JP2627618B2 - Hydraulic pressure control device for anti-skid device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vehicle for controlling a brake fluid pressure transmitted to a wheel cylinder of a wheel brake device in accordance with a rotational state or a skid state of a wheel of a vehicle or the like. The present invention relates to a hydraulic control device for an anti-skid device.

[Conventional technology and its problems]

This type of device is disposed between a master cylinder and a wheel cylinder of a wheel brake device, and receives a command from a control unit for evaluating a skid state of a wheel and controls a brake fluid pressure of the wheel cylinder. 2. Description of the Related Art A hydraulic control device for an anti-skid device having a hydraulic control valve is known. For example, if the wheels consist of a pair of front wheels and a pair of rear wheels, each front wheel and rear wheel is provided with a hydraulic pressure control valve, that is, four hydraulic pressure control valves are provided, each independently. There is no problem if you control the brake fluid pressure. Alternatively, there is no problem if one hydraulic pressure control valve controls the brake hydraulic pressure in common for both rear wheels according to the skid state of the rear wheel having the smaller rotation speed.

However, in the above case, three (three channels) or four
Since a single (four-channel) hydraulic pressure control valve is used, the entire apparatus (generally unitized with a reservoir or the like) is increased in size and weight. Furthermore, the cost of the hydraulic control valve is high because it is expensive.

Therefore, for example, in an X-type piping system (a piping that occupies the mainstream as a countermeasure against brake pipe failure), two hydraulic pressure control valves respectively control the brake hydraulic pressure of both front wheels, and each rear wheel has It has been proposed that the brake fluid pressure be controlled commonly by these fluid pressure control valves. However, at this time, when select high control is performed on the front and rear wheels of both diagonals (control based on the rotation behavior of the wheel having the higher friction coefficient μ between the tire and the road surface), the friction coefficient μ on the left and right road surfaces is increased. However, the brake control is performed without locking the wheel on the high μ side on the split road surface different from the above, but the wheel on the low μ side is locked and the directional stability of the vehicle is lost. Also, if the select low control is performed before and after both diagonals (control based on the rotation behavior of the wheel having the lower friction coefficient μ between the tire and the road surface), the wheels on the low μ side are also locked on the split road surface. Although the brake control is performed so that there is no such problem, the brake pressure of the high μ side wheel which is not locked originally or does not tend to lock is unnecessarily loosened, and the braking distance is unduly extended .

[Problems to be solved by the invention]

The present invention provides a fluid pressure control device for an anti-skid device capable of securing the directional stability of a vehicle even on a split road surface and securing sufficient braking force while reducing the weight of the device and reducing the cost as two channels. The purpose is to:

[Means for solving the problem]

According to the first aspect of the present invention, a pair of front wheels and a pair of rear wheels each having a diagonal pipe connection with each wheel cylinder; a first hydraulic pressure generation chamber of a master cylinder and one of the front wheels are provided. A first hydraulic pressure control valve disposed between the front wheel wheel cylinder and a brake hydraulic pressure of the front wheel wheel cylinder; a second hydraulic pressure generation chamber of the master cylinder and the other front wheel of the front wheels A second hydraulic pressure control valve disposed between the front and rear wheel cylinders for controlling brake hydraulic pressure of the front wheel cylinder; a wheel speed sensor provided for each of the front and rear wheels; A control unit for evaluating the wheel and skid conditions and issuing a command for controlling the first and second hydraulic pressure control valves; The rear wheel having a larger slip is determined to have a smaller coefficient of friction, and the wheel having a smaller slip is determined as having a larger coefficient of friction. Of the diagonal to which the rear wheel of the smaller friction coefficient belongs is determined as the braking pressure of the front and rear wheels to which the rear wheel of the smaller friction coefficient belongs. Select high control is performed between the front and rear wheels of the diagonal, and the braking pressure of the front and rear wheels of the diagonal to which the rear wheel having the larger friction coefficient belongs is selectively low controlled between the front and rear wheels of the diagonal. This is achieved by a hydraulic control device for an anti-skid device.

According to the second aspect of the present invention, a pair of front wheels and a pair of rear wheels each having a diagonal pipe connection with each wheel cylinder; a first hydraulic pressure generation chamber of a master cylinder and a wheel of one of the front wheels of the front wheels. A first hydraulic pressure control valve disposed between the front cylinder and a cylinder for controlling brake hydraulic pressure of a wheel cylinder of the front wheel; a second hydraulic pressure generation chamber of the master cylinder and a wheel cylinder of the other front wheel of the front wheels; A second hydraulic pressure control valve disposed between the front and rear wheels for controlling a brake hydraulic pressure of a wheel cylinder of the front wheel; a wheel speed sensor provided on each of the front and rear wheels; a skid of a wheel based on the wheel speed sensor A control unit for evaluating the condition and issuing a command for controlling the first and second hydraulic pressure control valves; and a hydraulic pressure control device for the anti-skid device. The one with the larger slip between the two front wheels is determined to be the one with the smaller friction coefficient, and the one with the smaller slip is determined as the one with the larger friction coefficient. The braking pressure of the front and rear diagonal wheels to which the front wheel with the smaller friction coefficient belongs is determined between the front and rear wheels of the diagonal, by determining that the coefficient of friction is smaller and that the wheel speed is higher is the larger of the friction coefficient. Selective control, wherein the braking pressure of the front and rear wheels of the diagonal to which the front wheel having the larger coefficient of friction belongs is selectively high controlled between the front and rear wheels of the diagonal, wherein the hydraulic pressure control for the anti-skid device is provided. Achieved by the device.

[Action]

According to the first invention, it is now assumed that the road surface is a split road surface, and of the two rear wheels with respect to the left and right road surfaces, the one with the larger slip has the smaller friction coefficient and the one with the smaller slip has the larger friction coefficient. Or, with respect to the left and right road surfaces, to determine that the lower wheel speed of the two rear wheels has the higher friction coefficient and the higher wheel speed has the lower friction coefficient, and as a result, If the right side is low μ and the left side is high μ, the brake pressure of the front and rear wheels of the diagonal to which the right rear wheel belongs is selectively high controlled between the front and rear wheels of the diagonal, so that the left front wheel on the high μ side The brake pressure of the diagonal to which the left rear wheel belongs is prevented from being unnecessarily loosened, and the brake pressure of the front and rear wheels of the diagonal to which the left rear wheel belongs is selectively low-controlled between the front and rear wheels of the diagonal so that the right side on the low μ side is To prevent the locking of the front wheel.

Further, according to the second aspect, on the split road surface, it is determined that the larger one of the two front wheels with respect to the left and right road surfaces has the smaller friction coefficient and the smaller one has the larger friction coefficient, or With respect to the left and right road surfaces, it is determined that the lower wheel speed of the two front wheels has the larger friction coefficient and the higher wheel speed has the smaller friction coefficient. Is high μ, the brake pressure of the front and rear wheels of the diagonal to which the right front wheel on the low μ side belongs is selected-low controlled between the front and rear wheels of the diagonal to prevent the locking of the front wheels, thereby preventing the front wheels from locking.
By selectively controlling the brake pressure of the front and rear wheels of the diagonal to which the left front wheel of the side belongs between the front and rear wheels of the diagonal, it is possible to prevent the brake pressure of the front front wheels from being unnecessarily loosened.

As described above, the steering and directional stability of the vehicle can be ensured, and the braking distance can be reduced as compared with the related art.

Further, in the first and second inventions described above, since only two hydraulic pressure control valves are used, the entire apparatus can be reduced in size, the overall weight can be reduced, and the apparatus cost can be reduced.

〔Example〕

Next, a hydraulic pressure control device for an anti-skid device according to a first embodiment of the present invention will be described with reference to the drawings.

First, the piping and wiring system of the entire apparatus of this embodiment will be described with reference to FIG.

In FIG. 1, the master cylinder (1) is a pedal (2).
And one of the hydraulic pressure generating chambers is connected to the right front wheel (6a) via a line (3), a three-position solenoid valve (4a) and a line (5).
Wheel cylinder (7a). The line (5) is further connected to the left rear wheel (11) through the line (13) and the pressure reducing valve (32b).
b) is connected to the wheel cylinder (12b).

The other hydraulic pressure generation chamber of the master cylinder (1) is connected to the pipeline (1
6) Connected to the wheel cylinder (7b) of the left front wheel (6b) via the 3-position electromagnetic switching valve (4b) and the conduit (17). The pipe (17) is further connected to the wheel cylinder (12a) of the right wheel (11a) via the pipe (15) and the pressure reducing valve (32a). The outlets of the switching valves (4a) and (4b) are pipes (60a) (60b)
Are connected to the reservoirs (25a) and (25b). The reservoirs (25a) (25b) are slidably fitted to the body and consist of pistons (27a) (27b) and weak springs (26a) (26b).
This reservoir chamber is connected to the suction ports of the hydraulic pumps (20a) (20b). The hydraulic pumps (20a) and (20b) are shown in a schematic diagram, and include a main body for slidably accommodating a piston, electromagnetic machines (22) and (22) for reciprocating the piston, and a check valve. The discharge port is connected to pipes (3a) (16a) branched from the pipes (3) and (16). The motor (22) is 2
Although they are illustrated, they are the same (one) and are commonly used for the hydraulic pumps (20a) and (20b).

Wheel speed detectors (28a) (28b) (29a) (29b) are disposed on the wheels (6a) (6b) (11a) (11b), respectively.
From these detectors, a panel signal having a frequency proportional to the rotation speed of the wheels (6a) ((6b) (11a) (11b) is obtained and applied as an input to a control unit (31) according to the present invention. The unit (31) generates control signals Sa and Sb motor drive signals Qo by a circuit configuration described in detail later.The control signals Sa and Sb are output from the three-position electromagnetic valve (4a) (4
It is supplied to the solenoid (30a) (30b) of b). The three-position solenoid valve (4a) (4b) has its solenoid (30a) (30
One of three positions A, B, and C is configured according to the magnitude of the current of the control signals Sa and Sb supplied to b). That is, when the currents of the control signals Sa and Sb are 0,
The first position A is set as the brake putting position. In this position, one master cylinder (1) and wheel cylinders (7
a) It is in communication with (7b). When the currents of the control signals Sa and Sb are low (hereinafter, the symbol "1/2" is used for convenience), that is, when a brake holding signal is generated, the second position B is set as the brake holding position. In this position, the distance between the master cylinder (1) and the wheel cylinders (7a) (7b) and the wheel cylinder (7a)
The communication between the (7b) side and the reservoir (25a) (25b) side is cut off. When the current of the control signals Sa and Sb is at a high level (hereinafter, the symbol "1" is used for convenience), the third position C is set as the brake release position. In this position, the master cylinder (1) side and the wheel cylinders (7a) (7b) side are shut off, but the wheel cylinders (7a) (7b) side and the reservoir (25
a) There is communication between the (25b) side and the brake fluid of the wheel cylinders (7a) and (7b) is stored in the reservoir (25a).
(25b) is discharged through conduits (60a) and (60b). The drive signal Qo generated when either the control signal Sa or Sb becomes "1" is supplied to the electric motors (22) and (22) as hydraulic pump driving means.

The wheels (6a), (6b), (11a), and (11b) are X pipes as described above. Next, the details of the control unit (31) will be described with reference to FIGS. .

The signals of the wheel speed detectors (28a) (29b) and (28b) (29a) are output from the wheel speed calculators (34a) (35a) and (34b) (35
b) from which a digital or analog output proportional to the wheel speed is obtained, which is the approximate vehicle speed signal generator (36a) (36b) and the low select circuit of the high select circuit (39a) (39b), respectively. (40a) and (40b).

The approximate vehicle speed generators (36a) and (36b) are configured in a known manner (for example, as disclosed in Japanese Patent Application Laid-Open No. 61-285164), and output wheel speed signals of front wheels and rear wheels of the same piping system. Then, a signal E representing the approximate vehicle speed is generated based on the temporal change of the larger one of the wheel speeds. This is supplied to the slip calculation circuits (37a) and (37b) and also to the skid signal generation circuits (41a) and (41b). The wheel speed signals obtained from the wheel speed detectors (29b) (29a) of the rear wheels are also supplied to the slip calculation circuits (37a) (37b).

The slip calculation circuit (37a) (37b) calculates the approximate vehicle speed E
And the left of the rear wheel speed V is calculated, and the outputs of the slip calculation circuits (37a) and (37b) are supplied to the slip comparator (38). The output λ _S of the comparator (38) is “1” when the output λ _L of the slip operation circuit (37a) is larger than the output λ _{R of} the other slip operation circuit (37b), and vice versa. Is a signal that becomes “0”, and this λ
_{The S} signal is supplied to the above-described high select circuit (39a) and low select circuit (40b), and the NOT gate (4
8) to the low select circuit (40a) and to the high select circuit (39b).

The outputs of the high select circuits (39a) (39b) and the low select circuits (40a) (40b) are output from the skid signal generation circuit (41).
a) is supplied to (41b), and the output signal from this is supplied to the logic circuits (42a) and (42b), and is also supplied to the logic circuits (42a) and (42b).
The output of b) is amplified by the amplifiers (43a) and (43b) to obtain the control signals Sa and Sb shown in FIG. The control signals Sa and Sb each take three levels, ie, “0”,
Take the level of “1/2” and “1” and output the signal of level “1/2”
The signals of EV ₁ , EV ₂ and the level “1” are represented as AV ₁ , AV ₂ .

The skid signal generation circuits (41a) and (41b) are configured in a known manner, receive the output of the high select circuit (39a) (39b) or the low select circuit (40a) (40b), and differentiate these temporally. An acceleration signal, a deceleration signal and the like are generated, and a slip signal and the like are generated in comparison with the approximate vehicle speed signal E. The high select circuit (39a) (39b)
Then, the front wheel speed calculators (34a) (35a) and (34b)
When the output of (35b) is received and the gate is opened by the output of the comparator (38), the signal with the higher wheel speed is selected and supplied to the skid signal generation circuits (41a) and (41b). Also, the low select circuit (40a) (40b)
When the output of the wheel speed calculators (34a) (35a) and (34b) (35b) is received and the gate is opened by the output of the comparator (38), the smaller one of these signals is selected and Is supplied to the skid signal generation circuits (41a) and (41b). The outputs of the skid signal generation circuits (41a) and (41b), that is, for example, the above-described acceleration signal, deceleration signal, slip signal, etc., are supplied to the logic circuits (42a) and (42b).
As is well known in this logic circuit, it is logically combined to determine whether the brake should be released, whether the brake should be held constant or increased, and this determination signal should be amplified by amplifiers (43a) and (43b). it is, and generates the AV _1, AV ₂ signal or EV _1, EV ₂ signal mentioned above.

Although not shown in FIG. 2, the control unit (31) further includes a motor drive circuit as shown in FIG. 3, which is an off-delay timer (44a) (4
4b), OR gate (45) and amplifier (46). That is, the above-mentioned output signals AV ₁ and AV ₂ are supplied to the off-delay timers (44 a) and (44 b), respectively.
The outputs of 4a) and (44b) are respectively supplied to an OR gate (45), and the outputs are amplified to become the motor drive signal Qo shown in FIG. Off delay timer (44a) (44b)
Is set longer than the maximum time between the currently occurring AV or AV ₂ signal and the next occurring AV ₁ or AV ₂ signal, which may occur during anti-skid control. Once becomes "1", it will continue this.

The configuration of the present embodiment has been described above. Next, this operation will be described.

Now, it is assumed that the right side of the road surface has a low friction coefficient μ and a low μ road surface, and the left side has a high friction coefficient and a high μ road surface. The wheel speed of the square wheel is determined by the wheel speed detector (28a) (29b) (28
b) The wheel speed calculation circuit (34a) (35a) (34
b) The wheel speed signals are generated via (35b), and these are approximate vehicle speed signal generation circuits (36a) (36b)
Are selected and the wheel speed signal having the higher wheel speed is selected in each piping system, and based on this time change, the approximate vehicle speed is calculated in a known manner, and the approximate vehicle speed signal generation circuit (36a ) (36b) to supply the approximate vehicle speed signal E to the slip calculation circuits (37a) (37b). The other input terminals of the slip operation circuits (37a) (37b) are connected to the left rear wheel (11b) and the right rear wheel (11
The wheel speed signal of (a) is supplied and this circuit (37a)
The slip amount is calculated in (37b) and supplied to the comparator (38).

However, now, since the right side of the road surface is a low friction road surface, the slip amount of the right rear wheel (11a) is larger, that is, λ _L and λ _R which are the outputs of the slip operation circuits (37a) (37b).
Of these, λ _R is larger, so that the output of the comparator (38) is λ _S “0”. This is supplied to the high select circuit (39a) and the low select circuit (40b). On the other hand, it is supplied to the low select circuit (40a) and the other high select circuit (39b) via the NOT gate (48). Since the supplied signal λ _{S is} “0”, the wheel speed detector (28a)
In one system of (28b), low select control is performed, and in the other system of the wheel speed detectors (28b) and (29a), high select control is performed.

That is, in one system, the opening speed of the right front wheel (6a) and the wheel speed of the right rear wheel (11b) are supplied to the low select circuit (40a), and since this gate is now open, the right front wheel In the wheel speed of (6a) and the wheel speed of the left rear wheel (11b), since the right front wheel (6a) is running on the low-grade road surface, the speed of this wheel is smaller and this is the low select circuit ( 40a) and is supplied to the next-stage skid signal generation circuit (41a). Therefore, the right wheel (6
The skid state of (a) is calculated in the skid signal generation circuit (41a), and a deceleration signal, an acceleration signal, a slip signal, or the like is generated according to the skid state, as is well known, which is a logic circuit (42a). ) To determine whether the brake in this system should be released, kept constant, or raised by a logical combination of the above signals, that is, a control signal Sa (AV ₁ , EV ₁
Consisting of). When you have to release the brake,
This level is "1", it generates AV ₁ comprising signal. When the brake should be held, the level is “1/2” EV ₁
Generate a signal. When the brake is to be further raised, for example, when the brake is to be slowly raised, it is changed to _one pulse of EV as is well known, and the filling, holding, and holding are repeated at predetermined intervals. Or the control signal Sa as is it consist signal AV ₁ and EV _1, which is supplied to the solenoid (30a) switching valve (4a) in FIG. 1, the switching valve in accordance with the signal level ( 4) Have A, B or C position for 4a). In accordance with each of these positions, the brake in the piping system is loosened, held constant, slowly raised, or rushed in. In the other piping system, the wheel speed signals of the left front wheel speed detector (28b) and the right rear wheel speed detector (29a) are supplied to the high select circuit (39b) whose gate is opened by the select high control, Of these, the signal with the higher wheel speed is selected and supplied to the skid signal generation circuit (41b). This circuit (41b) also generates a deceleration signal, acceleration signal, slip signal, etc. according to the skid state of the wheel with the higher wheel speed in the same manner as the above-mentioned skid signal generation circuit (41a). This is a signal that indicates whether the brake should be relaxed, held constant, slowly raised, or rushed, ie, AV, by logically combining in a logic circuit (42b).
_2, generates a control signal Sb consisting EV _2. This is supplied to the solenoid (30b) of the switching valve (4b) in FIG.
The switching valve takes the position of A, B or C according to the level of the signal, and depending on each position, the brake is rushed, held constant, or gradually raised. By comparing the slip amounts of the rear wheels (11a) and (11b) as described above, the one with the larger slip is determined to be a low friction road surface, and the front wheel (6b) to which the rear wheel belongs and the rear wheel (11b) are determined.
For (a), select high control is performed, so the rear wheel (11a) on a low friction road surface may show a locking tendency, but the front wheel (6b) on a high friction road surface is prevented from locking. . In the other piping system, the left rear wheel (11b) is judged to have high friction on the left road surface because the slip amount of the left rear wheel (11b) is small.
In this piping system, the select right control is performed, so that the right front wheel (6a) on the low friction road surface side is prevented from being locked. In this piping system, the rear wheel (11b) is also prevented from being locked. As described above, since both the front wheels (6a) and (6b) do not lock, the steering stability of the vehicle is guaranteed. Further, the braking distance can be made shorter than before. Note AV ₁ signal in the above, or AV ₂ signal that is, in any of the strains, the brake loosening signal is generated, the output of either the OFF-delay timer in FIG. 3 (44a) or (44b) is generated, This is supplied to an amplifier circuit (46) via an OR gate (45) and is amplified to generate a motor drive signal Qo. This is supplied to the motor (22) in FIG. 1, whereby the hydraulic pumps (20a) (20b) start driving. Accordingly AV ₁ or AV ₂
Causes the switching valve (4a) or (4b) to assume the C position, which causes the line (60a) or (60b)
The pressure fluid from the wheel cylinder of the wheel is discharged to the reservoir (25a) or (25b). This is sucked by the hydraulic pumps (20a) and (20b), and immediately the pipe (3a)
Or, it is sent to (16a) side. The signal AV ₁ or AV ₂ is a motor drive signal Qo as described above to occur is to occur, subsequently during anti-skid control is continuously driving signal
Qo is “1”. Therefore, the hydraulic pump is continuously driven.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the configuration other than the control unit (31) in FIG.
Only the configuration of the control unit (31) is different. Therefore, the control unit is indicated as (31). In FIG. 4, parts corresponding to those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

That is, in this embodiment, the wheel speed signals of the rear wheels are obtained from the wheel speed calculation circuits (35a) and (35b) by the speed signal comparator (4).
7) supplied to. The output Vs of the comparator (47) is obtained when the wheel speed of the left rear wheel (11b) of both rear wheels is higher.
That is, it is "0" when the output of the wheel speed signal calculation circuit (35a) is larger than the output of the other wheel speed signal calculation circuit (35b), and is "1" when the opposite is true. The output Vs of the comparator (47) is supplied to a high select circuit (39a) and a low select circuit (40b), and is supplied to a knot gate (4
The signal is supplied to the low select circuit (40a) and the high select circuit (39b) via 8).

As in the first embodiment, if the right side of the road is the low friction side and the left side is the high friction side, the wheel speed of the left rear wheel is higher, that is, the output of the wheel speed signal calculation circuit (35a) is higher. Is larger than the output of the other wheel speed signal calculation circuit (35b), and the output Vs of the comparator (47) becomes "0". This is supplied to the high select circuit (39a) for one piping system, but is "0", so that the gate remains closed, and to the other piping system, the low select circuit (40b). But this is also left as it is when the gate is closed. However, since it is inverted through the knot gate (48), the low select circuit (40a) and the high select circuit (39b) are opened, and the piping system to which the right front wheel (6a) and the left rear wheel (11b) belong is Select low control, left front wheel (6
The piping system of b) and the right rear wheel (11a) is select-high controlled. Low select circuit (40
a) In the right front wheel and the left rear wheel,
That is, the wheel speed of the front wheel (6a) running on the low friction road surface side is selected and supplied to the skid signal generation circuit (41a). In the other piping system, since select high control is used, the wheel speed of the left front wheel (6b) and the right rear wheel (11a), whichever has the higher wheel speed, that is, the wheel speed of the left front wheel traveling on a high friction road surface side Is selected and supplied to the skid signal generation circuit (41b). The following operation is exactly the same as that of the first embodiment, and the switching valves (4a) and (4b)
Control signals to the solenoids (30a) and (30b) are similarly formed. The effect is also the same as that of the first embodiment, and the stability of the steering of the wheels is ensured, and the braking distance can be further reduced as compared with the conventional case.

FIG. 5 shows a control unit (31A) according to a third embodiment of the present invention, in which parts corresponding to those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 2 showing the first embodiment, the slip amount of each rear wheel is calculated in the slip calculation circuits (37a) (37b) and compared with the comparator (38).
In the illustrated embodiment, the slip operation circuit (37a ') (37b')
The wheel speeds of the front wheels are stored in the wheel speed calculation circuit (34
a) The amount of front wheel slip is supplied from (34b) and is compared by a slip comparator (38), which generates an output λ _S ′. This λ _S ′ is “1” when the slip amount of the right front wheel (6a), that is, the output of the slip operation circuit (37a ′) is larger than the output of the other slip operation circuit (37b ′), and “λ” is the opposite. Unlike the first embodiment, this signal is supplied to a high select circuit (39a) via a knot gate (48) 'and is supplied to a low select circuit (40a). Is supplied directly. Then, for the other piping system, this output λ _S ′ is supplied directly to the high select circuit (39b), but is supplied to the low select circuit (40b) via a knot gate (48) ′. .

With the above configuration, if the right road surface is now on the low-friction side and the left road surface is on the high-friction side, the slip amount of the right front wheel (6a) is larger.
a ′) is larger than the output of the other slip calculation circuit (37b ′), and the output λ _S ′ of the slip comparator (38) is “1”.
The signal of level "1" is supplied to the low select circuit (40a), and the other pipe system is supplied to the high select circuit (39b).
Regarding the piping system of the front and rear wheels of the diagonal to which a) belongs, select-low control is performed and the other piping system, ie,
The piping system to which the left front wheel (6b) belongs is subjected to high select control.

It is clear that the locking of the front wheels (6a) and (6b) is also prevented in this embodiment, so that the steering stability of the vehicle is ensured and the braking distance is shortened.

FIG. 6 shows a control unit (31A ') according to a fourth embodiment of the present invention. Components corresponding to those in the above-described embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

In FIG. 4 showing the second embodiment, a speed comparator (4
In (7), the wheel speed signals of both rear wheels are
5a) Although the output Vs is supplied from (35b), in this embodiment, the speed comparator (47) is connected to both front wheels (6a) (6).
b) Wheel speed signal, that is, wheel speed calculation circuit (34a)
(34b) is supplied, and the output Vs 'is supplied to the high select circuit (39a) and the low select circuit (40b) of both piping systems via the knot gate (48)', and the low voltage of both piping systems is low. The signals are directly supplied to the select circuit (40a) and the high select circuit (39b). As in the example of FIG. 4, when the wheel speed of the right front wheel (6a) of one piping system is higher than the wheel speed of the other front wheel (6b), the output Vs' becomes "0" and vice versa. Becomes

In the above configuration, if the right road surface is on the low friction side and the left road surface is on the high friction side as in the above embodiment,
Among the two front wheels, the wheel speed of the front wheel (6b) running on the high friction road surface side is higher, and the wheel speed calculation circuit (34a)
Since the output of (34b) is larger than the output of (34b), the output Vs' of the comparator (47) becomes "1", which is supplied to the low select circuit (40a) in one piping system. In the other piping system, the high select circuit (39
b) supplied. As a result, the piping system to which the right front wheel (6a) traveling on the low friction road surface belongs is subjected to select-low control, and the left front wheel (6b) traveling on the high friction road surface side.
Is controlled by the high select. It is clear that the locking of the front wheels (6a) and (6b) is also prevented in this embodiment, the steering stability of the vehicle is guaranteed, and the braking distance can be shortened.

The embodiments of the present invention have been described above.
The present invention is not limited to these, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, the low friction side road surface is determined by comparing the slip amount or the wheel speed of both front wheels or both rear wheels, but instead of this, the lock pressure of both front wheels or both rear wheels is determined. as the low friction side road towards lower or control signals (AV _1, AV ₂ or EV _1, EV ₂₎ ahead in the direction which produced the low friction side road embodiment similar to select-low control and select the above-mentioned High control may be performed.

Also, for example, instead of the three-position three-boat electromagnetic switching valves (4a) and (4b) shown in FIG. 1, a supply valve (50) and a discharge valve (51) as shown in FIG. A device may be used. In FIG. 7, the switching valve (4
Although only one for a) is shown, the same is true for the other switching valve (4b).

That is, in FIG. 7, the supply valve (50) is a 2-position 2-port electromagnetic switching valve, and the discharge valve (51) is a 2-position 3-port electromagnetic switching valve. Each solenoid (50a) (51a)
Control signal Sa from a control unit (not shown)
₁ and Sa ₂ are supplied, and these control signals are changed from “0” to “1”.
When each level is "0", each valve (50) (51) takes the position of D and F, and connects both side pipes respectively. The control signals Sa ₁ , Sa ₂
Are at level “1”, the valves (50) and (51)
Take positions E and G. That is, the supply valve (50) shuts off the pipes on both sides, and the discharge valve (51) shuts off the master cylinder side and the wheel cylinder side, but connects the wheel cylinder side and the reservoir side with the pipe (60a). ). It is clear that the same effect as in the above embodiment can be obtained even by using such a valve device.

In the first and third embodiments, the slip amounts of both rear wheels or both front wheels are compared. However, the slip amounts may be compared.

Further, in the above embodiment, the slip or wheel speed of both rear wheels or both front wheels is compared, and when these are equal, nothing is mentioned, but at this time, select low control or select high control is performed. You may do so.

Further, in the above embodiment, to form an approximate vehicle speed signal, the higher one of the wheel speeds of the front and rear wheels of the same piping system is selected, and the approximate vehicle speed signal is formed in accordance with this temporal change. However, the approximate vehicle speed may be formed based on the wheel speeds of all the wheels and the highest wheel speed among them. Or, based on the wheel speed,
You may make it calculate from a vehicle body deceleration sensor.

The control on the split road surface having a low μ road surface on the right side and the high μ road surface on the left side has been described above. On the contrary, the control according to the present invention can also be performed on a split road surface having a high μ road surface on the right side and a low μ road surface on the left side. Holds.

For example, when the vehicle enters the right high μ road surface and the left low μ road surface from the right low μ road surface and the left high μ road split road surface, the select high control and the select low control of both diagonals are naturally switched.

〔The invention's effect〕

As described above, according to the hydraulic control device for an anti-skid device of the present invention, lock prevention control is always performed on both front wheels even on a split road surface, even though only two hydraulic control valves are used. In addition, since the lock control of the rear wheel on the high μ side is performed, the device is small and lightweight, and the braking distance can be further shortened compared to the conventional one while ensuring the steering stability of the vehicle.

[Brief description of the drawings]

1 is a piping diagram of a hydraulic control device for an anti-skid device according to a first embodiment of the present invention, FIG. 2 is a block diagram of a control unit in FIG. 1, and FIG. 3 is a motor in the control unit. FIG. 4 is a circuit diagram of a drive circuit, FIG. 4 is a block diagram of a control unit of a hydraulic control device for an anti-skid device according to a second embodiment of the present invention,
FIG. 5 is a block diagram of a control unit in a hydraulic control device for an anti-skid device according to a third embodiment of the present invention, and FIG. 6 is a control of a hydraulic pressure control device for an anti-skid device according to a fourth embodiment of the present invention. 7 is a block diagram of the unit, and FIG. 7 is a piping diagram showing a modification of the switching valve in FIG. In the figure, (31) (31) '(31A) (31A') ... Control unit (38) ... Slip comparator (39a) (39b) ... High select circuit (40a) (40b) ... Low select circuit (47) ... Speed comparator

Claims (2)

(57) [Claims] A pair of front wheels and a pair of rear wheels each having a diagonal pipe connection of each wheel cylinder; a first hydraulic pressure generating chamber of an aster cylinder and a wheel cylinder of one of the front wheels. A first hydraulic pressure control valve for controlling a brake hydraulic pressure of a wheel cylinder of the front wheel; disposed between a second hydraulic pressure generating chamber of the master cylinder and a wheel cylinder of the other front wheel of the front wheels. A second hydraulic pressure control valve for controlling a brake hydraulic pressure of a wheel cylinder of the front wheel; a wheel speed sensor provided on each of the front wheel and the rear wheel; evaluating a skid state of the wheel based on the wheel speed sensor; A control unit for issuing a command to control the first and second hydraulic pressure control valves; and a hydraulic pressure control device for an anti-skid device. The larger slip is determined as the smaller friction coefficient, the smaller slip is determined as the larger friction coefficient, or the lower wheel speed of the two rear wheels is determined as the smaller friction coefficient. Judging and judging that the higher wheel speed is the larger friction coefficient, the braking pressure of the front and rear wheels of the diagonal to which the rear wheel with the smaller friction coefficient belongs is selected high controlled between the front and rear wheels of the diagonal. And a brake control for the front and rear wheels of the diagonal to which the rear wheel having the larger coefficient of friction belongs is selected-low controlled between the front and rear wheels of the diagonal. 2. A pair of front wheels and a pair of rear wheels each having a diagonal pipe connection of each wheel cylinder; a pair of front wheels and a rear wheel disposed between a first hydraulic pressure generation chamber of a master cylinder and a wheel cylinder of one of the front wheels. A first hydraulic pressure control valve for controlling a brake hydraulic pressure of a wheel cylinder of the front wheel; disposed between a second hydraulic pressure generating chamber of the master cylinder and a wheel cylinder of the other front wheel of the front wheels. A second hydraulic pressure control valve for controlling a brake hydraulic pressure of a wheel cylinder of the front wheel; a wheel speed sensor provided on each of the front wheel and the rear wheel; evaluating a skid state of the wheel based on the wheel speed sensor; A control unit for issuing a command for controlling the second and second hydraulic pressure control valves; and a control unit for issuing an instruction to control the second hydraulic pressure control valve. The one with the larger slip is judged as the one with the smaller friction coefficient, and the one with the smaller slip is judged as the one with the larger friction coefficient, or the one with the lower wheel speed of the two front wheels is judged as the one with the smaller friction coefficient. The higher the wheel speed is determined to be the one with the larger friction coefficient, and the braking pressure of the front and rear wheels of the diagonal to which the front wheel with the smaller friction coefficient belongs is selected low controlled between the front and rear wheels of the diagonal, A hydraulic pressure control device for an anti-skid device, wherein the braking pressure of the front and rear wheels of the diagonal to which the front wheel having the larger friction coefficient belongs is selectively high controlled between the front and rear wheels of the diagonal.