google Patents

Abstract

And: the invention relates to automotive and tractor engineering and concerns cross-axle differentials and steering of wheeled machines. The purpose of the invention is to expand the functionality by ensuring the constancy of the blocking angle. The device includes an engine speed sensor, two pressure sensors, one of which registers the pressure in the locking clutch and the other in the hydraulic accumulator, the angle of rotation of the steering wheels and the electronic unit also connected to the electrical equipment of the wheeled machine. Three-way solenoid valves are used as actuators, one of which is two-way and the other three-way. When starting the engine, the electrical equipment receives a signal to the electronic unit, which generates a short control signal that ensures that the position of the spool of the two-way valve, at which the hydraulic pump is connected to the drain. This automatic system impulsively connects the pump to the hydraulic accumulator and the locking clutch, i.e. rational use of pump power. At large angles of rotation of the device automatically connects the locking clutch to the drain and unlocks the differential. 1 il. W with 4ib 4 F a 00

Description

The invention relates to automotive and tractor engineering and relates to wheel-to-wheel differentials and steering of wheeled machines.

The aim of the invention is to enhance the functionality by ensuring the constancy of the blocking angle,

The drawing shows a functional diagram of a hydrovolume steering with a differential locking mechanism.

The proposed device includes a steering mechanism 1, a valve block 2, a metering pump 3, a check valve 4, a pump-motor 5, a check valve 6, a safety valve 7, a gear pump 8, a safety valve 9, the first two-position three-line solenoid valve 10, hydroaccumulator 11, first pressure sensor 12, check valve 13, second three-position solenoid valve 14, lockout coupling 15, second pressure sensor 16, rotation angle, rectifier 18 first threshold device 19, mode sensor 20 work, sensor 21 equipments from the engine, the second threshold device 22, the second logical element is NOT 23, the second logical element is 2I 24, the first one-vibrator, 25, the second one-vibrator 26, the second logical element 2ILI, 27, the first logical element NO 28, the first logical element 2IL 29, the first logical element 2I 30, the third power amplifier 31, the fourth Wuxi. power amplifier 32, second comparing device 33, third one-oscillator 34, analog divider 35, analog multiplexer 36, first comparing device 37, logical element ZI 38, power amplifiers 39 and 40,

Hydraulic steering with differential locking mechanism works as follows.

When the engine is working, the oil from the gear pump 8 goes to the metering pump 3 and from it to the solenoid valve 10. If the pressure in the hydroaccumulator 11 is less than the required one, i.e. the signal from the pressure sensor 12 is less than the reference value + Ugn, then the output second comparing device 33 presence

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signal of logical 1, which acts on one input of the second logical element 2I 24. since the engine speed is not close to zero, the signal of logical O is present at the output of second threshold device 22, and the signal of logical 1 Thus, the output of the logic element 2 and 24 is also present signal logical 1, which acts through the logical element

2ILI27 to the input of the logic element 2И 30. Since the engine does not start, then the input of the one-vibrator 25 and the logical element HE 28 contains a logical O signal, and the output of the logical element HE 28 is respectively a logical 1 signal, which ensures that incoming the signal from the output of the logic element 2ILI 27 to the amplifier 32 power. The power amplifier 32 acts on the solenoid of the solenoid 10, which eventually causes the valve spool to move and the metering pump 3 communicates with the hydraulic accumulator 11. As a result, the pressure in the hydraulic accumulator 11 starts to increase, respectively, the pressure sensor signal also begins to increase. At the moment of time when this signal becomes slightly larger than the reference value + U, the output of the comparator device 33

A logical I signal appears.

(i.e., a negative voltage drop), A one-shot 34 is triggered by a negative voltage drop, which generates a signal of the required duration, which acts through the logic element 2IL or 29 on the power amplifier 31. The latter acts on the solenoid valve 10, which separates the hydroaccumulator 11 with the metering pump 3 and informs the latter with the hydraulic tank. At the same time, mainly the hydraulic pump B consumes only the power for pumping working fluid (there is no steering wheel) dispenser and hydraulic tank. If, as a result of leaks or the connection of the locking clutch 15 to the hydraulic accumulator 11, the pressure becomes somewhat less than the required one, then the description process repeats.

When turning the steering wheel, the spool of the metering pump 3 is displaced, providing oil supply to the power cylinder of the steering mechanism 1 in an amount proportional to the angle of rotation of the steering wheel.

When the engine speed is close to zero, at the output of the threshold ostree, the metering pump 3 with gydrobakom. . In this case, the output of the logical element HE 28 contains a signal of logical O, which, through logic elements 30 and 38, prohibits the flow of control signals to pressurize the hydraulic accumulator 11 and the coupling 15. Thus,

In logic 22, a logic start signal appears.

It is 1 (positive differential), and the output of the logical element NOT 23 is a signal of logical O, which prohibits the effect of the comparison device 33 on the power amplifier 32 at pressures lower than the required one. According to a positive differential at the output of the threshold device 22, a one-shot 26 is activated, which acts through logic 20 element 2ILI27 on a logic element whose second input contains an enable signal — logic 1. The last element 30 acts through valve 32, which provides connection of hydroaccumulators torus 11 to hydrostatic steering. This ensures that

Mode selector 20 enables three modes of differential operation. Differential locking and Digital locking disabled.

In operation mode, the Automatic Block

unit element on average position of the threshold device for analog multiplex element ZI 38

In this case, the sensor is 17–25 (for example, the potentiometer gives a signal proportional to the turn, the sign of which is the direction of the turn (n or left turn).

pressure in the control system with no 30 signal, the value of which is a working diesel, which facilitates the process of controlling the tractor. As the pressure in the hydroaccumulator 11 decreases, due to leaks to a value less than the pressure in the coupling 15, the check valve 13 opens, which allows a longer time to maintain the pressure in the device with the engine off. Since this automatic control system is characterized by the impulse connection of the hydraulic pump 8 through the metering pump 3 to the hydraulic accumulator, i.e. power costs are insignificant, the division in the hydroaccumulator 1t can be chosen equal to or slightly greater than the pressure in the clutch 15, which is economically justified.

When the engine is started, simultaneously with the turn of the ignition lock, a logical 1 signal is sent to the single vibrator 25 and the NOT 28 logic element. One positive vibrator 25 is triggered by this positive differential, which through the logic element 2ILI 29 and the power amplifier 31 acts jHa electrovalve 10, which ensures pump post in che

Unit 20 mode of operation provides three modes of operation. Differential blocking is automatic, Differential blocking is forced and Differential blocking is disabled.

In the operation mode, the Differential Lock is automatic (

The master unit is in the middle position. The signal from the output of the threshold device 19 is fed to the analog multiplexer 36 and the logical element ZI 38.

In this case, the angle sensor 17 (e.g., potentiometric) generates a signal proportional to the angle of rotation, the sign of which determines the direction of rotation (right turn or left turn). Straightener 18

It is proportional only to the angle of rotation and does not depend on the direction of rotation to the threshold device 19. At the same time, at the output of the threshold device

g 19 there is a signal of logical 1, if the angle of rotation of the guide wheels is less than the blocking angle. If the angles of rotation are greater than the blocking angle, the output of the threshold device 19 has a logical O signal. The blocking angle is determined by the threshold device 19. In a straight-line motion. the wheel-drive control signal of the logical t of the threshold device 19 affects the analog multiplexer 36 and logic element 38. This provides connection to the output of the analog multiplexer 36, a signal present at input x1. If the pressure in the clutch 15, recorded by the pressure sensor 16, is less than the required pressure, which is set by the signal present at the non-inverted input of the lower comparator of the comparison device 37, then the lower comparator operates and operates through the logic element 38, amplifier 4fi

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power to the valve 14, and he connects the clutch to the hydraulic accumulator 11, as a result of which the pressure in the clutch begins to increase. At the time when the signal from sensor 16 becomes larger than the signal present at the inverter input of the lower comparator of the comparison device 37, the influence from logic element 38 and power amplifier 40 is removed, which ultimately results in locking the slide valve 14 . The pressure in the clutch is limited from above by the value present on the non-inverting input of the upper comparator of the comparison device 37, and from below by the value present on the non-inverting input of the lower comparator of the device 37. When turning the steering wheels of the vehicle by an angle greater than the blocking angle at the output of the threshold 37 device 19, a logical O signal appears, which prohibits, through element 38, the arrival of a control signal for pressure injection. At the same time, a logical O signal is applied to the analog multiplexer 36, which connects to its output a signal present at the x2 input and specifies the pressure at which the differential is unlocked. As a result, the upper comparator of the comparator device 37 operates and acts through the power amplifier 39 on the solenoid 14, which in turn communicates a coupling with a drain. When the pressure in the coupling becomes less than the value specified by the signal at the non-inverting input of the upper comparator of the device 37, the latter removes the impact from the valve 14 through the power amplifier 39.

In the operating mode Differential blocking, the forced movable element of the setter 20 is in the lower position and the device does not differ from the operating mode. The differential blocking is automatic at angles of rotation smaller than the blocking angle. Moreover, the pressure in the clutch is maintained within the specified limits regardless of the angle of rotation of the guide wheels.

In the operation mode Differential lock, the movable element of the setting device 20 is in the upper position and the operation of the automatic system does not differ from the operating mode. The differential lock is automatically at angles of rotation greater than the block angle.

Claims (1)

Invention Formula Hydraulic steering with locking mechanism di (1) Erenzia a la containing a metering pump with a valve block, a steering mechanism, a diesel-driven pump, hydraulic tank, hydraulic accumulator, pipelines, electrical equipment, a differential lock distributor mounted on a bracket under the instrument panel and kinematically connected to the handle located in the cab lock valve located in the hydraulic actuating steering actuator, a lock-up clutch mounted on the rear axle housing, characterized in that, in order to expand Functional capabilities by providing a constant blocking angle, it is equipped with a check valve, a rotation angle sensor, two pressure sensors, an engine speed sensor, two solenoid controlled valves, one of which is two-position, three-line and hydraulically connected to one line with a metering pump and a safety valve, the second one with a hydraulic tank, and the third one with a hydraulic accumulator, the first pressure sensor, the first line of the second distributor, made three-way, three-way, and through a check valve with a lock-up clutch, a second pressure sensor and a second line of a second solenoid valve, a third line of which is connected to a hydraulic tank, a divider, an analog multiplexer, whose information inputs are connected to two divider outputs, the first comparator device, connected with one of its inputs with the third output of the divider, the second input with the output of the analog multiplexer and the third input with the second pressure sensor, the second .-