JPS62105757A - 4-wheel-drive vehicle - Google Patents

Abstract

PURPOSE:To reduce interference of a rear wheel with a front wheel when carrying out an antilock control by avoiding increase in brake oil pressure while a braking operation is continued, when carrying out the antilock control of brakes on the rear wheel side. CONSTITUTION:An antilock control device 9 which controls the operation of modulators Mfl, Mfr, Mrl, Mrr in order to prevent wheels from becoming a locked condition, is provided on a brake oil pressure device 7. The antilock control device 9 has a front wheel control part 9a which separately controls the modulators Mfl, Mfr for front wheels Wfl, Wfr, and a rear wheel control part 9b which simultaneously controls the modulators Mrl, Mrr for rear wheels Wrl, Wrr. Signals from detectors 10l, 10r for detecting the wheel speeds of front wheels are inputted in the front wheel control part 9a, and signals from detectors 11l, 11r for detecting the wheel speeds of rear wheels are inputted in the rear wheel control part 9b.

Description

[Detailed Description of the Invention] A1 Objective of the Invention (1) Industrial Application Field The present invention provides a vehicle in which a power unit is connected to one of the front and rear axles, and the other axle has a high relative rotational speed. The present invention relates to a four-wheel drive vehicle that is connected to a power unit via a torque transmission mechanism that increases the amount of torque transmitted as the vehicle increases.

(2) Prior Art Conventionally, in four-wheel drive vehicles, each wheel is generally equipped with a brake.

(3) Problems to be Solved by the Invention Incidentally, in the above-mentioned vehicle, the front and rear axles are almost rigidly connected at all times, so if the braking oil pressure becomes excessive during a sudden brake operation, all the wheels simultaneously This will cause the situation to change.
Compared to front- or rear-wheel drive vehicles, stability during braking is improved, but stability against external disturbances and loss of antecedents remain. Therefore, it is desirable to provide the brake device with an anti-l:I'7 function.

However, anti-lock brakes basically control the brake torque for each wheel or each axle to maintain the slip rate of each wheel around an appropriate value, and the speed of each wheel or each axle is is required to be able to vary independently. On the other hand, in the 111 cars in which the front and rear axles are almost rigidly connected, the front and rear wheels interfere with the phase n. Appropriate control cannot be obtained with lock control.

On the other hand, when the front and rear axles are almost rigidly connected, if an appropriate slip rate is given to the wheels on one iIt axis, the slip and slip ratio of the wheels on the other axle will inevitably be approximately the appropriate value. This is the result.

Therefore, we installed brakes only on the front wheels to obtain braking force for all wheels, and also to reduce the anti-resistance of those brakes.
The problems mentioned in 11j can be solved by performing the 4-wheel drive control, and the present applicant has also proposed a four-wheel drive vehicle with such a configuration.

However, if only the front wheel brakes were used to brake all wheels, the load on the front wheel brakes would be increased, and in terms of space, it would be difficult to increase the capacity.

The present invention was made in view of the above circumstances, and in order to reduce the burden on the front wheels, brakes are also applied to the rear wheels.
)・The object of the present invention is to provide a four-wheel drive H1j in which anti-lock control of the rear wheel brake is performed to minimize interference from the rear wheel to the 111 brake.

+3. Structure of the Invention (Means for Solving the 11 Problems) According to the present invention, brakes are mounted on the small wheels of both axles, and the brake hydraulic system that controls the hydraulic pressure of each brake has a mechanism that prevents the wheels from entering a locked state. An anti-lock control device is provided which controls the brake system to release when the vehicle is about to move, and the anti-lock control device controls the play of the front wheels.
It has an 1111 transport control section that individually controls the rear wheels, and a rear control door section that controls the brakes of the rear wheels. In some cases, the brake hydraulic pressure is increased until the braking operation is completed, without avoiding it.

(2) Effect Once the anti-lock control is started, the rear wheel plate pressure will not increase until the braking operation is completed, and the rear wheel slip rate will be 1 (< 1). , interference from the rear wheels to the front wheels can be kept to a minimum.

(3) Example Hereinafter, an example of the present invention will be explained with reference to the drawings. First, in FIG. 1, a pair of left and right front wheels IA/fl, W
fr and a pair of left and right rear wheels Wrl and Wrr are respectively suspended at the front and rear parts of a vehicle body (not shown).

A pair of front axles Afff and Afr connected to the left and right front wheels W'β and Wrr, respectively, are connected to each other via a front differential Dr, and the left and right rear wheels Wrl are connected to each other via a front differential device Dr.

A pair of rear axles Arl and Arr respectively connected to Wrr are connected to each other via a rear differential device Dr. A power unit P including an engine and a transmission is connected to the human power section of the front differential device Dr.

Further, the rear propulsion shaft (1) r is connected to the input portion of the rear differential device Dr. This rear propulsion shaft P' is connected to the front 71 propulsion shaft Pi via a viscose clutch l as a torque transmission mechanism.
These are coaxially connected, and the driving force of the power pruniat P is transmitted to the front propulsion shaft 1) f.

Ru.

Hisni 1-scratch l c;+, phase g6 phase χ, 1 rotation possible, thousand 7 outer 2#3 and clutch inner 31
High viscosity M oil and a small amount of air that allows thermal expansion of the high viscosity oil are placed in the sealed oil chamber 4 defined by the cil, and splined to the clutch outer 2. ! The outer clutch plate 5 and a plurality of inner clutch members 6 spline-coupled to the clutch inner 3 are arranged in an overlapping manner. Moreover, each plate 5, 6 has an opening 1 that allows oil to flow.
] portion (not shown), the clutch outer 2 is integrated with the front propulsion shaft P, and the clutch inner 3 is integrated with the rear propulsion shaft Pr.

In this viscose clutch 1, when a relative rotation occurs between the clutch outer 2 and the inner 3, the lath platen 5 and 6 rotate 411M while shearing the high viscosity oil.
A viscous transmission of torque takes place between the two clutch plates 5.6. In addition, when the relative rotational speed increases further, a temperature gradient of 731M occurs between both latch + 5.6 due to the rise in oil temperature, and the strain caused by this and the rise in the pressure inside the sealed oil chamber 4 occur. Due to the synergistic effect, P is created between the two adjacent latch plates 5 and 6.
i! There may be areas where there is friction retention or where the gap is extremely small.
As a result, torque is frictionally transmitted between the clutch outer 2 and the clutch inner 3.

According to such a viscose clutch 1, 1; 1 part 1
Between the 1F base ib Pr and the rear 111 base axis Pr, that is, the 111i vehicle Arl, Δfr and the rear axle ΔrN,
Arr is always almost rigidly connected, and the front wheels Wrl, Wfr and the rear wheels Wr! ! , Wrr interfere with each other.

1] Brakes Bfp and Bfr are attached to the rear wheels WfJWfr, and the rear wheels Wr1. Wrr has a relatively small capacity brake Brl! , Brr are attached.

In FIG. 2, each brake Br1. Bfr,Brr,
Brake extraction system for controlling the hydraulic pressure of Brr; η7 is a tandem system having a pair of output capos 1-8a and 8b (two mask cylinders 8 and one output capo 1-8a for adjusting the hydraulic pressure supplied from the tandem cylinder 8 and one output capo 1-8a). Then apply the brake l3f1 for the left front wheel and the brake 4' B r r for the right rear wheel and the modulator Mff.
The hydraulic pressure supplied from f, Mrr and the other output capo 8b is adjusted to ilj:l, and the right front wheel brake 13 f r
and play for left rear wheel 4' 13 r i! ! Now, the modulators Mrr and Mrβ are calculated by bjN.

This play -1°・Hydraulic device 7 has wheels 1] 'y
The modulator Mf (
! , M1'r, Mrl, and Mrr.

An thousand lock system? :ftl device 9 plays songs (IQWre,
Wrr's seven ji-ta M (LM (r)
Ia・r front wheel system 1111 part 9, 3 and 7H'Q W
r n , W r r modulator Mr1. ．． Mr.
1; a detector IQN for detecting the wheel speeds of Wfff and Wfr;
+iii wheel control section 9. ．． A signal from a detector 11Lllr that detects the wheel speeds of the rear wheels Wre and Wrr is input to the rear wheel control section 9b.

Next, the configuration of the ζ, 1111 wheel control unit 9a will be explained with reference to FIG. 3, but the portion corresponding to one modulator Mre and the portion corresponding to the other modulator Mfr have basically the same configuration. Therefore, in the following, the parts related to the -force modulator Mre will be described with the subscript l, and the parts related to the other modulator Mfr will only be illustrated with the subscript r.

Wheel speed ■ detected by detector lOe to determine whether the wheel is about to enter a lock state. teeth,
It is input to the inverting terminal of the first comparator 13n, and the calculation time g l 21 ! This is input, and this function 1γ circuit 12
7! j: + wheel bending speed Q. is the second comparator 141
anti-1i, 'JAi child and third comparator 1511! Each non-inverting terminal is manually powered. In the first comparator 13N, its non-inversion;
A comparison is made between the one-wheel vehicle degree V and the wheel speed VW,
The first comparator 137 receives a signal λ that loosens the brake hydraulic pressure when V, l>V. is output from. Also, the second comparator 14
7! Then, a comparison is made between the manual input to the non-reversing terminal (V wheel deceleration Q0 and wheel acceleration 9),
Signal β to loosen the brake hydraulic pressure when 7wo>%/w
is output from the second comparator 14e. Further, the third comparator 15p compares Wii@wheel acceleration +*0 inputted to the inversion terminal with the wheel acceleration 9.1, and 99>1-Q. , the third comparator 1
51 outputs a signal α. The signal α is used to determine whether the wheel speed VW is being increased or not, and it is determined that when the auxiliary hydraulic pressure is loosened, 1υ1 is determined.

1st [Shibakuki 137! The output/terminal is AND game l
16g's input 01 is connected to the child and C)
Connected to the human power/terminal of 12 cable L l 7 e. Also the second comparator 147! The output terminal is AND game 1-1
fi (! and ()R'J' -) 17 Connected to the input terminal of e 'Mt. Furthermore, the output terminal of the third comparator 151 is connected to the human power terminal of the OR day 11fp.

The output terminal of AND game 1-166 is inverted and becomes AN
D-day 1-1811! , 19i'! (7) Connected to the input terminal and connected to the output terminal 20e. Also, the output terminal of 0[kugame 1-171 is A N +) S-1・18e's input terminal t, knee If) J'i, AM A N I) U''-1-18+1! output pass,
- The child is connected to the output pass and the i child 2212 (with the roller, reversed to AN I') game 1-1. It is connected to FF's human power/terminal. Furthermore, AND gate 1.9
The output of ff; f is connected to the output terminal 21e.

In the front wheel control section 91) configured in this way, the output terminal 2Qi! , Residual braking pressure is output from 20r.
A signal is output to increase the pressure of
``Another engine that keeps the braking pressure constant at 1N outputs tI.''

Ru. One modulator Mfρ has output terminals 20p, 2
In response to the message from 1e, 22 (!), the output terminals 20r, 21r,
It activated in response to No. 18 from 22r, and both brakes were activated! 3 (Q, B r r (7) −f
7 (-u tsukuij+ control is performed individually.

In the 41st Ri1, the rear width system? ]tl i'sl~91
) will be explained as +j, but after this, (1λ system f
:ll1 part 9F) (14 configuration is similar to the configuration of moe 1-control part 9 a, front wheel side j] 11 part 9a!, b °:) Then, Small letter 7! 2r = 4
JC: It is only shown in the drawings with the same reference numeral 11U marked.

In the rear wheel control section 9 b, please note [-1 should be the detector lI]
The wheel speed detected by A, llr is input to the Ll-select circuit 23, and the lower wheel speed selected by this t, J-select circuit 23 is the first comparison 2J1.
3 and is input to the encoder L7 unit 12.

Zunawara, left and right rear wheels Wrl! , Wrr, JRl
Anti-lock control is performed according to the wheel that is easier to lock, whichever wheel is easier to lock.
Both modulators Mr1. The operation of Mrr is controlled at the same time.

In addition, in this rear wheel control section 9b, a Flinopf 1 knob 24 is interposed between the output 0:;1 of the first comparator 13 and the input terminal of the OR gate 17. In other words, the output terminal of the eleventh cutter 13 is connected to the set input/terminal S of the Frynobuf [1 knob 24, and the output terminal 1'-(:1 is Ol? of the gate 17). It is connected to the input terminal I.Flip-flop 2 is also connected to a brake operation detector 26 which outputs a high level signal when it detects the braking 1/y operation by the brake pedal 25 (see Fig. 2).
No. 4 (input terminal!) is inverted and connected.

According to such a configuration, when a high level signal λ is output from the first comparator 13, the braking operation is detected with the end of the braking operation 11 until the output of 2G becomes LOW RAY and LE. The output of the flip-flop 24 remains at a high level until the input power of the flip-flop 24 reaches a high level, and therefore the output of the OR gate 17 also maintains a high level state. As a result, during anti-lock control, the output of the AND gate 19, that is, the output of the output terminal 21, does not become high until the braking operation is completed, and the play-1 oil pressure of the rear wheel brakes Brff and Brr is reduced or kept constant. Retained.

Next, to explain the operation of this embodiment, the control/assistance operation is performed while the heavy vehicle is running, and each brake 11 [e,
l3rr:Rr(!, Supplies brake hydraulic pressure to l1rr, and applies brake pressure to each wheel Wf e, Wf r ; Wr E,
Let us assume that the brake oil pressure becomes excessive when the braking force is increased to Wr r. At this time, the dredging control unit 9b controls the rear wheel Wr! , Wrr is likely to erode, outputs signals λ and β, outputs a pressure reduction signal from output terminal P20, and reduces the brake hydraulic pressure of the rear wheels Wrβ and Wrr. -The output is also at a high level, and the output of the OR gate 17 is at a high level.

When the possibility of one-touching is eliminated due to brake oil pressure reduction, the signals β and λ become low level, and the output ◇:
! The output of 1 child 20 becomes - level, but since the output of 01 engine gate I7 is high level, the output of C') I'2 game) 1B becomes high level, and the brake oil pressure is kept constant from output terminal 22. A signal is output to do this. Therefore, the rear wheel Wr7! , Wrr brake oil pressure is maintained at a low level up to iE, and the slip rate is reduced. Rear wheel Wr1, Wrr to iiiil =
w r l! , W f r is suppressed to a small level, and good anti-lock control is performed.

By the way, during braking, the striations '1' of the road surface may change and the viscosity coefficient may become smaller. In this case, the brake oil pressure may become too high if the brake oil pressure is kept constant. In this case, 1'? (J
I-r '7 Riga] 1-Shizou and '1' January analysis,
Two points Qgo, Lsu, Haile ＼ru (No. 8 λ, β is the 14th
- The second ratio 1 articulator 1:114 force 11 is applied, and play-1- hydraulic pressure reduction is performed F).

1j; The one-wheel control unit 9d is l! ! ! Since all Mfp and Mfr are individually controlled, the braking distance L? Excellent effects are obtained when the driving stability and running stability +i are 1-1. Zunawara, the front wheel W (1, Wfr and the rear wheel W r +!

In a four-wheel drive vehicle where Wrr is connected almost rigidly,
11;1 import Wr/! , Wrr control 1ffl 1 export Wr
(!, Wrr will be affected, so 1111 wheel speed 0, whichever is higher, J, %)
! Ha Ihireku who performs simultaneous control 11 of 9Mfr!・According to J(, +iiiI+iPW r(! ,
W r r O) One-sided force l:I y') 4c cow u
There is a mR characteristic, and the shadow of that is Wril on both rear wheels!
, Wrr, the rear wheels Wrl and Wrr slip, resulting in poor running stability. Also, the front wheels Wf12 with high load distribution. Wfr simultaneously controls both brakes L3fl and 13fr based on the front wheel speed on the low speed side.
-1- It is obvious that the braking distance will be improved if Select Bandai is adopted.

In the following seven embodiments, 4 is the width side thing 1 and the rotor Mrp1.
Mrr4-+: Simultaneous control is performed by +- select one direction, but even if individual control 10' is performed, 1.

In addition, the solinob flop 14 is connected to
You can set the throat output to 14゛ with a high error.
- Set the output to high/high level.

Effects of the C1 invention As described above, according to the present invention, the waste 1lc412 is
When the anti-lock control is applied to the brakes on the rear wheel side, the brake and -key hydraulic pressures are avoided from increasing while the braking operation is (, 'l'f, +L). Reduces the flow from the rear wheels to the front wheels during anti-rotation control.
Even though the front wheels and rear wheels are in almost rigid contact with the vehicle, good anti-lock control can be obtained, and 1j? It is possible to reduce the 1'L age of one wheel brake.

4 Detailed explanation of the drawings The first page shows a major embodiment of the present invention.
The diagram is 1113 diagrams of the drive, ribs, and shield, and number 21 is 11 of the brake system! ! FIG. 3 is a schematic diagram of the front wheel control section 11, and FIG. 4 is a schematic diagram of the rear 11 section.

I...1-Lukuden iF l? Hisco shoes as Jt +f□S.

-J・, 7...Play-1-Hydraulic system 6.9...An-J-+-t system 1111 Zo position, 941...Previous
Theory control department! +b...Rear wheel control section, Are, ノ\I'
r, Are e, Ar r− medium+Iid+, [(r
p, 13fr...Brake, 1)...Power 2! −
Ninoto, Wf e, Wf r, Wr 7! , Wr r・
-・Φwheel 1, ￥ Application entered Tree 111 technique ω [ft
S stock company 1'-7z.

Claims (1)

[Claims] A power unit is connected to either the front or rear axle, and the other axle is connected to the power unit via a torque transmission mechanism that increases the amount of torque transmitted as the relative rotational speed increases. In four-wheel drive vehicles,
Brakes are attached to the wheels of both axles, and the brake hydraulic system that controls the hydraulic pressure of each brake is equipped with an anti-lock control device that controls the brake hydraulic pressure to loosen when the wheels are about to enter a locked state. The anti-lock control device has a front wheel control section that individually controls the front wheel brakes and a rear wheel control section that controls the rear wheel brakes, and the rear wheel control section detects when the rear wheels are likely to lock during braking. A four-wheel drive vehicle characterized in that the four-wheel drive vehicle is configured to avoid increasing brake rake hydraulic pressure by continuing it until the end of a braking operation when a judgment is made.