RU2292285C2 - Steering hydraulic booster with three-phase node of operation and spool mechanism with closed liquid circuit - Google Patents

Abstract

FIELD: automotive industry.

SUBSTANCE: spool mechanism of steering hydraulic booster has housing 5 with ports for drive tie-rods, spool unit 3 and oil channels 18. It is furnished also with lower oil ramp 4 with unions to let oil in and out, 17, 19, 20 and oil channels 18, upper oil ramp 2 with unions of oil main lines 34, 35 connected with chamber 16 of wheel turning power hydraulic cylinders 33 in which like channels group, joining unit 1 and spool unit 3 containing central shutter 6 coupled with steering shaft, follow-up shutter 7 coupled with drive lever from drag rod 28 of car steering mechanism and mode selector shutter 8 connected with selector drive, shutters being installed for turning. All three shutters are arranged in one plane. Spool mechanism provides one of three modes of wheel turning, namely, turning of wheels of front and rear axles to one side, turning of wheels in opposite sides or control of wheels of one front axle only. Steering hydraulic booster proper contains oil pump, spool mechanism indicated above, power hydraulic cylinders 33 installed on front and rear axles of car, oil main lines 34, 35 connecting oil pump with power hydraulic cylinders 33 through spool mechanism 30. Invention simplifies design of steering hydraulic booster and provides three modes of wheel turning, namely, turning of wheels of front and rear axles of car to one side, turning of wheels in opposite sides or control of wheels of one front axle only.

EFFECT: simplified design of steering hydraulic booster.

24 cl, 3 dwg

Description

The invention relates to the field of automotive industry.

A known electric power steering, in which to increase the force that is not surrendered from the steering column to the steered wheels, an electric motor is used, connected to the steering shaft by means of a worm gear, such as, for example, in the steering wheel "ECTIB STIRING" of BMW / magazine "Driving" No. 10, 2002 p. 68-70 /. The disadvantage of an electric amplifier is its low power, the delay in reactions to the actions of the driver.

The closest analogue of the proposed device is a hydraulic, power steering of a rotary type, in which to increase the force, a hydraulic system is used, including a hydraulic pump, a hydraulic power cylinder with a piston and a control device - a follow-up spool mechanism. Such an amplifier is installed, for example, on the latest modifications of the GAZ-3110 VOLGA car / Za Rulem magazine No. 9, 2003, p.124 /. Its disadvantage is the difficulty in installing it on the rear steering axle, associated with the need to control its spool mechanism from the driver's seat, the complexity of the device, the gear ratio of the steering mechanism, significantly exceeding one, which requires a large steering angle - around those revolutions.

The aim of the invention is to simplify the device power steering, as well as the ability to control the rear wheels in common mode and out of phase with the front.

This goal is achieved by using a separate arrangement of the spool device and power cylinders of the controlled axes, a closed circuit circuit of the hydraulic system, as well as using a spool mechanism with a gear ratio equal to or close to one.

Figure 1 shows a longitudinal section of the spool mechanism assembly.

Figure 2 is a longitudinal section of the gearbox spool gear.

Figure 3 - ramp of the oil pump / lower ramp / - section along aa.

Figure 4 - ramp of the main cylinder / upper ramp / - section along CC.

Figure 5 - position of the valves of the spool mechanism when the steering shaft is turned to the maximum angle / switch in common mode /.

Nor Fig.6 - the same, upon reaching the maximum angle of rotation of the wheels.

In Fig.7 - the same, when the steering wheel is returned to the middle position.

On Fig - the same, when the wheels return to the middle position.

In Fig.9 - the same when turning the steering shaft in the other direction by half the maximum angle.

Figure 10 - the same, when aligning the angles of rotation of the wheels and the steering shaft.

11 - the position of the valves of the spool mechanism when the steering shaft is turned to the maximum angle / switch in antiphase mode /.

On Fig - the same, upon reaching the maximum angle of rotation of the wheels.

On Fig - the same, when the steering wheel returns to the middle position.

On Fig - the same, when the wheels return to the middle position.

On Fig - the same, when you turn the steering shaft in the other direction by half the maximum angle.

In Fig.16 - the same, when aligning the angles of rotation of the wheels and the steering shaft.

On Fig - position of the valves of the spool mechanism in the control mode of one axis and the middle position of the steering shaft.

On Fig - the same, when you turn the steering shaft in any direction at any angle.

On Fig - scheme of the rotary mechanism in common mode - movement to the right "crab".

In Fig.20 - the same, in antiphase mode - side to the right.

On Fig - diagram of the stand for calibration of the channels of the spool mechanism.

On Fig - multi-channel die with round holes.

The power steering with three-phase operation contains two power cylinders, one for each axis, and a follow-up spool mechanism with central-axial movement of the shutters / valves /.

The spool mechanism assembly / Fig. 1/ consists of a docking assembly 1, an upper ramp 2, a spool assembly itself with a shutter mechanism 3, a lower oil ram 4. A spool assembly 3 comprises a housing 5 in which a central shutter 6 is mounted for rotation, damper 7, damper switch mode of operation 8 with an electromagnetic actuator, as well as two calibrated dies - upper 9 and lower 10.

There are two windows in the case 5: 11 - for connecting the follower flap 7 with the drive lever from the longitudinal link of the rotary mechanism and 12 - for connecting the switch flap 8 with the electromagnetic switch actuator. The docking unit 1 has a flange 15 for connecting to the gearbox and a central channel 14 for the spool axis. The upper ramp 2 also has a central channel 15 of the axis of the spool and, in addition, four chambers 16 with fittings 17 of the drain-supply of oil. The lower ramp 4 has six oil channels 18 and two fittings: supply 18 and drain 20 of oil.

The spool gear reducer / Fig. 2/ has a housing 22 in which bevel gears of the steering shaft 25 and the drive shaft 24 of the central shutter are rotatably located. The housing 22 also has a flange 25 for connection to the spool mechanism and mounting brackets 26.

The rotary mechanism of a fully-controlled car contains two lateral rods 27, two longitudinal rods 28, one of which is connected to the lever 29 of the drive servo damper 7; spool mechanism 30 with a mode switch; oil pump 31; steering gear 32; working cylinders of the front and rear axle 33; oil lines of pump 34 and slave cylinders 35.

Powered steering with three-phase operation as follows.

1st mode: in-phase operation of the rotary mechanism, the switch flap in position, as in Fig. 8. In this case, the pressure buildup in the chambers of the upper ramp 2 is compensated by the flow rate from the same cavities. The oil pump operates in bypass mode. The swivel mechanism is stationary. By turning the central damper to the maximum angle (Fig. 5/), the rarefaction circuit / -circuit / in the front cavity / a / of the first cylinder and rear cavity / g / of the second cylinder and the discharge circuit / + circuit / in the rear cavity / б / of the first cylinder and front cavity / in / second cylinder. There is a movement of the pistons of the working cylinders in one direction and the in-phase rotation of the wheels by the same angle of 30 °, set by turning the central damper by this angle. When aligning the values of the rotation angles of these shutters / Fig.6/, the channels of the first cylinder are blocked and the bypass channels of the second cylinder are connected, which leads to the stop of their pistons.

The movement of the central shutter in the opposite direction (Fig. 7/) leads to a change in the balance in the + and - circuits in the opposite direction and the tracking shutter moves after the central shutter until they occupy the middle position and the liquid balance is equalized to + and - circuits / Fig. 8/. Further rotation of the steering shaft in the same direction entails the movement of the second lobe of the central damper with the first position unchanged (Fig. 9/). The scheme of the spool mechanism in this case is similar to the above. In this case, the corresponding petal of the follower flap / Fig. 10/ is involved in the work. The steering shaft has a device that allows you to move the desired petal of the central shutter depending on the direction of rotation, and the petals themselves, thanks to the elastic connection with the shutter of the operating mode switch 3, can return to their original position after the exposure to them from the steering shaft, as well as changing the position afterwards after moving the shutter of the mode switch 8.

2nd mode: antiphase operation of the rotary mechanism, the shutter switch of the operating modes, as in Fig.14. Following its movement, the central 6 and tracking 7 flaps are also shifted with it in the same plane. The cavities / in / and / g / are switched on in the reverse order, the oil pump operates in bypass mode. By turning the central damper to the maximum angle (Fig. 11/), the vacuum circuit in the front cavity / a / of the first cylinder and in the front cavity / in / of the second cylinder is turned on, and the discharge circuit in the rear cavity / b / of the first cylinder and the rear cavity / g / second cylinder. Power cylinder pistons move in opposite directions. The rear and front wheels rotate in different directions. Further work of the spool mechanism is fully consistent with the above scheme / 12, 13, 14, 15, 16 /.

3rd mode: turning the front wheels with the rear wheels stationary, the shutter of the switch 8 in the position as in FIG. The oil lines of the rear power cylinder are closed, and its working circuit is transferred to the front cylinder in addition to the existing one, which leads to a doubling of its productivity, the oil pump operates in bypass mode. When the central damper is rotated, the fluid balance changes in twice the size / Fig. 18/. The folding mechanism is similar to the above, with the difference that the rear wheels remain stationary, and the angle of rotation of the front wheels changes twice as fast / Fig. 18/.

For correct operation of the spool mechanism, it is necessary to observe a strict correspondence between the areas of the outer ring / follower damper / follower damper / and the inner ring / central damper, as well as the cross section + and - of the ropes of the dies 9 and 10 of the spool unit. To calibrate the channels using the stand / Fig.21/. The liquid from the tank 36 is passed through the device 37 with the inside of the plate and is discharged into twenty-four beakers 38 by means of drain pipes 39. To ensure the uniformity of the fluid flow, the valve mechanism 40 is used. Comparing the fluid flow, a conclusion is made with the channel capacity. The channels of the spool mechanism of the same name: eight channels / a /, eight channels / b /, four channels / b /, four channels / g / are grouped in four chambers of the upper ramp / Fig. 4/. Each chamber has one fitting for connecting the tube of the working cylinder line - one for each cavity.

To simplify the manufacture of the spool mechanism, it is possible to drill twenty-four holes in the upper and lower dies according to the number of channels / Fig. 22/.

The oil pump is driven by an electric motor with a variable speed. Between the cavities of the working cylinders there is a bypass valve that opens when there is no loading of the on-board circuit.

Claims (5)

1. The spool mechanism of the vehicle’s power steering, comprising a housing (5) with windows for drive rods, a spool assembly (3) and oil channels (18), characterized in that it is equipped with a lower (4) oil ramp with oil supply and exhaust fittings ( 17, 19, 20) and oil channels (18), upper (2) oil ramp with oil line fittings (34, 35) connected to chambers (16) of power hydraulic cylinders (33) for turning the wheels of the car and in which the channels of the same name are grouped, docking unit (1) and spool unit (3) containing installed with the possibility of rotation, a central shutter (6) connected to the steering shaft, a follower shutter (7) connected to the drive lever from the longitudinal link (28) of the rotary mechanism of the vehicle, and a shutter (8) for switching operation modes associated with the switch drive, all three the shutters are in the same plane, while the pressure build-up in the chambers of the upper (2) oil ramp is compensated by the flow from these cavities in the bypass mode or the liquid balance changes when the central shutter (6) is rotated and its subsequent alignment when turning the tracking flap (7) by the same angle, and depending on the position of the flap (8) switching the operating modes, one of three modes of turning the car wheels is provided - turning the wheels of the front and rear axles of the car in one direction, turning in opposite directions or controlling wheels only front axle. 2. The spool mechanism (30) according to claim 1, characterized in that the central shutter (6) has petals connected in an elastic connection with the shutter (8) of the operating mode switch to allow returning to the initial position after the termination of the steering shaft and position changes following the movement of the shutter (8) switching operation modes. 3. The power steering of the car, comprising an oil pump, a spool mechanism (30), power cylinders (33) mounted on the front and rear axles of the car, oil lines (34, 35) connecting the oil pump to the power hydraulic cylinders (33) through the spool mechanism (30), characterized in that the spool mechanism (30) is made according to claim 1. 4. The hydraulic booster according to claim 3, characterized in that the oil pump is driven by an electric motor with a variable speed. 5. The hydraulic booster according to claim 3, characterized in that a bypass valve is installed between the cavities of the power hydraulic cylinders, which opens when there is no voltage on-board network.

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