JPS58199259A - Brake hydraulic pressure apparatus - Google Patents

Abstract

PURPOSE:To surely prevent any lock on rear wheels, by closing a hydraulic control valve when the rotational speed of the rear wheels get less than that of front wheels, by shutting off brake piping for the rear wheels, in an apparatus for preventing any lock on rear wheels during a braking action. CONSTITUTION:In a condition that braking action on the rear brake has been set bigger than that on the front brake in adrance, if a brake pedal 14 of an empty car is pushed down, to generate a brake hydraulic pressure, the braking power on rear wheel 2 becomes bigger than that on fron wheel 1, and the rotational speed of the rear wheel 2 becomes less than that of the fron wheel 1. Accordingly, the voltrages generated in DC dynanmo 27 and 26 provided on the reat wheel 2 and front wheel 1 differ from each other, then, a relay 43 is excited and a contact 43c is closed. As the result, the solenoid 42 of a hydraulic pressure control valve 30 is excited, and a path 34 is closed by a valve 36, and then the braking power of the rear wheel 2 is prevented from raising, while only the braking power of the front wheel 1 is raised, and only the front wheel 1 can be rapidly braked.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that limits rear wheel brake fluid pressure to prevent rear wheel locking.

An example of a conventional brake fluid pressure control device is shown in FIG. 1 (Japanese Unexamined Patent Publication No. 51-71467). That is, 1a and 1b are the front wheels, 2 t r 2 b
is the rear wheel, 6 is the brake pipe for the front wheel, 4 is the brake pipe for the rear wheel, and 5 is both brake pipes 3.

By controlling the hydraulic pressure of 4, the front wheels 11, 1b and the rear wheels 2&.

2b shows a hydraulic pressure control device that controls the rotational speed difference between the spool 7 and the case 6. When the sealing member 8 and the first coil 9 are excited, the direction toward the left in the figure (when the second coil 10 is attracted,
It consists of a spool 7 that is attracted to the right in the figure, a first coil 9, and a second coil 10. A protrusion 11.12 is fixed to the outer circumferential surface of the spool 7, so that when the spool 7 moves from side to side, it blocks one of the passages 14 and 15 communicating with the master cylinder 13. ing. The channel 14 , 15 is for supplying the chamber 17 , ta <= in the housing 6 with the hydraulic pressure which is increased in the master cylinder 13 by depression of the brake pedal 16 .

A circuit that excites both coils 9 and 10 is connected to a switch 22 and a power source 23 via a relay 21 that switches the opening and closing of a contact 19 and a contact 20 magnetized to N pole (or S pole). The switch 22 is connected to the master cylinder 16
This switch is turned on when the hydraulic pressure supplied from the hydraulic pressure reaches a predetermined value or more, and operates the hydraulic pressure control device 5. The relay 21 has an actuation coil 25 that magnetizes an actuation piece 24 for closing any of the contacts 19,20. Both ends of the actuating coil 25 are connected to dynamos 26a, 26b provided on the front wheels 11L, 1b, and dynamos 27a, 27b provided on the rear wheels 2&, 2b, so that when either of the generated voltages becomes high, In other words, when there is a difference in rotational speed between the front and rear wheels, the engine is activated.

When the brake pedal 16 is depressed to brake the vehicle, the hydraulic pressure supplied from the master cylinder 16 increases, causing each wheel 1a, 1b, 2a to be braked.

The brake device 2b is activated and braking of the vehicle begins.

When the hydraulic pressure exceeds a predetermined value and normal hydraulic pressure is supplied to the four wheels, the switch 22 is turned on and the illustrated electric circuit is closed. At this time, front wheels la, jb and rear wheel 2
If the rotational speeds of a and 2b are the same, the dynamo 26
1L, 26b, 27m.

27b generates the same voltage, no current flows through the actuating coil 25, and both contacts 19 and 20 are in the OFF state, so the spool 7 does not move, and the hydraulic pressure in both brake pipes 6 and 4 does not move. They will be the same, and the braking force will be the same.

When the rotational speed of the front wheels 1a, 1b becomes faster than that of the rear wheels 2a, 2b, the dynamo 26a of the front wheels 1a, jb,
26b becomes high, current flows from the front wheel side to the rear wheel side, and the left side of the actuating piece 24 is magnetized to the S pole and the right side to the N pole, and this (the accompanying actuation The contact 19 is closed by the displacement of the piece 24. Therefore, the second coil 1° is energized, and the spool 7 is attracted to the right side (-), firstly, the passage 15 is closed by the protrusion 12≦2, and then the passage 15 is closed by the protrusion 12≦2. As a result, the hydraulic pressure in the front wheel brake pipe 6 increases, and the braking force of the front wheels Ib increases.Therefore, the rotational speed of the front wheels 1a and tb decreases by one step, and the rear wheels When the rotation speed becomes the same as 2a and 2b,
The second coil 1.0 is no longer energized and the spool 7 returns to its original position.

Conversely, when the rotational speed of the rear wheels 2a, 2b becomes higher than that of the front wheels 11L, lb, the contact point 2o closes, the liquefaction of the rear wheel brake pipe 4 increases, and the rotational speed of the rear wheels 21L increases.

2b is strengthened, and the hydraulic pressure control device 5 continues to operate until the front wheels 1a and 1b reach the same speed (=).Switch 22
When the hydraulic pressure is less than a predetermined value, the hydraulic pressure control device 5 is disabled (-) to prevent unnecessary operation other than during braking. , 1b, the rear wheels 2a, and !b, if any one of the hydraulic pressure paths fails, the switch 22 is turned off to prevent the hydraulic pressure control device 5 from operating.

However, according to the conventional example (2), when a difference in rotational speed occurs between the front wheels and the rear wheels, the brake fluid pressure on the side with the faster rotational speed is released to brake the wheel with the faster rotational speed. Therefore, in order to increase the brake fluid pressure (2), in addition to the master cylinder 13, case 6 and coil 9. Since it was necessary to provide a hydraulic pressure increasing means consisting of a spool 7 equipped with a spool 7, the device becomes large-scale, and the weight and cost increase.1 The present invention solves these conventional problems ( = The brake piping for the rear wheels (two hydraulic pressure control valves are provided to limit the brake fluid pressure supplied to the rear wheels, and the rotational speed of the rear wheels is controlled by the rotational speed of the front wheels. and a rotation speed detection device that detects that the rotation speed of the rear wheels has become slower than that of the front wheels by lowering the brake fluid pressure of the rear wheels. Speed (two combinations, with the purpose of solving the problems of the former consort Consort).

The present invention will be described above based on the drawings.

2 and 3 are diagrams showing one embodiment of the present invention. First, to explain the configuration, ja and jb are front wheels, 2m and 2b are rear wheels, 6 is a front wheel brake pipe, 4 is a rear wheel brake pipe, 13 is a brake master cylinder, and 14 is a brake pedal. The brake piping 6 for the front wheels connects the master cylinder 13 and the brake devices of the front wheels 1a and 1b (not shown), and the brake piping 4 for the rear wheels connects the mask cylinder 16 and the brake devices of the rear wheels 2a and 2b. It is connected to a brake device (not shown), and a hydraulic pressure control valve 30 is interposed in the middle. Therefore, the rear wheel brake pipe 4 is connected to the hydraulic pressure control valve 6.
Pipe line 4a on the master cylinder 13 side from 0 and rear wheel 2a
, and a conduit 4b on the 2b side.

The hydraulic control valve 30 has a passage 34 between an inlet 32 and an outlet 66 opened in the main body 31, and a spring 3 in the passage 64.
5! At L, the Yakuchi 62 side (= the biased valve body 66 is interposed), and the body 61 (2 is the valve body 3 when the spring 65 & is compressed)
6 forms a seat 37 that closes the middle of the passage 34,
A bypass passage 38 that communicates the inlet 32 and the outlet 33 is formed in the valve body 66 . 321L is the entrance 32 and the passage 64
This is a notch for constant communication between the two. Bypass path 3
8 includes a throttle 39 and a ball valve 40 that closes the bypass passage 38.
A ball valve 40 (= is biased by a spring 35b to push the ball valve 40 (a rod 41 that opens the bypass passage 38 is faced from the second side. A solenoid 42 is made to face the valve body 36, When the solenoid 42 is energized, the valve body 36 is seated on a seat 37 (two seats).

The solenoid 42 is a terminal 43a of a normally open relay 46.

43b and a normally open switch 22 that turns on (-) when the brake fluid pressure of the master cylinder 16 exceeds a predetermined value.
The relay 43 connects the front wheel dynamos 261L and 26b, which will be described later, to the rear wheel dynamos 27a and 27b (only the current that flows (2) so that the contact 43c closes). and 4
3d is a coil for closing the contact 430. Each end of the coil 43 (l) is connected to the dynamo 26 & which is provided on the front wheels 1a, 1b.

26b, and a dynamo 27 provided on the rear wheels 2a and 2b.
1L and 27b, and when either of the generated voltages becomes high, that is, when there is a difference in rotational speed between the front and rear wheels (double excitation occurs, the dynamo 26a, 26b
, 27a, 27b may be at least one each for the front and rear wheels. Therefore, dynamo 26m, 26b,
27a, 27b, relay 43, electric circuit connecting these, solenoid 42, power supply 23, switch 22
, the relay 43, and the electric path connecting them correspond to the rotational speed detection device 44 of the present invention. The electromagnetic relay 4 mentioned above
3 (instead of two, dynamo 26 & , 26b and dynamo 2
71L.

It is also possible to use an electronic circuit that adjusts the voltage difference between the terminals 43a and 27b to close the terminals 43a and 43b.

Next (explain the two effects.

When the rotational speeds of the front wheels la, 1b and the rear wheels 2a, 2b are the same, the relay 46 is turned off between the dynamos 26a, 26b and the dynamometers 2f & 2b (because there is no voltage difference between the two). state (2), therefore, the solenoid 42 is not energized, the valve body 36 is in the position shown, the passage 34 is open, and the inlet 62 and the outlet 66 are in communication via the d passage 34. Therefore, when the brake ζ pedal 14 is depressed (2), the brake fluid pressure generated in the master cylinder 16 (2) is transferred to the conduit 4a, the inlet 6.
21 passage 34, exit 36. Tube) ¥! Rear wheel 2 via 4b
&, Brake device of 2b (2 supplied, rear wheel 2a,
Move part 2b. In addition, the brake fluid pressure generated by the master cylinder 16 (2) is supplied to the brake equipment of n'Nml & 1b via the front wheel brake piping 6 to brake the front wheels la, 1b. 1b
When the rotational speed of the rear wheels 2a and 2b is slower than that of the rear wheels 2a and 2b (-
Also, since the relay 43 is in the off state, the front wheel 1a.

The brake fluid pressure paths to the rear wheels 1b and 2&, 2b are the same. Also in this case, when braking (the second is the front wheel 11L).

Since the axle load of 1b increases, the front wheel ja, 1b is moved to the rear 42a.
, 2b.

In this embodiment, the front and rear braking distribution of the vehicle is set in advance so that the rear wheel side is large (2) as shown by the third line.
The rear wheels 2a and 1b do not lock first, and the rear wheels 2a
If the braking force of only 2b is limited, the rear wheels 21L, 2
b can be prevented from locking first.

In Fig. 3, line B is a line that shows the four-wheel time lock when the vehicle is loaded, and line C is a line that shows the four-wheel time lock when the vehicle is empty (lightly loaded). When the brake pedal 14 is depressed, the hydraulic pressure from the master cylinder 13 is supplied to each brake device of the front and rear wheels as described above, and the vehicle is braked.

When this braking force becomes large, even though the braking distribution on the rear wheels side is set to be large as described above, the amount of force applied to the rear wheels increases.

The braking force of the rear wheels 2b is larger than that of the front wheels 11L and lb, and the rotational speed of the rear wheels 2a and 2b is the same as that of the front wheels 1a.

It will be slower than that of 1b. This is shown in Figure 3 (point a at 2)
(split point). Then, the generated pressure of the rear wheel side dynamos 271L and 27b is transferred to the front wheel side dynamo 2.
Since the generated pressure is higher than that of 6a and 26b, relay 46
The coil 43d is energized, and the contact 43 and the terminal A 43 are
Between a and '43 b, the relay 43 is turned on. Further, since the switch 22 is already turned on when the brake fluid pressure in the front wheel brake piping 3 reaches a predetermined value, the solenoid 42 is energized by the power supply 23 and the valve body 36 is seated on the seat 37. Close passageway 34. Note that the rod 41 also moves to the right in the figure 5, then,
Since the rear wheel brake pipe 4 is cut off halfway, the rear wheel 2
&, 2b/7)' The braking force does not increase, and the front wheel 1 a +
Only the braking force of 1b continues to increase, and only the front wheels 11L and ib are rapidly braked.

When the point shown in FIG. 3 is reached, the rotational speed of the rear wheels 21L and 2b becomes higher than the rotational speed of the front wheels 11L and 1b, and each generated voltage also reaches the rear wheel side ≧ the front wheel side, and the relay 43 is turned off. become. Therefore, the solenoid 42 is also turned off, but there is a difference between the hydraulic pressure of the master cylinder 13 on the pipe line 4a side and the hydraulic pressure on the pipe line 4b side, and the former is larger, so the valve body 36
is in a sitting position, blocking the passage 34. However, spring 65. b by rod 4
1 is biased to the left in FIG.
9. Via the bypass path 38, it is gradually supplied to the rear wheel side,
In proportion to this, the braking force on the rear wheel side also increases, reaching point C in FIG. 3, C2. Then, by repeatedly opening and closing the ball valve 40, as shown in FIG. 3, the vehicle moves as close as possible to the line C indicating the four-wheel time lock.

The throttle 69 is configured so that when the ball valve 4o opens, the hydraulic pressure on the rear wheel side becomes equal to the hydraulic pressure in the master cylinder 13, and the rear wheel 21L
, 2b are prevented from locking.

Note that if the front wheel brake pipe 3 fails, the switch 22 is turned off (the control valve 30 does not operate).

Therefore, the hydraulic pressure of the master cylinder 16 can be constantly supplied to the rear wheels, so safety is sufficiently ensured. Also,
When the ball valve 40 is not used for the control valve 60 (2) When the rear wheel brake pipe 4 is shut off using only the valve body 36 (2)
It is possible to perform a four-wheel time lock. In this case, the characteristics are shown by the broken line in FIG. 3 (2).

4-7 show other embodiments.

In FIG. 4, 32 is its inlet, 36 is its outlet, 50 is a plunger, 501L is a radial hole, 50b is an axial hole, 5
1 is a valve body, 50c is a stopper, 50 (1 is a valve seat, 52 is a ball valve, 56 is a spring, 54 is a containment chamber, 55 is a piston, 56 is a washer of the piston 55, 57.58 is a spring, 59
is a washer of the plunger 50, and 42 is a solenoid, which constitute the hydraulic pressure control valve 30. The front and rear braking distribution is set the same as in the previous embodiment, and the containment room 5
The pressure PG of No. 4 (PGl is when the vehicle is lightly loaded, PO2 is when the vehicle is loaded) and the split point PS (PSl is when the vehicle is lightly loaded, PS2 is when the vehicle is loaded) are set to be equal.

When the voltage generated on the front wheel side becomes higher than the voltage generated on the rear wheel side, the solenoid 42 is energized, causing the ball valve 52 to close, thereby sealing a constant hydraulic pressure in the containment chamber 54.

When the containment pressure becomes constant, the distance of rightward movement of the piston 55 being pushed by this becomes constant (Fig. 4). Therefore, the restriction by the valve 51 is constant (-).

As shown in Fig. 5, the fluid pressure supplied to the rear wheels is limited, and as shown in Fig. Since the generated voltage≧the front wheel side generated voltage, the solenoid 42 is turned off.However, since there is a pressure difference between the containment chamber 54 pressure and the master cylinder 13 pressure, the ball valve 52 remains closed. However, the line d showing the braking force distribution between the front wheels 1a, 1b and the rear wheels 2a, 2b is as shown in Fig. 7 (the two ideal distribution lines are
Approaching reversal. In addition, the master cylinder 13 of the ball valve 52
side (2, aperture 69 in Fig. 21 (2) with a corresponding aperture,
Moreover, if the spring 56 is set strongly so that the ball valve 52 is opened even if there is a pressure difference between the containment chamber 54 pressure and the master cylinder 13 pressure, the front and rear The braking force distribution of the wheels is expressed as a line passing through points a, b, and c.

As explained above (2. The present invention; 2.at is a hydraulic control oil well provided in the brake piping for the rear wheels to limit the brake fluid pressure supplied to the rear wheels, and the rotational speed of the rear wheels. and a rotational speed detection device that detects that the rotational speed of the rear wheels has become slower than the rotational speed of the front wheels and instructs the operation of the hydraulic control valve, so that when the rotational speed of the rear wheels becomes slower than the rotational speed of the front wheels. , the brake fluid pressure on the rear wheel side is restricted to prevent the rear wheels from locking. Therefore, according to the present invention, since no means for increasing the brake fluid pressure is used, the scale of the device can be small. For this reason, Weight > 4, there is a movement that can reduce both cost and installation space.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the conventional example, Fig. 2 is an explanatory diagram showing an embodiment of the present invention, Fig. 3 is a graph showing the braking force distribution of Fig. 2, and Fig. 4 is an explanatory diagram of the present invention. An explanatory diagram showing other embodiments of
FIG. 5 is a graph showing the relationship between the rear wheel side hydraulic pressure and master cylinder hydraulic pressure in FIG. 4, FIG. 6 is a graph showing the relationship between the split point and the containment pressure, and FIG. It is a graph similarly showing braking force distribution. 1a, 1b...front wheel, 2a, 2b...rear wheel, 6.
...Brake pipe for front wheel, 4...Brake pipe for rear wheel, 26a, 26b, 27 turtle, 27b...dynamo, 6
0...Control valve, 44...Rotational speed detection device Patent applicant Nissan Motor Co., Ltd. agent Patent attorney Tetsuya Mori
Yoshiaki Naito, Patent Attorney Shimizu
Positive

Claims (1)

[Claims] The rear wheel brake pipe ζ is split into two parts, and the rear wheel side (2) has a hydraulic pressure control valve that limits the brake fluid pressure supplied, and detects when the rotational speed of the rear wheel has become slower than the rotational speed of the front wheel. A brake hydraulic pressure control device comprising: a rotational speed detection device for instructing the operation of the hydraulic pressure control valve.