JPS5849421B2 - anti-strain - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-skid control device, and in an actuator that uses booster pressure provided by a hydraulic brake booster as power pressure for the actuator, the booster pressure is reduced, and the actuator reduces the pressure of the rear wheel brake. This invention relates to an anti-skid control device that performs the following steps.

Conventional proportioning valves are provided with a device that proportionally reduces brake pressure between the mask cylinder and the rear wheel brake.

The present invention aims to provide an anti-skid control device which opens and closes a cut valve of an actuator by reducing the booster pressure and proportionally reduces the pressure supplied to the rear wheel brake.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram of an apparatus showing an embodiment of the present invention, showing detailed structures of an actuator 1 and a proportional pressure reduction device 2 for booster pressure.

In the figure, 3 is the brake pedal, 4 is the mask cylinder,
5 is a front wheel brake, and 6 is a rear wheel brake.

Further, 7 is a hydraulic brake booster, 8 is a reservoir tank, 9 and 10 are check valves, 10' and 11 are orifices, 12 is a sensor, and 13 is a computer, all of the above members being known.

Reference numeral 14 designates a control valve that operates in accordance with an operation command signal from the computer 13, the detailed structure of which is shown in FIG.

15, 16, and 17 are brake fluid system piping, 18 to 35 are power hydraulic system piping, and dotted lines 36 to 35 are pipings for the power hydraulic system.
39 indicates an electric wire.

In the annotuator 1, 40 is a pressure reducing piston;
1 is a power piston, 42, 43 are bypass valve pistons, 44 is a small power piston, 45, 46 are ball valves, 47, 48, 49 are valve seats, so, s
i is the spring, 52 is the population from mask cylinder 4,
53 is an outlet to the rear wheel brake 6, and 54.55 is an inlet/outlet for power hydraulic pressure.

Further, in the pressure reducing device 2, 56 is a body, and 57 is fixed to the body 56 by a plug.

A spool valve piston 58 is slidable within the body 56.

59 is a spring, 60 is an inlet from the pump 61, 62
is an outlet to the actuator 1, and 63 is an outlet to the reservoir 8.

FIG. 2 is a detailed sectional view of the control valve 14, where 64.65 is a solenoid, 66.67, 68.69 are pistons, and 70.7
1 is a ball valve, 72, 73, 74.75 are valve seats, and 76, 77 are springs.

78 and 79 are orifices, and the orifice 79 has a small throttle hole 80 to restrict the flow of oil.

Further, the orifice 78 is used to adjust the flow rate to match the characteristics of the equipment.

81 is the population from the pressure reducing device 2, 82 is the actuator 1
83 is an outlet to the reservoir 8, said 38, 39
is the wire from the computer 13.

When both the solenoids 64 and 65 are off, the flow is as shown in the drawing: inlet 81 → chamber 84 → passage 85 → chamber 86 → outlet 82, and when solenoid 64 is off and solenoid 65 is on, population 81 → chamber 84 → Passage 85 → Chamber 87 → Throttle hole 80
→ Passage 88 → Connects with exit 82.

Also, when the solenoid 64 is on and the solenoid 65 is off, the communication goes from the outlet 82 to the chamber 86 to the passage 85, and from the chamber 89 to the outlet 83, and when both the solenoids 64 and 65 are on, the outlet 82 →
It communicates with passage 88 → throttle hole 80 → chamber 87 → passage 85 → chamber 89 → outlet 83.

Next, Fig. 3 is a characteristic diagram showing the relationship between the mask cylinder pressure PM and the adjusted pressure PR after reducing the booster pressure (partially booster pressure PR), and Fig. 4 is a characteristic diagram showing the relationship between the mask cylinder pressure PM and the adjusted pressure PR after reducing the booster pressure. It is a characteristic diagram showing the relationship with pressure Pw.

Now, when the brake pedal 3 is depressed during normal braking, the pressure in the hydraulic brake booster 1 increases, the mask cylinder 4 is pressurized, and the front wheel brake 5 is pressurized.
is activated, and the rear wheel brake 6 is connected to the pipe 16 → inlet 52 → chamber 90 → chamber 100 → passage 91 → chamber 92 → outlet 5.
3 → Actuates via actuator 1 like piping 17.

On the other hand, since the pressure is increased by the hydraulic brake booster 7, the pressure also increases in the pipes 19 and 22 at the same time.
It is supplied to the chamber 96 of the actuator 1 via → chamber 95 → outlet 62 → piping 26 → piping 27, and further supplied to the chamber 97 of actuator 1 via piping 30 → control valve 14 → piping 31.

Booster pressure P of this hydraulic brake booster 7
Assuming the relationship between B and MJ pressure PM as PB=a-PM+b...
Assuming (2), this diagram is represented by A in Figure 3, and the pressure increases in the relationship from Q to C on this diagram.

When the booster pressure PB approaches point C, that is, P1 (here, the cross-sectional area of the large diameter part of the piston 58 of the pressure reducing device 2 is set to A4, the cross-sectional area of the small diameter part is set to A5, and the load of the spring 59 is set to 82), From the relationship A4> (A4-A5), the piston 58
gradually moves to the left and finally reaches the edge portion 9 of the body 56.
8 and the edge portion 99 of the piston 58 contact, and the chambers 93 and 9
5, that is, communication between the population 60 and the exit 62 is cut off.

Booster pressure PM=P1 at this time is {P1XA,=82}
It is determined from the relational expression.

Furthermore, the booster pressure PB rises from P1, and the pressure PB in the chamber 93 increases.
, the pressure PR in the chamber 95 is {PRXA4<PBX(A4
A5)+S2}, the piston 58 moves to the right,
Since the edge parts 98 and 99 are separated and the chambers 93 and 95 are communicated with each other, the pressure PR in the chamber 95 increases, and { P RX A4
>P B .

Therefore {PRXA42PBX(A4 As)+82)
According to the relational expression PR is reduced in pressure from PB and is supplied to the chambers 97 and 96 of the actuator 1.

Therefore, by substituting the above equation (■) into this equation, we get PR and P
The relationship with M is obtained.

This diagram is represented by the mouth in FIG.

Here, for the sake of simplicity, in the formula
, {bX(1-I)+51}=h A4 A4 PR=g-PM10h ・・・・・・・・・・・・・・・
■It becomes.

As mentioned above, when booster pressure PB becomes more than P1,
The adjustment pressure PR supplied to the chamber 97 of the actuator 1 is
It rises like the line indicated by the mouth in Figure 3.

Here, in FIG. 1, the effective pressure-receiving cross-sectional area of the seal contact portion between the ball valve 45 and the valve seat 47 of the actuator 1 is A1, the cross-sectional area of the pressure reducing piston 40 is A2, the cross-sectional area of the power piston 41 is A3, and the cross-sectional area of the spring 50 is A3. Assuming the load is 81, in Fig. 3, P R X A3 = ( P
M 10A2) 10Ss...'...Draw the line C of the relational expression ■, let the intersection of the line entrance and the line C be E, and let PM at this time be Po and PR be P2.

Here PR<P2 (including PB<P1) or PM<Po
When {(PRXA3),>(PMXA2)+81}
Therefore, the ball valve 45, the pressure reducing piston 41, etc. of the actuator 1 maintain the state shown in FIG. 1, and the ball valve 45 and the valve seat 47 are separated.

However, when P B > P 2 or PM > PO, (
(PRXA3) <PMXA2) +81}
Therefore, the pressure reducing piston 40 and the power piston 4
1 moves to the left, and the ball valve 45 is pressed against the valve seat 47 by the spring 50, so that the chambers 90 and 1
00, i.e. mask cylinder 4 and rear wheel brake 6
Communication with is cut off.

When the pressure further increases, even if PR<PM, Aa>At
If the increase in the force of PRXA3 is set to be much larger than the increase in the force of PMXA1, then
At the hydraulic pressure PW, PM, PR {(PRXA3)
+(PWXAI)>(PWXA2)+(PMXA1)+S1}, the power piston 41 and the pressure reducing piston 4
0 moves to the right, and the ball valve 45 is pushed up and away from the valve seat 47, so the pressure in the chamber 90 is reduced to the pressure in the chamber 100.
is introduced into the chamber 100, and the pressure Pw in the chamber 100 increases, but Pw is
(PRX A3) 10 (P wX A1) <(
When the pressure rises to Pw1A2)+(PM+AI)+st), the pressure reducing piston 40 and the power piston 41 move to the left again, and the chambers 90 and 100 are shut off by the ball valve 45 and the valve seat 47.

When PR and PM further increase, the above-mentioned operation is repeated, and Pw is reduced with respect to PM, resulting in a relationship as shown in FIG. 4.

In other words, it has the same characteristics as a proportioning valve (PV).

PR at this time. P.M. The relational expression with PW is { (P
R XA3 ) + ( PWXAI ) = ( PWXA
2) +(PMXAI) +St), and substituting the equation (2) into this equation yields, and this relational equation is expressed as a two-line diagram in FIG.

In Fig. 3, draw a H line diagram of PRxA32PMXA1...■, draw a line diagram (represented by the following formula) so that this intersects point E, and use the formulas in Figures 3 and 4 as well as From the formula ■, the slope of the formula ■ is Δ. Therefore, if the dimensions and specifications are determined so that {KL:LN=GJ:GH}, the characteristics described above can be obtained.

Next, a description will be given of the time when normal braking is released.

When the brake pedal 3 that has been depressed begins to return, the booster pressure PB decreases and the pressure in the chamber 93 decreases, so the piston 58 of the pressure reducing device 2 moves further to the left, and the passage 10 inside the piston
1 and the chamber 102 are communicated, and the oil in the chamber 95 flows through the passage 94 → the passage 101 → the chamber 102 → the outlet 63 → the pipe 33 → the check valve 10 →
Since it is discharged to the reservoir 8 via the pipe 34 → pipe 35, the chamber 9
(The check valve 10 and orifice 10' are provided so that the pressure flowing through the pipe 32 during anti-skid operation, which will be described later, does not affect the pressure reducing device 2.)

When the pressure in the chamber 95 decreases, the piston 58 returns to the right and opens the passage 1.
01 and chamber 102 are blocked, but PB, that is, chamber 93
When the pressure in chamber 95 decreases, passage 101 and chamber 102 are communicated, and the pressure in chamber 95 decreases again. By repeating this, as PB decreases, PR decreases, and of course PM also decreases, so PR
and PM decrease almost along the line in Figure 3.

Furthermore, when PR, that is, the pressure in the chamber 97, decreases, PM also decreases, but since PM>Pw, the pressure in the chamber 10 of the actuator 1 decreases.
0 to the chamber 90, but the pressure reducing piston 40 and the power piston 41 move to the left due to the balance of {PRxA32PwXA2}, so Pw decreases as PR decreases.

P B, < P 2 ( P y1 < P o ),
That is, when PM further decreases after passing point E, PM<Pw and the ball valve 45 is pushed open by the hydraulic pressure in the chamber 100.
Since the current flows to 0, Pw also decreases.

At the same time, the decompression piston 40 and the power piston 41 begin to return to the right, finally pushing up the ball valve 45,
Communication between chambers 90 and 100 is maintained.

Next, when PB<P1, that is, point C is passed, and PB further decreases, PB becomes less than PR, so the check valve 9 is pushed open and the chamber 95 is opened.
pressure flows into the pipe 21 and becomes approximately PB=PR, so the piston 5B of the pressure reducing device 2 is returned to the right by the spring 59.

Therefore, everything is returned to the state shown in FIG.

Next, during anti-skid braking, when the rear wheels are about to lock up due to the rear wheel brake 6 during the aforementioned braking period, the computer 13 turns on the solenoid 64.
When a signal is generated and the solenoid 64 is energized, the piston 66 is pushed to the left in FIG. is blocked, and the outlet 83 and passage 85 communicate with each other.

That is, the pressure reducing device 2 and the chamber 97 of the actuator 1 are cut off, and the chamber 97 and the reservoir 8 are communicated with each other, so that the pressure in the chamber 97 decreases.

For this reason, the pressure in the decompression chamber 100 pushes the decompression piston 4 and the power piston 41 to the left, so that the ball 45
is pressed against the valve seat 47 by the spring 50,
Since the volume of the chamber 100 increases, the pressure of the chamber 100 decreases, and the braking of the rear wheel brake 6 is weakened.

Next, when the solenoid 65 is energized by a command from the computer 13, the piston 68 is pushed to the left, and the ball 71 is separated from the valve seat 15 and pressed against the valve seat 74, so that the passage 85 and the chamber 86 are cut off. As a result, the passage 85 and the passage 88 are communicated with each other, and the oil in the chamber 97 passes through the small passage 80 of the orifice 79, so that the decompression speed becomes slow.

Next, when the rear wheel is unlocked, the solenoids 64 and 65 are de-energized by a signal from the computer 13.
Since the state shown in FIG. 2 is reached, the chamber 97 is pressurized again.
The power piston 41 and the decompression piston 40 are pushed to the right, the pressure in the decompression chamber 100 is increased, and the braking of the rear wheel brake 6 is strengthened.

Next, when the solenoid 65 is energized, the oil passes through the orifice 79, which slows down the rate of pressure increase.

Repeat the above steps to perform anti-skid braking.

Next, when the power pressure decreases due to a defect in the pump 61 or the like during a power pressure deficit, the pressure reducing device 2 returns to the state shown in FIG. 1 as described above, the pressure in the chambers 97 and 96 of the actuator 1 decreases, and the The ball 45 is pressed against the valve seat 47 by the differential pressure between PM and Pw (which also promotes this action), and the ball 46 is pressed against the valve seat 49 by the spring 51 (and the differential pressure between PM and Pw also promotes this action). Since it is separated and crimped to the valve seat 48, the mask cylinder 4 → pipe 16 → population 52 → chamber 90 → passage 103 → chamber 10
4→hole 105 of piston 42→chamber 106→outlet 53→pipe 17, communication is ensured, and braking is guaranteed.

As explained in detail above, the present invention improves air removal from the brake fluid by reducing the number of devices between the mask cylinder and the wheel brake (removing p and v).
The amount of liquid consumed by the mask cylinder (brake pedal stroke) can be reduced.

In addition, since a spool valve is used for the booster pressure reducing device, the conventional P. Compared to ■, there is no need for cups, stickers, etc.
The number of parts can be reduced, and problems such as scuffing of cups and seals, clogging with rubber powder, etc. do not occur.

In addition, the pressure on the wheel brake side is reduced by the slight opening and closing of the actuator's cut valve, so the ball valve and valve seat of the cut valve are either closed or only slightly opened, so the pressure is reduced immediately during anti-skid. is carried out, has good responsiveness (no delay in operation due to valve lift between the valve seat and ball valve), and
Mask cylinder pressure fluctuations are reduced (pedal shock is reduced).

Note that instead of the pressure reducing device 2, it is also possible to use a G valve (a load sensing valve whose turning point changes depending on the load) and a G valve whose conversion point changes depending on the deceleration generated in the vehicle body during braking.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of an anti-skid control device showing an embodiment of the present invention, Fig. 2 is a detailed cross-sectional view of the essential parts, and Fig. 3 shows the mask cylinder pressure PM and the booster pressure after it is reduced by the deceleration device. Figure 4 is a diagram showing the relationship between . It is a diagram showing the relationship between mask cylinder pressure PM and wheel brake cylinder pressure Pw. Explanation of the main parts of the figure, 1...actuator,
2... Pressure reducing device, 3... Brake pedal, 4... Mask cylinder, 5... Front wheel brake, 6... Rear wheel brake. , 7... Hydraulic brake booster, 8... Reservoir tank, 9, 10...
... Check valve, 13 ... Computer, 14.
...Control valve, 45.46...Ball valve.

Claims (1)

[Claims] 1. A brake mask cylinder, one or more rear wheel brakes that perform a braking action using braking pressure from the cylinder, which is disposed between the brake mask cylinder and the rear wheel brake, and adjusts the rear wheel brake according to the skid state of the wheel. an actuator that increases or decreases the braking pressure of the brake; a control unit that issues a pressure increase/decrease command signal to the actuator; a hydraulic brake booster that operates the brake mask cylinder in accordance with the force applied to the brake pedal; and a hydraulic brake booster that applies power pressure to the booster. In a brake system that supplies a pressure source and uses the working pressure of the hydraulic brake booster as the working pressure of the actuator, the brake system is arranged and set between the hydraulic brake booster and the actuator. When the operating pressure is lower than the operating pressure, the outlet operating pressure is increased at the same rate of increase as the population operating pressure, and when the population operating pressure exceeds the set operating pressure, the increase rate of the outlet operating pressure is set to be greater than the increase rate of the population operating pressure. An adjusting device is provided in the actuator to reduce the braking pressure when the braking pressure is lower than the set braking pressure by the action of the outlet working pressure of the adjusting device supplied to the actuator, and the brake mask cylinder and the rear wheel brake are provided in the actuator. The outlet braking pressure of the actuator is increased at the same rate of increase as the artificial braking pressure by opening the opening/closing valve that opens and closes the communication with the actuator, and when the artificial braking pressure of the actuator exceeds the set braking pressure, the opening/closing valve is opened. An anti-skid control device comprising means for opening and closing a valve to make the rate of increase in the outlet braking pressure of the actuator smaller than the rate of increase in the inlet braking pressure.