JPS6085063A - Steering device for vehicles - Google Patents

Abstract

PURPOSE:To make a front-wheel power steering device and a rear-wheel steering device both so as not to interact each other and thereby operate them with certainty, by distributing and feeding these devices with a fluid being discharged out of a pump through a flow dividing valve. CONSTITUTION:When steering force to be added to a steering wheel 19 grows large, in a first control valve 32, variable orifices 32b and 32d are throttled down in a manner conformable to the steering force and simultaneously other variable orifices 32a and 32c are opened whereby a high pressure fluid is fed to a fluid chamber 38 of a power cylinder 34. Then, this power cylinder 34 produces steering assist force, forcibly pressing a rack 16, thus the steering force of the steering wheel 19 is relieved to a degree. In addition, in a second control valve 33, a flow passage area of each of variable orifices 33a-33d is largely varied whereby a high pressure fluid is fed to each of actuators 40b and 40d, making a deviating angle in rear wheels larger. With this constitution, the flow of a pressure fluid to be fed to each of control valves 32 and 33 is secured to have the specified quantity commensurate to a flow dividing ratio owing to a flow dividing valve 31.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technology Field 1) This invention is a vehicle steering system, and an ivt steering system is a power steering mechanism that assists the steering of the front wheels by the action of pressure fluid, and a power steering mechanism that assists the steering of the front wheels by the action of the IF power fluid. This invention relates to a rear wheel steering device that performs steering, and a steering device that distributes and supplies pressure fluid generated by two pressure fluid generating means using a flow divider valve.

(Prior Art) For vehicles in recent years, steering devices capable of steering both front wheels and rear wheels have been proposed for the purpose of improving turning performance. Conventionally, this type of steering device has been disclosed, for example, in Japanese Patent Application Laid-Open No. 57-9! A compliance steer control device described in Japanese Patent No. 1470 is known.

This compliance steer control device is equipped with a hydraulic actuating means (4) (installed in an elastic body interposed between the suspension device of the rear wheel and the cap), and the hydraulic actuating means is connected to the bassore ring of the power steering mechanism. By supplying it+If of i?, jK, control is performed to reduce or avoid increasing the compli-i'unsteer-j' which occurs when the vehicle is traveling on both circumferences 13.

However, the compliance steering is increased 1: 4) The second is to increase the rear wheel (￥￥ rudder II).

When the steering wheel is turned, the control device steers the rear wheels in the same direction as the front wheels and sets the turning characteristics to the understeer side. n: Aims to improve turning performance when driving at high speed.

As is well known, the power steering mechanism controls the steering assist force generated by the power cylinder so that it becomes smaller in the high vehicle speed range in order to give the driver an appropriate steering feel. In addition, a region (insensitive'!:'j) is set in which the power cylinder does not produce a steering assist force within a range where the applied steering force is minute.

Therefore, low pressure /llI field is supplied to the power cylinder of the power steering mechanism at 101 vehicle speed, and when the steering force applied to the steering wheel is very small, the power cylinder of the power steering mechanism is supplied with 1 bar. Not done.

However, in controlling the rear wheel's pre-emption steering, it is more stable than 7, but in order to achieve cornering, it is 10.
In the H and lL speed ranges, it is desirable to have a large compliance steer and a large deflection of the rear wheels. It is desirable to bias the rear wheels even if the steering force applied to the rear wheels is very small. For this reason,
5. If the hydraulic actuation means of the compliance steer control device supplies hydraulic pressure to the power cylinder of the power steering mechanism, it is not possible to control the compliance steer control device with the best characteristics in terms of cornering performance.
! It is necessary to control the hydraulic pressure supplied to the power steering mechanism separately from the hydraulic pressure supplied to the power cylinder of the power steering mechanism.

However, the control valve used in the above-mentioned power steering mechanism and compliance steering control device and which controls 1 ton of oil in response to the steering handle is such that the pump discharges water when the energized steering handle is in the middle position. A control valve of the type (center open) that recirculates the pressurized oil is used.For this reason, the control valve of the power steering mechanism and the compliance steer control, which have different initial operating characteristics as described above, are used. i1i control of equipment
i) If pressure oil is supplied from the pump 111-, there is a problem that the desired 01 characteristics cannot be obtained. In a steering system in which a dead zone is set for light, when the steering force applied to the 1ffi steering wheel is very small, the hydraulic actuating means of the 2J power steering control device
＼When 1 liter is supplied by the control valve, the hydraulic circuit resistance on the compliance steering control device side increases, so the pressure oil discharged by the pump is returned to the reservoir through the control valve of the power steering mechanism, and is returned to the 2 liter tank. - Sufficient hydraulic pressure is not supplied to the hydraulic actuation means of the C unsteer control device.

(Object of the Invention) This invention was made in view of the problems mentioned in L, and has the best features 111. control] and the rll- pump (baso steering link system) and rear wheel steering system.
The purpose of this system is to supply pressurized fluid without \support+i<f/-1i and to reduce the size of the rudder device and the manufacturing cost.

(Structure of the Invention) A steering device for a vehicle according to a first invention includes a steering gear mechanism that transmits steering force applied to a steering wheel to a front wheel and biases the front wheel, and a steering gear mechanism that pressurizes fluid in a reservoir. a pressure fluid generation means for generating pressure fluid; two control valves for controlling the pressure fluid generated by the pressure fluid generation means in response to the steering of the steering wheel; - A power cylinder that is supplied with pressure fluid controlled by one of the control valves and generates an auxiliary force that biases the front wheels, and an actuator that is supplied with pressure fluid that is controlled by the other of the control valves and biases the rear wheels. In the steering system of the vehicle, the pressure fluid generated by the pressure fluid generation means is distributed between the two control valves (iii) and supplied at a predetermined division ratio.

Further, the vehicle steering device according to the second invention includes a steering gear mechanism that transmits the steering force applied to the steering wheel to the front wheels and biases the front wheels, and a steering gear mechanism that pressurizes the fluid in the reservoir (11 Force fluid two control valves that control the pressure fluid generated by the pressure fluid generation means in response to the steering of the steering handle, and a pressure fluid controlled by one of the control valves; A steering system for 41 cars equipped with a power cylinder that is supplied with a compensating force to bias the front wheels, and an actuator that is supplied with pressure fluid controlled by the other control valve to bias the rear wheels. a dividing valve which distributes and supplies the pressure fluid generated by the pressure fluid generation means to the two control valves at a predetermined division ratio; and a pressure fluid which is supplied from the 51 flow valve to the one control valve. or 111, No. 53, a bypass passage that returns at least one of the pressure fluids supplied from the flow valve to the reservoir, and a flow rate of the pressure fluid that returns to the reservoir via the bypasses 1 to 8. Control 1al
It is equipped with a flow control valve to control the flow rate.

According to the vehicle steering system according to the first aspect of the invention, the flow rate of the power fluid supplied to each control valve is maintained by the branch valve, so that each control valve can be independently controlled. For example, even if only the actuator that deflects the rear wheels is operated without operating the front power cylinder, sufficient pressure fluid is supplied to this actuator to steer the rear wheels. It is possible to reliably deviate in accordance with the steering of the half wheel.

Further, according to the vehicle steering device according to the second invention, similarly to the vehicle steering device according to the first invention, it is possible to reliably bias the rear wheels in response to the steering of the steering wheel, and further, By controlling the pressure fluid that flows back through the bypass path using a flow control valve, it is possible to obtain arbitrary steering characteristics. Of course, by controlling the flow rate of the single-force fluid flowing through the bypass path according to, for example, the vehicle speed, it is possible to set characteristics that depend on the vehicle speed in the steering system of this vehicle. If the flow rate of the pressure fluid flowing through the steering system can be changed by manual operation, the steering characteristics can be set to the desired characteristics of the driving vehicle or the characteristics optimal for the vehicle to which the steering device is installed. With H, the number of tasks increases.

(Embodiments) Hereinafter, embodiments of the first invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an eleventh embodiment of the first invention,
The outline of the vehicle steering system is shown below.

First, to explain the configuration, 11 is a heavy body, 121 (, 12
L is the front wheel, 131 inches, 131. indicates the rear axis.

Front axle 12R1121, 4J, respectively, 14R1+4L and side F' 1: I y P
'151, 15[, end of rank 16 (41
,X/, are connected. Binion 17 on rack 16
are in mesh with each other, and the pinion 17 is connected to the steering wheel 19 via the steering shaft 1 river 8. The car rack 16 and the pinion 17 constitute a steering gear mechanism 20.

Rear wheel 131? , 13I, are each semi-sealing arm 201.211. The rear wheel is dynamically supported by the suspension member 22 through the rear wheel.

Both ends of the rear wheel suspension shaft 22 are connected to the bin 241 through the insulator rubber 2317.2:3L. ,
24L, and is elastically supported by the vehicle body 11, and the differential gear housing δ is fixed by bolts (not shown). This differential gear housing 25 is also elastically supported to the vehicle body 11 by a pin 27 via an insulator rubber 26. Furthermore, 28I? , 2B+, the differential gear in the differential gear ring 25 and the rear wheel 131
≧, 131. This is the drive shaft that connects the

29 is a pump (pressure fluid generating means) that pressurizes and discharges the working fluid in the reservoir 30, and the discharge boat of the pump 29 is connected to the inlet boat of the diversion valve 31 via piping 1) 1. .

The flow dividing valve 31 is a well-known one, and the two
The throat boat is connected to stay 1 by piping 1'7+P).
It is connected to a first control valve 32 and a second control valve 33 numbered on the ring shaft 1B, and distributes and supplies the pressure fluid discharged by the pump 29 at a predetermined division ratio.

The first control valve 32 is connected to the reservoir 30 through piping P8, and is also connected to the power cylinder 34 numbered on the rack 16 through piping P'4%P5, and is supplied from the diversion valve 31. Handle 1 for steering pressure fluid
9 (in the embodiment, the steering force applied to the steering wheel 19), the control fffll L is supplied to the power cylinder 34. However, this first control valve 32 is
Four 11 variable orifices 32a, 32b, 3 whose flow path area changes according to the steering force applied to the steering handle 19
2 C, 32rl to the right, the 1iJ modified orifice 32
Pressure fluid is controlled by a, ,'(2b, 32(1,:32d). The power cylinder 34 has a piston 36 fixed to the sink 16 that can freely move 1n into the cylinder body 35 provided in the 111 body H. Fitted into two fluid chambers 3
7.3B is defined. The power cylinder 34 generates a rudder assisting force corresponding to the difference in power between the fluid chambers 37 and 311 to press the rack Ili. These pumps 29,
Reservoir 30, first control valve 32 and power cylinder 3
4 constitutes a well-known power steering device 39.

The second control valve 33 is connected to four actuators 40a, 40b, 40C140d that are interposed between the rear wheel suspension member 22 and the vehicle body 11 through pipes 1), , l), .
It is also connected to the reservoir 3rd via piping P9. This second control valve 33 is also similar to the first control valve 32 described above.
Similarly, four variable orifices 33a whose flow path area changes in response to the steering force applied to the steering wheel 19;
33b, 33c, and 33d, and each actuator 40a, 40+1 controls the pressure fluid supplied from the diverter valve 31 according to the steering force applied to the steering handle 19.
．． Supply to 40C140d. Actuator 4[)a
, 40b, 40c, and 40d are connected to the vehicle body II and the rear wheel suspension member 22 by a heavy binding joint, and the insulator rubber 23R1231 is deformed by the action of the pressure fluid supplied from the second control valve 33, so that the rear wheel suspension member 22 is bent. 27 'c Rotate around the center. That is, the actuator 40
a, 4Qb, 40c, 40d are rear wheels <7
By rotating Sea + 7 member 22, rear wheel +3R
, I3L is biased. These pump 29, reservoir 3o, second control valve 33 and active, eta 40a,
40b and 40C240d are Comply-1' steering system fall '9. (rear axle steering device) 4 (consists of this compliance steer; til control device 41 is described in detail in Japanese Patent Application Laid-Open No. 57-99470, 8.
Since it is stated in 111, the theory 1y1 will be omitted hereafter.

Next, the effect will be explained.

The steering system of this vehicle includes front wheels 12R112 and rear wheels 131 of the vehicle. , +31. The power steering device 39 generates a steering assist force to steer the front wheels +2R3+2L.
The steering wheel I9 assists the steering wheel I9, and the compliance steering control device 41 biases the rear wheel 13R113I- in the same direction as the front wheel +2R112L in response to the steering of the steering wheel I9. When the steering force applied to the power steering device steering handle 19 is small, a dead zone 41, ζ is set in which no steering assist force is applied.

Now, when the steering wheel circle is not steered by IS1, the respective first control valves 32 and second control valves 33 are connected to the respective variable orifices 32a, 32b, 32C132d.
and variable orifices 33a, 33b, 33c, 33d
have the same opening degree, the pressure fluid discharged by the pump 29 is distributed to each control valve 32.33 by the flow dividing valve 31, and then flows through each control valve 32.33 to the reservoir 30.
It is flowing back to.

Here, when a slight steering force (within a dead zone) is applied to the steering handle 19 (for example, a force for steering to the right, the same applies in the following description), the second control valve 33 opens its variable orifice 33a, 33c is narrowed in response to the steering force, and the variable orifice 33b3d is opened in response to the steering force, or a dead zone is set in the power steering device 39. The opening degrees of 32b, 32+, and 32d change. Therefore, the pressure fluid supplied to the ff!1 control valve 32 from the diverter valve 31 through the pipe E)2 is the power It is not supplied to the cylinder 34, but is refluxed from the first control valve 32 to the reservoir 3o via the piping 1)8, and the second control valve 33 is supplied from the diversion valve 31 to the piping 1).
The pressure fluid supplied via 2) is controlled in relation to the steering force, and the high pressure fluid is supplied to the 7 actuators 40b and 40d via piping 1), while the low pressure is +15 body to actuator 40a via piping P9
, 40C. Therefore - Oi): 1 wheel 1212
．． 1217 is capable of steering in the right direction and direction using only the steering force transmitted from the steering knob 19 via the steering gear mechanism.
Also, the rear wheel 13 R1131 is biased to the right by the actuators 40a, 40b, 40c, and 4tld. At this time, since the second control valve 33 supplies high-pressure fluid to each actuator 4()b, 40d, the fluid circulation 1i'lG IIE resistance on the second control valve 33 side increases; 33, the supply of a predetermined flow M of pressure fluid is ensured by the flow dividing valve 31. Therefore, the fluid pressure supplied to ζ, actuator 1lOb, 4(1(1) does not decrease, and the bias of rear wheels 131n, 13L 4(f
r is definitely done.

Next, when the steering force applied to the steering wheel I9 increases, the first control valve 32 also closes its variable orifices 32b, 3.
2d is narrowed down in response to the steering force, variable orifices 32a and 32c are opened, and high pressure fluid is supplied to the fluid chamber 3 of the power cylinder 34. Therefore,
The power cylinder 34 generates a steering assist force to press the rack 16 and reduce the steering effort of the steering handle 19. Further, the second control valve 33 has variable orifices 33a, 33b,
The flow path area of 33c and 33d changes more greatly than ζ.
Since the pressure fluid of 1 pressure is supplied to the actuators 40b and 40d, the deflection angle of the rear wheels 13R113L becomes larger. At this time, the flow rate of the pressure fluid supplied to each control valve 32, 33 is ensured by the flow dividing valve 3I at a predetermined amount corresponding to the flow dividing ratio. There is no mutual influence, and each control is performed according to the steering force.

As described above, in order to distribute the pressure fluid discharged by one pump 29 to the distribution valve 31 and supply it to each control valve 32, 33, the power steering device 39 and the compliance steer control device 4I operate independently, Better III
The rudder performance (;I is completely fine.

Furthermore, since the pump 29 discharges 7 and the pressure fluid is distributed by the flow dividing valve 31, there is no need to provide separate pumps for the power steering device 39 and the compliance steering control device 4, and this steering device can be made compact. Furthermore, the manufacturing costs are reduced.

2 and 3 show a second embodiment of the first invention. In this second embodiment, a flow valve 42 with a division ratio iiJ variant 5i distributes the pressurized fluid to the pump 29. At the same time, the diversion ratio of the diversion ratio iiJ modified diversion valve 42 is controlled in accordance with the vehicle speed. In addition, as mentioned above.

Same parts as the first embodiment 6. I will omit the explanation of what the same number is for the farm.

At No. 2121, 42 kl Bopon 2C (first controls the discharge pressure fluid: l/l 32, 1, and !).
jlill flll valve; Diversion ratio Fi to distribute to 33
This is a J-variant '7% ε valve, and this diversion valve 42 has a solenoid 42a connected to a control unit 1 unit 43, and the diversion ratio changes depending on the current value energized to the solenoid 42a. . The core 1-o-le unit 43 includes
A heavy speed sensor 44 is connected to detect the vehicle speed and output a signal indicating the vehicle speed. This control unit 43 controls the solenoid I" 42 a-\ according to the vehicle speed.
By changing the energizing current value, the flow dividing ratio of the flow dividing valve 42 is adjusted to the vehicle speed V.
Control accordingly.

As the variable flow ratio dividing valve 42, for example, one shown in FIG. 3 is used. In the same figure, 45 is a valve bousing in which a hole 45a is formed, and this housing 4
5 has a hole 45; an inlet 1-1 boat 46 connected to the pump 29;
At the same time, each control block 1, 32,; (2 connected to
Two outgoing ports 47.4)+ and ′ζ are formed. In the hole 45a of the bouncing 45, there is a phantom spool 49.
．． 50 is slidably inserted, and both openings of 1'L45a are closed by plugs 51.52G, and spool 4 is inserted between these spools 49.50 and plugs 51.52.
9. In the direction of approaching 50 (Ma J force spring 53
．． 54 has been reduced. These plugs 51.52 each have a hole 5 communicating with the 1 old-1 boat 47.48.
1a and 52a are formed, and a substantially cylindrical member 55 having a main hole 55a and two L control orifices 55b and 55C is sandwiched between opposing ends thereof.

Each spool 49.50 has a hollow shape with holes 49a, 50a opening on the side end surfaces of the plugs 5I, 52, and defines a fluid chamber 56.57 between the spools 49.50 and the plugs 51.52. Approximately ``L'' engages each other at each end.
Shape-shaped hook portions 49b and 50b are integrally formed. Further, each spool 49, 50 is formed with protrusions 49 (7, 50c) that can be in sliding contact with the inner surface of the member 55 in a substantially liquid-tight manner, and the grooves set by the protrusions 49C150C are controlled. l Refrigerators 55b, 55c open] 1 Chamber 5
)(, 59 are both achieved.

Further, each spool 49.50 has communication holes 49d, 50d, which communicate the chamber 58.59 and the fluid chamber 5[i, 57].
and the plugs 5I, 5 open to the fluid chambers 56 and 57.
rL4 that can communicate with the holes 51a and 52a of No. 2! lc,
! i0 (() is formed. These holes 49e, 50e
The holes 51a, 52a of the plug 51.52 form a variable orifice 60.61 whose flow area is changed by displacement of the spool 49.50. Incidentally, reference numeral 62 denotes a spring that is compressed between the opposing ends of the spools 49, 50 and biases each spool 49, 50 in a direction to separate them.

Further, one control orifice 55C of the member 55 includes:
A needle valve 63 driven by a solenoid 42a provided in the housing 45 is loosely inserted. This needle valve 63 is driven by the solenoid 142a to change the flow path area of the control orifice 55c. Note that the solenoid l' 42a is connected to the control unit 43 described above.

This variable flow ratio diversion valve 42 controls the fluid pressure flowing into one fluid chamber 57 from the inlet port 146 by the knee valve 63 changing the flow area of the control orifice 55 (1/8). The dividing ratio is controlled.That is, each diverting valve 42 has its respective spools 49 and 50 connected to the fluid chamber 5.
6.57 Fluid moon two forces and springs 53.54.
The spool 4 is displaced in response to the elastic force of the spool 4.
In response to the displacement of 9.50, the flow path surface fl of the variable orifice 60.61 changes, and the flow rate flowing out from each outlet boat 47.48 is divided into a predetermined distribution ratio, that is, the flow path surface fl of the variable orifice 60.61 is changed to
-S 14 (3 has a function C that maintains the divided flow ratio set at L).

Next, the effect will be explained.

In such a steering system, the pressure fluid Q discharged by the pump 29 is controlled in accordance with the vehicle speed, for example, as shown in FIG.
, l) or supplied to each control valve 32.3; 3 with flow characteristics as shown in FIGS. 7a and 7b. By the way, the first control ':l, :-no14:( of the power steering device 39 is the control block '32.\Supplied pressure fluid amount Q1.
is controlled to decrease at +iJ vehicle speed '1,
In addition, the pressure fluid amount Q2 supplied to the second control valve 33-supply'4 of the 21 appliance steering control device 4I is set at a high vehicle speed of 11,
Blasphemy - (increases) control. 1 poppy, pump 2
(The fluid IQ where + is 110- is Q-Q, -+-Q,
The relationship between IjL and 7. Therefore, the pressure of the power fluid supplied to the power cylinder 34 of the power steering device 39 decreases in the I1 vehicle speed range, and the steering assist force generated by the power cylinder 34 becomes small, allowing the driver to perform good steering. You can get a feeling. Conversely, the actuator 4fl a of the compliance steer control device 41,
Since the pressure of the pressure fluid supplied to 401+, 40c, and 40d increases in a convex vehicle speed range, the steering force applied to the steering wheel 19 increases in a high vehicle speed range.
The deflection angle of R113L is increased, and the turning performance of the vehicle is improved.

FIG. 4 shows a third embodiment of the first invention.

In this embodiment, the dividing ratio of the variable dividing ratio type diverting valve 42 can be changed by manual operation. Incidentally, the same parts G and the same parts as in the second embodiment are given the same numbers, and the explanation thereof will be omitted.

As shown in FIG. 4, an operation switch 64 is connected to the control unit 11) and the control unit 43 A1. This operation switch 64 is provided near the driver's seat and can be operated by the driver.
By operating this operation switch 64, the flow division ratio of the flow division valve 42 is changed.

In this steering device, when the driver operates the operation switch 44, the 1. Input!-rule'--yt-43 energizes the solenoid 142a of the diverter valve 42, and the diverter ratio is changed. Therefore, it is possible for the driver to set the turning characteristics and steering characteristics of the vehicle to the characteristics desired by the driver.

Furthermore, even if this steering device is installed in another type of vehicle, by operating the operation switch 64, the steering characteristics and turning characteristics can be set to the optimal values for the vehicle. Therefore, this steering device can be used in other types of vehicles without modification, increasing its usability.

Next, an embodiment of the second invention will be described based on the drawings.

FIG. 5 is a diagram showing an embodiment of the second invention. In addition, the same numbers are given to the same parts as the first embodiment and the second embodiment of the first invention (=t L−ζ
, the explanation is Ministry 1l18Jn.

First, to explain the configuration, 1) Piping P2 and piping PI
Pu is a second bypass pipe (bypass path) connecting pipe P3 and pipe I), and Pu is a second bypass pipe (bypass pipe) connecting pipe P3 and pipe I). P11 includes the well-known first and second
A pressure compensated flow control valve 65,66 is interposed. These first and second flow control valves 65 and 66 each have solenoids 1 to 65 connected to the control unit 43.
a, 66at4. The control unit 43 is connected to a vehicle speed sensor 44 and controls each of the flow control valves 65 and 66 in response to the vehicle speed.

Next, the effect will be explained.

Even in this steering system, the pressure fluid supplied to each control valve 32, 33 is controlled in accordance with the vehicle speed V, for example, as shown in FIG.
, b or flow rate characteristics as shown in Fig. 7 a and b. Therefore, the second embodiment of the first invention has been described. L lever 6, power steering device 39 and':
The steering control device 41 is configured to be responsive to vehicle speed, improving the turning performance of the vehicle and providing good steering.

In the steering device according to the second invention, the flow rate of the pressure fluid supplied to each power steering device 39 and the compliance steering control device 4 is independently controlled without being restricted by the discharge filter of the pump 29. can. In addition, the flow rate of the monthly pressure fluid supplied to each control valve 32, 33 is such that the pressure fluid distributed at a predetermined distribution ratio by the distribution valve 31 is further released by the flow rate control valves a11, Li5, (j[; - Since the control is carried out by recirculating the flow to C3o, the fluid Mc supplied from the diverter valve 31 is reduced by -1
The controllable range expands with each step.

(Effects of the Invention) As explained above, according to the first invention, the fluid used by the pump is distributed to the diverter valve (
In order to supply JJ, the front wheel vano steering device and the rear wheel! :V! The rudder devices no longer influence each other, and the rudder devices operate properly, improving their reliability.Furthermore, there is no need to install multiple pumps.
! Since it is an IA, it is possible to downsize the entire device and reduce manufacturing costs.

Further, in the second embodiment of the first invention, the diverter valve is configured to have a variable diverter ratio and the diverter ratio is controlled in accordance with the vehicle speed, so it is possible to obtain a good steering feeling. In addition, in the third embodiment, the diverting ratio of the diverting valve can be changed manually.
The driver can obtain desired steering characteristics or vehicle-specific steering characteristics and turning characteristics.

Furthermore, in the second invention, since the fluid discharged by the pump is distributed by the flow dividing valve and then further controlled by the flow rate control valve, each can be controlled separately, and the controllable range is expanded.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a first embodiment of a vehicle steering device according to the first invention, FIG. 2 is a schematic diagram showing a second embodiment of the vehicle steering device according to the first invention, and FIG. The figure is a sectional view showing the diverting ratio jiJ variant diverting valve shown in FIG. 2, and FIG. 4 is a schematic diagram showing a third embodiment of the vehicle steering device according to the first invention.
FIG. 5 is a schematic diagram showing an embodiment of the vehicle steering system according to the second invention, FIG. , b are flow rate characteristic diagrams each showing other aspects of control. 11 Heavy body, +2R1121, nii axis, 13 R, +3 L --1 & wheel, 19- Steering pan 1 l, 20----Steering gear mechanism, 29- Pump (pressure fluid light system), 3 ( )--Reservoir, 3-Diversion valve, 32.33- Control valve I'. 34 - cylinder, 39 - power steering device, 40 - actuator, 4 (-m- compliance steering 7 control device, 42 -
Diversion ratio rsJ modified momme flow rate, 43---Control 22 so 1-144---Vehicle speed sensor, 64---Operation switch, 65.66---Pressure compensation type flow control valve, P+o
, Pn-----Bypass pipe (]\Ipass l?8). Patent Applicant Nissan Motor Co., Ltd. Representative Patent Attorney Ugagun Part Figure 1 11 Figure 2 1 Figure 3 2 / Figure 4 1

Claims (5)

[Claims] (1) a steering gear mechanism that transmits the steering force applied to the steering wheel to the front wheels and biases the front wheels; a pressure fluid generating means that pressurizes fluid in a reservoir to generate pressure fluid; Two control valves control the pressure fluid generated by the power fluid generation means in response to the steering of the steering handle, and the pressure fluid controlled by one of the control valves is supplied (an auxiliary for deflecting the front wheels). A steering system for a vehicle includes a base cylinder that generates a force, and an actuator that biases a rear wheel by being supplied with pressure fluid controlled by the other force of the control valve, wherein the pressure fluid Generated by the means of generation)1.
−→IE force fluid is distributed and supplied to the two control valves at a predetermined flow ratio of 5J, and each time a branch valve is provided is 1 and V. (2) The vehicle steering system according to claim (1), wherein the flow dividing valve has a variable flow dividing ratio. (3) The flow dividing ratio of the flow dividing valve is controlled in accordance with the vehicle speed, and in a high vehicle speed range, the amount of pressure fluid supplied to the one control valve is greater than the amount of pressure fluid supplied to the control valve of the other force. Claim No. (2) characterized by reducing
Steering device for the vehicle described in Section 1. (4) The vehicle steering system according to claim (2), wherein the diverting valve has a diverting ratio that can be changed by manual operation. (5) a steering gear mechanism that transmits the steering force applied to the steering wheel to the front wheels and deflects the front wheels; a pressurized fluid generating means that pressurizes the fluid in the reservoir and generates pressurized fluid; ) - two control valves for controlling the pressure fluid generated by the force fluid generating means in response to the steering of the steering wheel, and one of the control valves controlling the pressure fluid by the horn of the control valve; A vehicle steering system comprising: a power cylinder supplied with pressure fluid to generate an auxiliary force to bias a front wheel; and an actucoator supplied with pressure fluid controlled by the other control valve to bias a rear wheel. a dividing valve which distributes and supplies the pressure fluid generated by the pressure fluid generating means to the two control valves-5 at a predetermined division ratio; a bypass path for returning at least one of the pressure fluid or the pressure fluid supplied from the flow divider valve to the external power control valve to the reservoir; A mid-circumference steering device characterized by having a flow rate control valve that controls the flow rate of pressure fluid to be recirculated.