JPS62105750A - 4-wheel-drive vehicle - Google Patents

Abstract

PURPOSE:To carry out an antilock control efficiently and effectively by reducing brake oil pressure of rear wheels only when said rear wheel is in a tendency to be locked while reduction in brake oil pressure of front wheels is maintained for a certain period of time or more. CONSTITUTION:An antilock control device 9 for controlling the operation of modulators Mfl, Mfr, Mrl, Mrr, to prevent a wheel 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 for separately controlling the modulators of the front wheels and a rear wheel control part 9b for simultaneously controlling the modulators of rear wheels. The front wheel control part 9a and the rear wheel control part 9b are constructed in such a way that reduction in front-wheel brake oil pressure is maintained for a certain period of time or more, while rear-wheel brake oil pressure is reduced only when the rear wheels are about to be locked.

Description

[Detailed Description of the Invention] A1 Object of the Invention (1) Industrial Field of Application The present invention is directed to one of the front and rear axles, in which a pa/no unit is connected to the axle, and either the front or rear axle is , the bow is connected to the power unit 11 via a torque transmission mechanism in which the amount of torque transmitted increases as the speed increases, and play = lt is applied to the wheels of each axle.

Regarding the four-wheel drive vehicle equipped with each.

(2) Conventional technology Conventionally, four-wheel drive vehicles have been developed to improve the vehicle's maneuverability and driving performance on road surfaces with a low coefficient of friction. Attempts to install a locking brake device have also been unsuccessful.

(3) Problems to be Solved by the Invention However, it would be inconvenient if the anti-lock brake device used in conventional two-wheel drive vehicles was used as is in the above-mentioned four-wheel drive vehicles.
Sign. However, in a four-wheel drive vehicle, the front wheels and rear wheels interfere with each other in phase q, making it impossible to obtain a sufficient unlock/y-lock effect.

The present invention has been made in view of such circumstances, and includes:
1? An object of the present invention is to provide a four-wheel drive vehicle that efficiently and effectively performs anti-lock control of the front wheels and rear wheels.

B6 Structure of the Invention (1) First Stage for Solving the Problems According to the present invention, brakes are mounted on the wheels of both axles, and the brake hydraulic system for controlling the hydraulic pressure of each brake is equipped with a brake for each wheel. An anti-lock control device is attached to reduce the brake hydraulic pressure when the vehicle is about to enter a locked state, and the anti-lock control device includes a 1111 wheel control section that individually controls the front wheel brakes, and a rear wheel brake control section. The front wheel control section and the rear wheel control section control the plate hydraulic pressure of the rear wheels only when the reduced pressure of the brake hydraulic pressure of the front wheels continues for a certain period of time or more and the rear wheels are about to lock. It is configured to reduce the pressure.

(2) Effect The brake hydraulic pressure of the rear wheel brake is reduced only when the front wheel is in a state where it is likely to lock up for a certain period of time, and the rear wheel is also in a state where it is likely to lock up. Sometimes, the 1111 wheel interferes with the rear wheels, so anti-lock control of the front wheels alone can prevent the rear wheels from entering an ill-locked state.

(3) Embodiment Hereinafter, an embodiment of the present invention will be explained with reference to the drawings. First, in FIG. 1, a pair of left and right front wheels Wff! , Wf
r and a pair of left and right rear wheels Wri! , Wrr are suspended on the 11; 1 part and rear part of the body (not shown), respectively.

A pair of front axles AfN and Afr connected to the left and right n;

A pair of rear axles Ar7 each connected to Wrr! ,A'r
is connected to +11:[- via the rear differential Dr. The input section of the front differential D" is connected to the power unit (I) including the SC amplifier and the transmission.

In addition, the input section of the rear differential VJ device 1) r has the rear 11t,
φ1h1)r'h<connected. This rear propulsion shaft 1)
r is )・Viscose clutch l as a torque transmission mechanism
It is coaxially connected to the front HI advance shaft pr through the front HI advance shaft pr, and the driving force of the power unit I-P is transmitted to the front HI advance shaft 1''f.

The viscose clutch 1 has a small amount of air in a sealed oil chamber 4 defined between the latch outer 2 and the clutch inner 3, which are rotatable relative to each other, to allow thermal expansion of the highly viscous oil and its highly drying oil. Once enclosed, a plurality of outer clutch plates 5 spline-coupled to the clutch outer 2 and a plurality of inner clutch plates 6 spline-coupled to the Taranochi inner 3 are arranged in an overlapping manner. Moreover, each plate 5, 6 is provided with an opening (not shown) that allows oil to flow, and the clutch outer 2 is integrated with the front propulsion shaft 1''f, and the Taranochi inner 3 is integrated with the rear propulsion shaft Pr. Ru.

In this viscose clutch 1, when relative rotation occurs between the clutch outer 2 and clutch inner 3, both clutch plates 5.6 rotate relative to each other while shearing high viscosity oil, and torque is generated between both clutch plates 5.6. Viscous transmission takes place. Furthermore, when the relative rotational speed increases further, a complicated temperature gradient occurs in both clutch plates 5.6 due to the increase in oil temperature, and due to the synergistic effect of the strain caused by this and the pressure increase in the sealed oil chamber 4, the adjacent There is a signal with an extremely small frictional engagement part or gap between the two clutch plates 5 and 6, and as a result, 1 lk of I power is transmitted at the edge outer 2, clutch, and edge 1' inner 3 II. It is done.

According to such a viscose clutch 1 -1);1
Between the front propulsion shaft Pf and the rear propulsion shaft Pr, that is, the front axis /l#, Afr and the rear axle Δr6. Arr is always in the almost rigidly connected state 11th, and the front wheel Wf7!
, Wfr and the rear wheels WrllWrr interfere with each other.

Brake 817 on front wheels Wfff and Wfr! , B[r are installed, and relatively small-sized brakes [3rff, l3rr are installed on the rear wheels Wrρ, Wrr.

In Fig. 2, each brake Bfff, Bfr, 8ri
! The brake hydraulic system 7 that controls the hydraulic pressure of the left front wheel adjusts the hydraulic pressure supplied from a tandem master cylinder 8 having a pair of output ports 1-8a and 8b and one output boat 8a. A modulator Mr1. which leads to the brake Bfl and the right rear wheel brake Brr. Mrr and the hydraulic pressure supplied from the other output boat 8b? Adjust the brake A for the front right wheel and the brake for the left rear wheel Br (l).
It is equipped with modulators Mrr and Mrl that lead to. This brake hydraulic system 7 includes a modulator Mf11. to prevent the wheels from entering a locked state. Mr r, M
r 7! , Mr. An anti-lcock control device 9 is attached to control the operation of Mr.

The anti-lock control device 9 includes a front wheel control section 9a that individually controls front/wren and wrr modulators Mfff and Mfr, and a rear wheel Wr12. Wrr modulator Mrf
f and Mrr simultaneously, and a detector LO1, which detects the wheel speed of the front wheel W(1, Wfr).
The signal from for is input to the front wheel control '411 part 9a,
Detector 11c that detects the wheel speed of rear wheels Wry and Wrr
A signal from lIr is input to the rear wheel control section 9b.

Next, referring to FIG. 3 (jtυ-), the front wheel control section 9.
I will explain the configuration of l, but on the other hand, ; Norake Mf
i! Since the parts corresponding to the one modulator Mf+ and the other modulator Mf+ have basically the same configuration, in the following, the parts related to one modulator Mr (!) will be omitted and the subscript e will be added and explain the other dry; Yureta M
Parts related to rr are only shown with the subscript r.

Determine whether the wheels are about to enter the lock state.
The wheel speed V detected by the detector 101 in order to determine jJi. is input to the inverting terminal of the first comparator 131 and is also input to the arithmetic circuit 121.
Ilf rotation degree Ω8 obtained at p, second comparator + 4p inversion end Lb and third comparator 15e (7) non-inversion;
1r, 11, zo('), input. 1st comparison 2HI
In 3/, its non-inversion ◇::'+7 A signal λ for relaxing the oil pressure is output from the first comparator 131.
In the comparator 14ff, the reference wheel deceleration -Q is input to the non-inverting terminal. 0 is compared with the wheel acceleration*, and when -9,0>91, a signal β for relaxing the braking oil pressure is output from the second comparator 14p. Furthermore, the third
Comparator 157! Then, the reference wheel acceleration ←98° manually applied to the reversing terminal is compared with the wheel acceleration 9, and 9>+Q. , the third comparator 151
A signal α is output from. This signal α is the wheel speed VW
This is to determine whether or not the speed is increasing.
Based on this signal α, it is determined when to continue loosening the brake hydraulic pressure.

The output terminal of the first comparator 13I2 is A N +) gate 1
6i, and is connected to the input terminal of OR gate 17.
Connected to the input/terminal of e. Further, the output terminal of the second comparator 141 is connected to the A N D gate 16p and the OR data 1-
1.7 N input 0:1; connected to child. Furthermore, the third
The output terminal of the comparator 1512 is OR/J---1-17r
connected to the input terminal of

AND game 1-161! The output terminal of is inverted and AND
It is connected to the input terminal of the gate 18L and 19f, and is also connected to the output terminal 2()e. Also, OR gate 1
The output terminal of the AND gate 181 is connected to the input terminal of the AND gate 181, and the output terminal of the AND gate 181 is
Connected to the output terminal 221 and inverted to AN
D Gate 197! connected to the input terminal of Further AN
D game) 197! The output terminal of is connected to the output terminal 21N.

In the front wheel control unit 9b configured in this way, a signal for reducing the braking pressure is output from the output terminal 20C20r, a signal for increasing the braking pressure is output from the output terminals 21x and 2ir, and a signal for increasing the braking pressure is output from the output terminals 22e and 22r. A signal should be output to keep the pressure constant. One modulator M[e is
It operates according to the signals from the output terminals 2゜l, 21L22N, and the other modulator Mfr output terminals 20r, 21r.
, 22r, and thereby both plays = t-13ri! , Brr are individually controlled.

However, the output terminal of the 8ND START 161.16r is the timer circuit 247! , 24r. This timer circuit 247! , 24r is the fourth [′″!A
[When No. 3 (No. 81) is input, a high-level signal is output after a certain period of time 'I'' from the rising edge of No. (M), and responds to the falling edge of the input signal. and output (No. 8 goes down by ♂ 1.: Both evenings and now concave A 2
The outputs 'J::'+''P of 4ff and 24r are connected to the input j:7 of the OR gate 25, respectively.

By the action of both timer circuits 24C24r, the front wheel control section 9
At a, when the signal to reduce the brake hydraulic pressure of both brakes Brff and 13fr continues for a certain period of time 'r, 0[? The output of gate 25 becomes high level, and this OR
Is the output of the 25 on Day 1 rear wheel driven due to the line 26? :tl
It is transmitted to the first part 9b.

In FIG. 5, the configuration of the rear wheel control unit 9b will be explained.
The structure is similar to that shown in Fig. d, and the parts corresponding to the front wheel control section 9a are only illustrated by using the same reference numerals as 1 and 1 without adding suffixes n and r.

In particular, the rear wheel control unit 911 should control the detector 111.
, Ilr is input to the 1-select circuit 23, and the low force wheel speed selected by this 11-select circuit 23 is input to the 11-select circuit 23.
3 and the computing unit 12.

Of the left and right rear wheels Wrp and Wrr, anti-hook control should be performed to match the middle wheel with the lower small wheel speed.
Both modulators Mr1. The operation of Mrr is controlled at the same time.

Furthermore, in this rear wheel control section 9b, the output terminal of the first comparator 13 is connected to one input terminal of an AND gate 27, and the line 26 is connected to the other input terminal of the AND gate 27. Further, the output terminal of the ΔND gate 27 is connected to the output terminal 20, and inverted to the input terminal of the NO gate 1-18.19.

Therefore, in the rear wheel control section 9b, the front wheel control section 9a brakes BI'7! , Bfr for at least one of the rear wheels Wrf! for a certain period of time T or more (only when the pressure is reduced at -).

Wrr's Play-1-Song IE Decompression becomes possible.

Next is Konomi IIi! ! To explain the operation of an example, in a vehicle where the front axles Are, Afr and the rear axles rp, Arr are almost rigidly connected, the front wheels Wre, Wf
When there is a tendency to lock in R, the rear wheel Wr1. Wr.
1) There is always a cocking tendency in r, and in this case, the front wheel control unit 9a loosens the brake hydraulic pressure of the front wheels wre,w[', thereby controlling the front wheels WE1.Wrr and the rear wheels Wr7!
, Wrr are both alleviated from locking tendency. Moreover, the brakes BfCBfr of the front wheels wrp and wr are controlled by the front wheel control unit 9.
Since the individual control is carried out at step a, even if only one of the front wheels Wfl and Wfr is in the lock 1 direction, the anti-rotation control will be carried out without any problem.

iii! When the ``1'' tendency of the rear wheels Wrp and Wrr is not resolved even by a decrease in the brake oil pressure of i2wrβ and Wfr, that is, the signal for reducing the pressure of the play 1 oil pressure in the front control units 9 and 3 is activated for a certain period of time T. Even if the lock of the rear wheel Wr12.Wrr persists in the following -1-1, if the lock of the rear wheel Wr12.
The brake hydraulic pressure of rJ nrr is reduced, and the rear wheel Wrf
The locking tendency of f and Wrr is eliminated.

Also, when only the rear wheels Wrff and Wrr turn by 1'', the rear wheels Wr7! , Wrr is the front wheel Wfρ.

Rear wheel Wr7 because it receives the shadow of Wrr! , Wrr's locking tendency is not strong and can be ignored.

C1 According to the present invention, when the brake oil pressure of one wheel is maintained for a certain period of time or more, the rear wheel tends to lower. The power of the case, the play of the latter part-1
-Since the oil pressure is reduced, the front and rear wheels can be controlled efficiently and effectively by using the mutual control between the front and rear wheels. .

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic diagram of the drive system, FIG. 2 is a schematic diagram of the four systems of the play-1 system,
Fig. 3 shows a schematic IA of the front wheel control section, and Fig. 4 shows the timer circuit 4. Figures 'i1'1 and 5 are schematic diagrams of the rear wheel control section.

Claims (1)

[Claims] A power unit is connected to one of the front and rear axles, and the other of the front and rear axles 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 a four-wheel drive vehicle where a brake is attached to each wheel on each axle, the brake hydraulic system that controls the hydraulic pressure of each brake has an anti-static system that controls the brake hydraulic pressure to reduce the pressure when the wheels are about to enter a lock state. A lock control device is attached, and the anti-lock control device includes a front wheel control section that individually controls the brakes of the front wheels, and a rear wheel control section that controls the brakes of the rear wheels. The four-wheel drive vehicle is characterized in that the part is configured to reduce the pressure of the brake oil pressure of the rear wheels only when the pressure reduction of the brake oil pressure of the front wheels continues for a certain period of time or more and the rear wheels are likely to lock.