SU1298102A1 - System for controlling wheeled vehicle differential locking - Google Patents

Abstract

This invention relates to mechanical engineering, in particular, to systems for locking the differential of traction wheeled vehicles. The purpose of the invention is to reduce fuel consumption by reducing the losses in the hydraulic drive of the locking clutch. The control system contains the steering booster 2, the steering wheel angle sensor 5, the pressure sensor 4, the differential with locking clutch 3, the solenoid valve comparing the device 8, the threshold device 14, the operating mode sensor 10, and b, associated with a locking clutch and with a drain, a differentiating chain 15, a one-oscillator 16, a device 13 for selecting an absolute signal magnitude, a logical element OR-HE9. The proposed system allows, in the differential lock operation modes, to connect the pressure source to the line interlock for a short period of time. 1 il. B (L 1CHE 00 U

Description

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This invention relates to automotive engineering, in particular to wheel tractor differential control systems.

The purpose of the invention is to reduce the consumption of tonnes by reducing losses in the hydraulic drive of the locking clutch.

The drawing shows an electro-hydraulic schematic diagram of a control system for locking the differential of a wheeled vehicle.

The automatic control system for locking the differential of the wheeled wheeled vehicle (Fig. 1) contains a three-position valve 1, a steering booster 2, a differential lock 3, a pressure sensor 4, a steering angle sensor 5, a steering wheel 7 comparing device 8, two-input logical element OR NOT 9, unit operation mode setpoint 10, power amplifiers .11 and 12, absolute signal size extractor 13, threshold device 14, differential 15 and a one-shot 16. A three-valve control valve is controlled by electro-magnets 17 and 18.

The system of automatic control of the differential lock of the wheeled vehicle operates as follows.

Using the setting device 10, the operation mode selects one of three possible modes of operation of the automatic control system: "Differential lock av-30me, i.e., the tomato is determined (the movable elements of the setpoint are in the upper position)," Differential blocking forced (movable elements setpoint knob are in the middle position) and "Differential blocking is off (moveable unit knob items are in the lower extreme position).

In the “Differential blocking” operating mode, the automatic setting device 10 connects the output of the threshold device 14 to the input of the differentiating chain 15, and the output of the OR-NOT 9 logic element through the power amplifier 11 with the electromagnet 17 of the three-way valve 1.

At the same time, in the case of straight-line movement and when the controlled wheels rotate by an angle less than the blocking angle (the angle of rotation of the controlled wheels, within which the differential is locked), a logical O signal is present at the output of the threshold device 14. The pressure in the locking collar 3 is recorded by a pressure sensor 4, the electrical output of which is proportional to this pressure. If this pressure is less than the required pressure defined by the threshold value IJon, then the output of the comparison device 8 is a logical signal "O, which affects the OR-NOT logic element. Logical output

of an element OR-HE 9 (l amplifier 11 power a solenoid 17 three-position divider 1 (there is no effect 18)) the nickname of the three-position bend in the leftmost position connects the hydraulic steering coupling. The pressure in the mu will grow and at the time more than required In device 8, the “1” and, correspondingly, the element ILINAL logical “Oh, h leads to the removal of the magnet 17 of the three-position divider I, the spool is at the average shutdown, the hydraulic pump of the coupling 3, the connection of the locking clutch remains with liquid tank and con t Ie, i.e., differential, and the maximum in the interlocking safety function of the three-position limiter 1. The time b to maintain the pressure (limits) depends on

positional hydraulic coupling 3 and at the accumulator of 7 vol. If the pressure in the couplings is more than specified, it is indicated. Thus, the automatic setting maintains the pressure limits at the tractor front, which ensures that the power of the power steering is controlled by turning the controllable to one or the other side of the angle sensor 5 to rotate or decrease the selection of the signal ab signal 13, it only forms to judge the conduct ( which allows the threshold device value) when the angle of rotation 50 becomes larger than the angle of the output of the threshold device, the logical signal is "1, a positive difference from but at the output of the differential 15 appears a short) signal, the forward one-shot amplification Itel 12 power with an electromagnet 18 t

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the element OR NOT 9 (logical "1) through the power amplifier 11 acts on the electromagnet 17 of the three-way valve 1 (no effect on the electromagnet 18) and takes the spool of the three-way valve 1 to the extreme left, i.e. the hydraulic pump of the steering booster is connected control 2 to locking clutch. The pressure in the clutch 3 begins to increase and at the moment when the pressure becomes greater than the required one, a logical signal "1 appears at the output of the comparator device 8 and, accordingly, the logical signal" O appears at the output of the logical element ORINE 9 leads to the removal of the influence from the electromagnet 17 of the three-position hydraulic distributor I, the spool of which occupies a middle position, i.e. the hydraulic pump from the locking clutch 3 is disconnected, it is connected to the drain and the locking clutch is locked . The pressure in the clutch is maintained by the actual squeezing capacity of the fluid and the design of the clutch itself, i.e. the differential remains interlocked. Moreover, the maximum overpressure in the blocking clutch is limited by the safety valve b and depends on the speed of the three-way valve 1. The blocking time (time to maintain the pressure in the clutch is within the specified limits) depends on leaks in the hydraulic leakage system in the three-way valve 1, the valve 3-rd and the device and the 3-way valve 3 and 3 meters. is significant. If the pressure in the clutch 3 becomes less than the specified one, then this process is repeated. Thus, the proposed automatic control system maintains the pressure in the coupling within the prescribed limits during the tractor's straight-line movement, which ensures rational use of the power of the hydraulic pump of the power-steering booster 2. During rotation of the steerable wheels of the steering wheel to one or another side, the output signal The rotation angle sensor 5 starts to increase or decrease. In this case, the absolute value selection device 13 generates a signal that allows judging only the rotation angle (which greatly simplifies the threshold device circuit) and at the time when the steer angle 0 of the steered wheels becomes greater than the blocking angle, the output of the threshold device 14, a logical ' 1 signal appears, i.e., a positive signal difference is obtained. Accordingly, a short (exponential) signal appears at the output of the differentiating chain 15, on the leading edge of which a one-shot is triggered, connected through the power amplifier 12 (if necessary) to the electromagnet 18 of the three-position hydraulic 5

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distribution distributor 1 and forming the signal of the required duration, providing full unlocking of the differential. At the same time, during the action of the one-vibrator 16, through the power amplifier 12 to the three-position hydraulic valve 1, the clutch 3 and the hydraulic pump of the hydraulic power steering 2 are connected to the drain, i.e., the three-way hydraulic control valve 1 is in the extreme right position, the differential is unlocked. After removing the control signal from the electromagnet 18 of the three-way control valve 1, the valve spool returns to its original middle position, i.e., despite the continued rotation, there is no effect on the valve. This makes it possible to significantly reduce the cost of hydraulic power to drive a three-way control valve 1.

In the “Differential Blocking” mode, the forcible moving elements of the operating mode setter take a middle position, i.e. the load resistor of the threshold device 14 closes to ground, which provides a logical “O” signal to the upper input of the logical element OR NOT and eliminates the effect on electromagnet 18 of a three-position control valve 1. Thereby, regardless of the angle of rotation of the controlled wheels, with the help of a comparison device 8, a logical element OR — NOT 9, an amplifier 1 1 power by exposing the three-position solenoid 17 Hydraulic distributor 1 is maintained in pressure b.lokirovochnoy sleeve 3. Moreover, for a given mode of operation is also typical pulsed pressure source connection to the coupling, ie. e. regular time gidrorul hydraulic pump is connected to the drain.

In the "Differential lock off" mode, when the proposed automatic control system is turned on, as well as switching the operating mode setter to this operating mode, a positive voltage drop is generated at the input of the single vibrator, which starts the single vibrator, which ultimately ensures unblocking of the differential signal from the electromagnetic three-position valve 1. In this mode of operation, the differential is unlocked, the hydraulic pump of the hydraulic booster the left control is connected to the drain, and the valve spool most of the time is in the middle position. Thus, the proposed automatic control system for locking the differential of the wheel mass means allows the Forced Differential Lock and Auto Differential Differential modes of operation to use the engine power efficiently, as it connects the pressure source to the clutch for a short period of time, and the rest time connects it with the drainage meter, which naturally reduces the energy losses due to the heating of the working fluid and affects the temperature conditions of the engine. As a rule, at the beginning of an agricultural operation with a wheeled tractor, the driver steers the car to a predetermined trajectory and when using such a system, the differential locks first, and then acceleration begins. The acceleration of the wheeled vehicle in the proposed control system does not affect the pressure in the lock-up clutch, which avoids the slipping of the friction elements of the lock-up clutch.

5 regardless of the engine speed and ensure a rational selection of power from the engine. In addition, the provision of a pulse control by an electromagnetic three-position valve 1 (the main time of the valve spool is in the middle position), allows the use of a valve with small leaks and small weight parameters. Such an automatic control system can also be used for all-wheel drive means.

Claims (1)

Invention Formula Wheeled vehicle differential lock control system 0 having a power steering, containing a steering angle sensor of the steered wheels, a differential lock up clutch, the control element of which is hydraulically controlled via a hydraulic distributor with solenoid valves 5 communicates with a source of pressure of the working medium, comparing the device, characterized in that, in order to reduce fuel consumption by reducing losses in the hydraulic drive of the locking clutch, it Q is equipped with an operating mode setter, made in the form of a switch with movable and fixed contacts, a pressure sensor, a hydroaccumulator, an OR-NOT two-input logic element, power amplifiers, a selection device 5 absolute magnitude of the signal, threshold device, differentiating chain, one-shot and safety valve, while the valve is three-way three-line, the first line of which is connected to the hydraulic accumulator, control block of the locking clutch, control valve cavity of the safety valve, through the safety valve the drain, as well as the input of the pressure sensor, the second line of the hydraulic distributor is communicated with the source of pressure of the working medium, and the third line is communicated with in the first position, the first line communicates with the second, during the second position of the second line communicates with the third, and the third position of the second line communicates with the first and third, while the solenoid control valves of the hydraulic converter are electrically connected to the outputs of power amplifiers, while the output of the pressure sensor is connected to one input of the comparison device, to the other input of which the voltage source corresponding to the threshold value, the output comparing with a Q contact, and the fourth stationary The main input is connected to the first input of a two-input logical element OR NOT, the other input of which is connected via a serially installed threshold device and the extraction device absolute contact is connected to the third moving contact, in the second position the first moving contact is connected to the second fixed contact, the second fixed contact to the second moving by contact. 5th stationary contact is connected to the tri-angle of rotation of the steered wheels, with the source moving contact, in the third position the third stationary contact is connected to the second moving contact, and power supply, as well as with the first moving contact, the first and second fixed contacts of the switch, the third fixed contact of which is connected to the moving contact, the sensor input to the power supply, the fourth and fifth non-rotation angle connected to the hydraulic booster, the moving contact is connected to the third the switch contacts are connected to the output of a two-input logic element OR NOT, the switch and the seventh contact are connected to ground, the second moving contact is through a differentiating chain, the one-shot is connected to the input of one power amplifier, the third moving contact is connected to the input of another power amplifier, while the first switch position the first fixed contact is connected to the second movable contact connected to the third movable contact, in the second position the first movable contact is connected to the second contact contact, the second fixed contact with the second moving contact.  the fifth fixed contact is connected to the third movable contact; in the third position, the third fixed contact is connected to the second movable contact, and  a moving contact, the input of the angle of rotation sensor being connected to the hydraulic booster by means of a rudder-moving contact connected to left control.