JP2587618B2 - Anti-skid control method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-skid method for a vehicle whose drive system can be switched from two-wheel drive to four-wheel drive, and particularly to a smooth and effective anti-skid method for four-wheel drive. This is to ensure skid control.

[Background of the Invention] As an anti-skid control system for a two-wheel drive, for example, a front-wheel drive (FF) type vehicle, a system that controls each system based on a select row for each system wheel in a cross-pipe type two system, There are three systems in which the front wheels are controlled independently and the rear wheels are controlled based on the select row. There are anti-skid control systems for vehicles that can switch between two-wheel drive and four-wheel drive. Is applied, when the drive system is switched from two-wheel drive to four-wheel drive, all the wheels are in a direct connection state at the time of four-wheel drive. In the above three systems, there is a speed difference between the axles of the front and rear wheels,
Anti-skid control does not operate normally due to such axle speed difference, so that anti-skid control does not operate normally, or so-called "jerky feeling" occurs, or the vehicle swings, resulting in poor directional stability. You will run into problems.

[Object of the invention]

According to the present invention, when the drive system is switched from two-wheel drive to four-wheel drive, anti-skid control is switched so that all wheels are simultaneously controlled in accordance with the switch. An object of the present invention is to provide an anti-skid control method capable of effectively avoiding points.

[Configuration of the invention]

According to the anti-skid control method of the present invention, when two wheels are driven, for example, a three-channel (three-system) system in which front wheels are independently controlled based on a select row or a so-called cross-pipe two-system system. When the drive system is switched from two-wheel drive to four-wheel drive, the timing of pressurizing and reducing the brake pressure of all wheels is simultaneously controlled with the switching.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows a configuration of an example of an anti-skid control device to which the present invention can be applied.
1 is a brake pedal, 2 is a master cylinder, 3 is a wheel,
4 is a wheel cylinder of a wheel brake device, 5 is a gate valve, 6 is a solenoid valve device for both pressurization and holding (hereinafter referred to as a pressurization valve), 7 is a solenoid valve device for decompression (hereinafter referred to as a decompression valve), 8 is the master cylinder 2 and the gate valve 5
The gate valve 5, which is a main path for transmitting brake hydraulic pressure connected to the wheel cylinder 4 of the wheel brake device via a pressure valve, has cylinders 10 and 11 with a built-in differential pressure moving piston 9. The valve 12 of the gate is closed when it moves to the left in the drawing by pressure, and when the valve 12 of the gate is closed, the master cylinder side and the wheel cylinder side are shut off in pressure. 13 is a check valve and 14 is a relief valve.

Reference numeral 15 denotes a wheel speed detector (speed sensor) provided in association with the wheel 3, and inputs detection information to a control circuit 16. The control circuit 16 is generally configured using a microcomputer. In this embodiment, the control circuit 16 is configured to have a control function corresponding to the block diagram shown in FIG. cage, based on the detection information from the speed sensor 15, the hydraulic retention signals S ₁ or vacuum signal S ₂
Is output.

The pressure valve 6 is a normally open type, is switched to the closed state by the hydraulic holding signals S ₁ from the control circuit 16, (which the hydraulic retention state) to cut off the main path 8. On the other hand, the pressure reducing valve 7 is a normally closed type, and a pressure reducing signal from the control circuit 16 is output.
The circuit is switched to the open state by S ₂ and the wheel cylinder 4
The internal pressure oil is pumped to a pressure accumulator 19 via a reservoir 17 and a pump 18, and is connected to a bypass path 20 between the gate valve 5 and the pressure valve 6 so as to return the pumped pressure oil.

In the above, the system related to one wheel has been described for the sake of simplicity of illustration and description. In practice, however, a similar system is provided for each wheel, and according to the present invention, , Each of which is associated with one another in a unique manner as described below.

2 to 6 are block diagrams each showing an embodiment of a configuration capable of implementing the method of the present invention. FIG. 7 is a diagram showing a piping system of a brake device to which the configuration of FIGS. 2 to 5 can be applied. It is a figure for explaining. 2 to 7,
Parts corresponding to FIG. 1 are denoted by similar reference numerals,
In these figures, FR is the front right wheel, FL is the front left wheel, and RR
Indicates the right rear wheel, and RL indicates the left rear wheel, and indicates that the characters are related to the respective wheels when used as subscripts.

In FIG. 2, 15 _FR , 15 _FL , 15 _RR, and 15 _RL are speed sensors, respectively, and 21a and 21b are pressure reducing valves (right and left rear wheels, left front wheels, and right rear wheels provided in a brake device). Or a pressure valve). Although FIG. 1 shows both the pressurizing valve and the depressurizing valve, only one of them is shown in FIGS. 2 and subsequent drawings for convenience of explanation and illustration.

In the embodiment shown in FIG.
a, 22b, 22c, logic circuit 23a, 23b, 23c, and OR gate
There is provided a control circuit 30 including 24a, 24b and amplification circuits 25a, 25b, and the speed sensors _15FR , _15RL are controlled by the low select circuit 22a of the control circuit 30,
Then, the speed sensors 15 _FL and 15 _{FL are} supplied to the row select circuit 22 b.
_RR is connected. On the output side of these row select circuits 22a and 22b, changeover switches 26a and 26b are provided for the purpose described later. Normal two-wheel drive (F
F) At the time, these changeover switches 26a and 26b are in the positions shown in the figure, and accordingly, the low select circuits 22a and 22b are connected to the logic circuit 23 via the changeover switches 26a and 26b, respectively.
a, 23b. That is, at the time of two-wheel drive,
The anti-skid control is performed on the basis of a select row for each system wheel in two crossed piping systems of the right front wheel and the left rear wheel, and the left front wheel and the right rear wheel.

In such a state, the driving method is two-wheel drive (FF)
When the vehicle is switched to the four-wheel drive, the signal indicated by the block 40 generated in accordance with the switching indicates that
The changeover switches 26a and 26b are respectively switched from the illustrated positions, and the row select circuits 22a and 22b are connected to the other row select circuit 23c via the changeover switches 26a and 26b. That is, at the time of four-wheel drive, all the wheels are simultaneously controlled in the timing of increasing / decreasing the brake pressure of all the wheels based on those select rows.

In the embodiment of FIG. 3, the row select circuits 32a, 32b, 32
c, logic circuits 33a, 33b, 33c, and OR gates 34a, 34b
And a control circuit 50 including amplification circuits 35a and 35b.
Is provided, the low-select circuit 32a is connected to the speed sensor 15 _FR, 15 _RL, low-select circuit 32b speed sensor 15 _FL, 15 _RR is connected to and low-select circuit to 32c speed sensor 15, _RR and 15 _RL are connected. In this embodiment, the row select circuits 32a, 32a
Three changeover switches 36a, 36b, 36c are provided on the output side of b, 32c, respectively. In the state shown in the drawing, that is, in two-wheel drive (FF), the low select circuits 32a, 32b respectively change the changeover switches 36a, 36b. It is connected to the logic circuits 33a and 33b via the power supply. That is, at the time of two-wheel drive, as in the case of the embodiment shown in FIG. 2, the select row for each system wheel is used as a reference in the cross-pipe type two systems of the right front wheel and the left rear wheel, and the left front wheel and the right rear wheel. Thus, anti-skid control is performed.

In such a state, the driving method is two-wheel drive (FF)
Is switched to four-wheel drive, the switches 36a, 36b, and 36c are switched from the positions shown in the drawing by the signal shown by the block 40 generated along with this switching, as in the case of FIG. And the row select circuit 32
a and 32b are separated from the logic circuits 33a and 33b, and the low select circuit 32c to which the speed sensors 15 _RR and 15 _RL are connected.
Are connected to the logic circuit 33c. That is, in this embodiment, at the time of four-wheel drive, all wheels are simultaneously controlled based on the select low of the rear wheels.

In the embodiment of FIG. 4, the low select circuits 41a, 41b, the high select circuit 42, the logic circuits 43a, 43b, 43c, and the OR
A control circuit 70 including gates 44a and 44b and amplification circuits 45a and 45b is provided. The speed sensors 15 _FR and 15 _RL are connected to the low select circuit 41a of the control circuit 70, and the speed sensor 1 is connected to the low select circuit 41b.
5 _FL and 15 _RR are connected, and all speed sensors 15 _FR to 15 _RL are connected to the high select circuit 42. Furthermore, the low select circuits 41a and 41b and the high select circuit
The output side of 42 is provided with changeover switches 46a, 46b, and 46c. In the state shown in FIG.
It is connected to the logic circuits 43a and 43b via 46a and 46b, and the high select circuit 42 is separated from the logic circuit 43c. That is, also in this embodiment, at the time of two-wheel drive (FF), as in the embodiment shown in FIGS. 2 and 3, the right front wheel and the left rear wheel and the left front wheel and the right rear wheel are formed. The anti-skid control is performed on the basis of the select row for each system wheel in the two cross piping type systems.

In such a state, the driving method is changed from two-wheel drive (FF) to four.
When the mode is switched to the wheel drive, the above-described FIGS.
As in the case of the embodiment shown in the drawing, the changeover switches 46a, 46b and 46c are switched from the positions shown in FIG. 41b is the logic circuit 43a, 4
Disconnected from 3b, all of the speed sensor 15 _FR ~15 _RL
Is connected to the logic circuit 43c via the changeover switch 46c. That is, the fourth
In the illustrated embodiment, during four-wheel drive, all wheels are simultaneously controlled based on their select highs.

In the embodiment of FIG. 5, the row select circuits 61a, 61b, 61
c, high select circuit 62, and logic circuits 63a, 63b, 6
A control circuit 90 including 3c, OR gates 64a and 64b, and amplifier circuits 65a and 65b is provided. Speed sensors 15 _FR and 15 _RL are connected to the low select circuit 61a,
The low select circuit 61b is connected to the speed sensors 15 _FL and 15 _RR , and the high select circuit 62 is connected to all of the four speed sensors 15 _FR and 15 _RL . Still another row select circuit 61c includes the row select circuit 61a.
And the outputs of 61b are connected. Further, switches 66a and 66b are provided on the output side of the low select circuits 61a and 61b, and two switch 67 and 66c connected in series are provided on the output side of the high select circuit 62. In this embodiment, the changeover switch 66
The switches a, 66b and 66c are switched in accordance with the switching of the driving system as in the case of FIG. 3 or FIG.
Reference numeral 7 denotes a switch which can be switched by a signal indicated by a block 60 obtained by detecting whether the road surface is high μ or low μ. Is the case. Regarding the three changeover switches 66a, 66b and 66c, the state shown in the figure is for two-wheel drive (FF), as in the case of the above-described embodiment.
At the time of wheel drive (FF), the low select circuits 61a and 61b are connected to the logic circuits 63a and 63b via the changeover switches 66a and 66b, while the high select circuit 62 is set to a changeover switch.
It is separated from the logic circuit 63c by 66c. Therefore, in the case of the embodiment of FIG. 5 as well, in the two-wheel drive (FF), as in the case of each embodiment shown in FIGS. Anti-skid control is performed on the basis of a select row for each system wheel in the two crossed piping systems of the right rear wheel.

In such a state, the driving method is changed from two-wheel drive (FF) to four.
When the mode is switched to the wheel drive, the block 40 generated in accordance with the switching is switched, as in the above-described embodiments.
According to the signal indicated by, the changeover switches 66a, 66b,
66c is switched from the position shown in the figure, and the low select circuits 61a, 61b are separated from the logic circuits 63a, 63b, respectively. It is connected to a logic circuit 63c via 67 and a changeover switch 66c. That is, in the embodiment of FIG. 5, when the road surface is high μ during four-wheel drive, all wheels are simultaneously controlled based on their select highs. In such a state, when it is detected that the road surface has become low μ, the changeover switch 67 is operated by the signal indicated by the block 60 obtained by the detection of the road surface state as described above.
The switch is switched from the position shown in the figure, and the high select circuit 62 is disconnected from the logic circuit 63c. This time, the low select circuit 61c connected to the low select circuits 61a and 61b switches the changeover switch 67 and the changeover switch 63c as described above. It is connected to the logic circuit 63c through the interface. That is, when the vehicle is driven by four wheels and the road surface is low μ, all the wheels are simultaneously controlled based on their select lows.

Although the embodiment of the configuration capable of implementing the method of the present invention shown in FIGS. 2 to 5 has been described above, referring to FIG. 7, the piping of the brake device to which any of these configurations can be applied. The strain is shown. 7, reference numerals 100a and 100b denote modulators including the gate valve, the pressurizing valve, the depressurizing valve, and the like described above with reference to FIG. 1, respectively. The modulator 100a is a wheel cylinder F of a brake device for the right front wheel FR and the left rear wheel RL. Piping to _FR and 4 _RL 10
It is connected via 1a, while the modulator 100b is connected through a pressure oil pipe 101b to the wheel cylinders 4 _FL and 4 _RR brake devices for the left front wheel FL and the right rear wheel RR. That is, the brake device of FIG. 7 is of a cross-pipe type, and as described above with reference to FIGS. 2 to 5, during two-wheel drive, each of the brake devices is provided via each of the modulators 100a and 100b. When anti-skid control of a cross-pipe type two system based on a select row for each system wheel is applied, and the system is switched to four-wheel drive in this state, the control circuit 102 is controlled by a signal 40 generated in accordance with the switching. As described above, all wheels FR, FL, RR, and RL are simultaneously controlled during four-wheel drive, as described above. Note that this control circuit 102 corresponds to FIGS.
In FIGS. 5 and 5, 30, 50, 70 and 90, respectively.
It will be apparent that this corresponds to the control circuit indicated by.

Finally, referring to FIG. 6, yet another embodiment of the present invention is shown. In this embodiment, the row select circuit
The control circuit 110 includes 81a, 81b, logic circuits 82a, 82b, 82c, 82d, OR gates 83a, 83b, 83c, and amplifier circuits 84a, 84b, 84c. In this embodiment, the speed sensors 15 _RR and 15 _RL are low select circuits.
Connected to 81a, other speed sensors 15 _FR, 15 _FL, respectively through change-over switch 85a, a 85b logic circuit 82a, 8
Connected to 2b. Further, the row select circuit 81
a is connected to the logic circuit 82c via the changeover switch 85c. The speed sensors 15 _FR and 15 _FL and the low select circuit 81a are provided with changeover switches 85a and 85b, respectively.
And 85c, and can be connected to a row select circuit 81b, and this row select circuit 81b is connected to a logic circuit 82d.

In FIG. 6 as well, the state shown is for two-wheel drive (FF), but in this embodiment, during two-wheel drive, the right front wheel and the left front wheel are mutually connected by pressure reducing valves (or pressurizing valves) 21a and 21b. The so-called three-channel type anti-skid control is performed in which the right rear wheel and the left rear wheel are controlled by pressure reducing valves (or pressure valves) 21c and 21d based on their select lows. That is, in this respect, it can be seen that the embodiment of FIG. 6 is different from the embodiments (intersecting piping type two systems) shown in FIGS. 2 to 5.

In such a state, the driving method is changed from two-wheel drive (FF) to four.
When the mode is switched to the wheel drive, as in the embodiments of FIGS. 2 to 5, the changeover switch 85 is generated by the signal indicated by the block 40 generated along with the switching.
a, 85b, 85c is switched from the illustrated position, the speed sensor 15 _FR, 15 _FL, and low-select circuit 81a (in this is connected with the speed sensor 15 _RR, 15 _RL as described above) they are Selector switches 85a, 85b, 85
It is connected to the row select circuit 81b via c. That is, in the embodiment shown in FIG. 6, when four wheels are driven, all the wheels are simultaneously controlled based on their select low.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, when the drive system is switched from two-wheel drive (FF) to four-wheel drive, anti-skid control is performed so that all wheels are simultaneously controlled. Is switched, anti-skid control during four-wheel drive is performed smoothly and effectively, and phenomena such as "jerky feeling" and swing of the vehicle as described at the beginning can be avoided. At the same time, there is no interference between the transmission and the differential, so that the durability of those mechanisms is improved, and the occurrence of vibration and abnormal noise of the vehicle is reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an anti-skid device to which the present invention can be applied, FIGS. 2 to 6 are block diagrams showing an embodiment of a configuration capable of implementing the method of the present invention, and FIG.
The figure is an explanatory view showing a piping system of a brake device to which the configuration shown in FIGS. 2 to 5 can be applied. In the drawing, FR is the right front wheel, FL is the left front wheel, RR is the right rear wheel,
RL is left rear wheel, 15 _FR to 15 _RL is speed sensor, 30, 50, 7
0, 90, 102, 110 are control circuits, 26a, 26b, 36a to 36c, 46a
Reference numerals 46c, 66a to 66c, 85a to 85c, and 67 indicate changeover switches, 40 indicates a signal generated when the drive system is switched, and 60 indicates a signal obtained by detecting μ on the road surface.

Claims (1)

(57) [Claims] 1. An anti-skid control method for a wheel capable of switching a drive system between two-wheel drive and four-wheel drive,
When the drive system is switched from two-wheel drive to four-wheel drive, the anti-skid control is switched along with this switch so that all wheels simultaneously control the application and depressurization timings of their brake pressures. An anti-skid control method comprising: