JPS6153263B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic power brake for automobiles and other vehicles equipped with two or more hydraulic brake systems.

Conventionally, in order to obtain a boost function that reduces the force required to press the brake pedal, an anti-skid function, and a function that optimizes front and rear wheel brake force distribution, etc.
Each had a separate mechanism for each function. That is,
For the first function, a booster such as a booster that uses engine negative pressure or a booster that uses pump oil pressure is used, and for the second function, it is necessary to Anti-skid devices are used that use negative pressure or hydraulic actuators to temporarily reduce brake oil pressure when skidding is about to occur; A proportioning valve or a deceleration control type pressure regulating valve was used to reduce and adjust the oil pressure.
As a result, the entire brake system becomes complicated, which is disadvantageous in terms of space, and the loss of stroke caused by each mechanism increases, making it necessary to use a large master cylinder, and other problems cannot be avoided. In addition, piping, joints, etc. are also complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hydraulic power brake in which the individual functions of the conventional brake system can be easily combined organically, thereby reducing the size of the entire device.

To this end, the present invention provides a hydraulic converter that adjusts the hydraulic source hydraulic pressure (hereinafter referred to as power hydraulic pressure) in accordance with the master cylinder hydraulic pressure, and a hydraulic converter that adjusts the hydraulic source hydraulic pressure (hereinafter referred to as power hydraulic pressure) in accordance with the master cylinder hydraulic pressure, and a hydraulic converter that adjusts the hydraulic pressure source hydraulic pressure (hereinafter referred to as power hydraulic pressure) in accordance with the master cylinder hydraulic pressure. A closing part that closes the front wheel brake system to the front wheel brake system and the rear wheel brake system to the rear wheel cylinder at the intermediate part and separates them into the tandem master cylinder side and the wheel cylinder side, and the brake hydraulic pressure of the separated wheel cylinder side is connected to the power source. The pressure is increased according to the oil pressure and applied to the wheel cylinder.

Furthermore, in a specific example of the present invention, a hydraulic power brake is constructed by adding an anti-skid control section that temporarily reduces the brake hydraulic pressure when the wheels lock or are about to lock. .

Hereinafter, the present invention will be explained based on illustrated embodiments.

In the figure, reference numeral 10 indicates a tandem master cylinder, which generates master cylinder hydraulic pressure by depressing the brake pedal 11, supplies the master cylinder hydraulic pressure to the front wheel cylinders 12, 12 through the front brake system 13, 14 on the one hand, and supplies the master cylinder hydraulic pressure to the front wheel cylinders 12, 12 through the front brake system 13, 14 on the other hand. Master cylinder hydraulic pressure is supplied to wheel cylinders 15, 15 through rear brake systems 16, 17. P is an oil pump.

The hydraulic converter 20 includes a piston 23 having a large diameter part 23a and a small diameter part 23b that slide in a large diameter cylinder 21 and a small diameter cylinder 22, respectively, and a master cylinder hydraulic pressure is applied to the end face of the small diameter part 23b. End wall of small diameter cylinder 22 and small diameter portion 23b
The piston 23 is urged toward the large diameter portion 23a (left side in the figure) together with a spring 24 inserted between the piston 23 and the spring 24 inserted between the piston 23 and the spring 24. A drain port 25 is opened in the end wall of the large diameter cylinder 21, and this drain port 25 is connected to the large diameter portion 23.
A slit 23d is provided at the tip of the valve body 23c so that a slight flow of hydraulic oil occurs when the valve body 23c is completely closed. The discharge oil pressure of the pump P is introduced into the large diameter cylinder 21, and when this power oil pressure becomes larger than the value corresponding to the master cylinder oil pressure and the leftward pressing force by the spring 24, the piston 2
3 to the right, and move the valve body 23c to the drain port 2.
5 and opens, lowering the power hydraulic pressure, and conversely, when the power hydraulic pressure is lower than the value corresponding to the pressing force to the left, the piston 23 is moved to the left, and the valve body 23c is brought closer to the drain port 25 and closed. ,
The power hydraulic pressure is increased, and as a result, the power hydraulic pressure is controlled in accordance with the master cylinder hydraulic pressure and the pressing force of the spring 24. Note 26a, 26b
is a seal ring.

The closing parts 30, 40 (The following configurations are the same for both the front system and the rear system, so only the front system will be described, and the rear system (only the numbers are written in parentheses) are the large diameter cylinder 31 (41) and the small diameter cylinder. 32 (42), the large diameter portion 33a slides inside each
(43a) and a small diameter portion 33b (43b).
There is a power hydraulic passage 33 (44) on the end face of 3a).
, and acts to urge the piston 33 (43) to the right in the figure. On the other hand, a spring 35 (45) is disposed inside the small diameter cylinder 32 (42), urging the piston 33 (43) to the left in the figure, and a valve seat 36 (45) is provided on the end wall of the small diameter cylinder.
6) is provided, and a valve body 33c provided at the end of the small diameter portion 33b (43b) of the piston 33 (43).
When the piston 33 (43) moves to the right, (43c) seats on the valve seat 36 (46) and blocks off between the oil passages 13 and 14 of the front brake system (and between the oil passages 16 and 17 of the rear brake system). function to do so. Note that 38a, 38b (48a, 48b) are seal rings.

The anti-skid control section 50 (60) includes an actuator 51 (61) and an electromagnetic switching valve 70 (80) that controls the actuator 51 (61).

The actuator 51 (61) includes a piston 54 (6) having a large diameter portion 54a (64a) and a small diameter portion 54b (64b) that slide inside a large diameter cylinder 52 (62) and a small diameter cylinder 53 (63), respectively.
4), the small diameter cylinder 53 (63) communicates with the oil passage 14 (17) of the front (rear) brake system, and the large diameter cylinder 52 (62) is connected to power hydraulic pressure as appropriate via the electromagnetic switching valve 70 (80). is guided.
Note that 55a, 55b (65a, 65b) are seal rings and 56 (66) return springs.

Further, the electromagnetic switching valve 70 (80) is connected to the cylinder 71.
(81), a plunger 73 (83) that can slide within the cylinder 71 (81) and is biased in one direction by a spring 72 (82), and a cylinder 71 (81).
1) Drain port 7 opened in one end wall of
4 (84) and this drain port 74 (84)
A valve body 73a (83a) is provided on the plunger 73 (83) so that it can be seated on the plunger 73 (83), and a port 75 is opened in the other end wall of the cylinder 71 (81) and receives power hydraulic pressure through the oil passage 34 (44). (85) and
A valve body 73b (83b) provided on the plunger 73 (83) so as to be seated in the port 75 (85);
The solenoid coil 76 (86) is driven by the anti-skid control circuit 90 when the wheels are locked or when the wheels are about to lock. Note that 73c (83c) is an oil groove. When the coil 76 (86) is not activated, it is in the state shown in the figure, and the plunger 73 is moved by the spring 72 (82).
(83) is located at the bottom of the figure, drain port 74
(84) is closed, port 75 (85) is open and acts to supply power hydraulic pressure to the large diameter cylinder 52 (62) of actuator 51 (61), and when coil 76 (86) is actuated, spring 72 (8
2), the plunger 73 (83) moves to the upper position in the figure, closes the port 75 (85), opens the drain port 74 (84), and closes the large diameter cylinder 52 ( 6
2) It acts to remove hydraulic oil from.

Next, the operation of the hydraulic power brake of the present invention having the above-described structure will be explained.

The large-diameter cylinder 21 of the hydraulic conversion unit 20 is constantly supplied with hydraulic source hydraulic pressure, that is, power hydraulic pressure, and as described above, when the power hydraulic pressure is larger than the value corresponding to the leftward pressing force by the spring 24, the piston 2
3 to the right, and move the valve body 23c to the drain port 2.
5, the power oil pressure will decrease, and conversely, when the power oil pressure becomes smaller than the above value, the spring 2
4 moves the piston 23 to the left, brings the valve body 23c closer to the drain port 25 to close this port, increases the power oil pressure, and as a result, adjusts the power oil pressure to one corresponding to the pressing force of the spring 24.

This adjusted power oil pressure is transmitted to the large diameter cylinders 31, 4 of the closing parts 30, 40 through oil passages 34, 44.
1 of the actuators 51, 61 via the switching valves 70, 80.
62 is also supplied.

However, when the brake pedal 11 is not depressed, the master cylinder oil pressure is not applied to the small diameter cylinder 22 of the oil pressure converter 20, so the power oil pressure is low, and the pistons 33, 43 of the closing parts 30, 40 and the pistons of the actuators 51, 61 54,6
4 to the right in the figure.
Therefore, the front and rear wheel cylinders 12,
Brake oil pressure is not generated at 12, 15, and 15.

When the master cylinder hydraulic pressure is generated by depressing the brake pedal 11, this hydraulic pressure is transmitted to the small diameter cylinder 22 of the hydraulic pressure converter 20 through the oil passage 16.
The piston 23 is pressed to the left in the figure to adjust the power oil pressure to a high oil pressure corresponding to the master cylinder oil pressure. This high power oil pressure is led to the large diameter cylinders 31, 41 of the closing parts 30, 40, and presses the pistons 33, 43 to the right in the figure.
The valve bodies 33c and 43c are seated on the valve seats 36 and 46, and the front brake system is connected to the oil passages 13 and 14.
Further, the rear brake system is separated into oil passages 16 and 17, respectively. At the same time, the power hydraulic pressure is applied to the pistons 5 of the actuators 51 and 61 via the switching valves 70 and 80.
4, 64 to the right to increase the brake oil pressure in the small diameter cylinders 53, 63, and apply braking to the vehicle by the front and rear wheel cylinders 12, 12 and 15, 15. The brake oil pressure in this case is the piston 54 of the actuator 51, 61,
64 large diameter portions 54a, 64a and small diameter portions 54b,
64b and the ratio of the master cylinder oil pressure to the power oil pressure and is supplied to each wheel cylinder, a large braking force can be obtained even if the depression force on the brake pedal 11 is small. Further, the relationship between the braking forces of the front brake and the rear brake is determined by the ratio of the large diameter portion and the small diameter portion of the piston of each actuator 51, 61, and in this embodiment, the small diameter portion 54b, 64b of the piston 54, 64. The diameter of the large diameter portion 54a of the piston 54 is the same.
The diameter of the piston 64 is made larger than the diameter of the large diameter portion 64a of the piston 64, so that the brake hydraulic pressure applied to the front wheel cylinders 12, 12 is applied to the rear wheel cylinder 1.
The brake hydraulic pressure applied to brakes 5 and 15 is set to be higher, allowing for an appropriate distribution of front and rear braking force.

If such braking is so sudden that the front (rear) wheels are locked or are about to lock, a signal from the anti-skid control circuit 90 activates the solenoid 76.
(86) is energized. At this time, the solenoid coil 76 (86) moves the plunger 73 (83) to the spring 7.
2 (82) and pull the valve body 73 upward in the figure.
Drain port 7 that was closed at a (83a)
4 (84) and open the valve body 73b (83b).
to block port 75 (85). Kayo port 7
5 (85) is closed, drain port 74 (84)
actuator 51 (6) is opened.
The hydraulic pressure in the cylinder 52 (62) of 1) is extracted through the drain port 74 (84). This allows the piston 54 (64) to move into the small diameter cylinder 53.
(63) is moved to the left by the brake oil pressure, and the hydraulic oil sealed in the oil passage 14 (17) expands in volume, automatically locking the front wheel (rear wheel) due to a decrease in the front wheel (rear wheel) brake oil pressure. Can be canceled at

Through the above operations, the wheels are unlocked,
When the signal from the anti-skid control circuit 90 is removed and the solenoid 76 (86) is no longer energized, the plunger 73 is activated by the action of the spring 72 (82).
(83) moves downward in the figure, and its valve body 73a
(83a) is seated on the drain port 74 (84). Like this, drain port 74 (84)
is blocked, the actuator 51 (61)
The large diameter cylinder 52 (62) has a port 75.
Power oil pressure is again led from (85) through the oil groove 73c (83c), and normal braking operation is resumed.

Next, when the power oil pressure is lost due to a failure of the pump P, the pressure in the oil passages 34, 44 disappears, and the pistons 33, 43 of the closing parts 30, 40 and the pistons 54, 64 of the actuators 51, 61 are 45 and springs 56, 66 to the left to the illustrated position. Due to this leftward movement, the closing parts 30, 40
The valve bodies 33c and 43c are spaced apart from the valve seats 36 and 46, and communicate the oil passages 13 and 14 of the front brake system and the oil passages 16 and 17 of the rear brake system, respectively. The master cylinder oil pressure supplied to the oil passages 13 and 16 operates the electromagnetic switching valves 70 and 80.
Regardless of whether it is in operation or not, it is directly supplied to the front wheel cylinders 12, 12 and the rear wheel cylinders 15, 15 via the oil passages 14, 17, and braking operation is ensured in the same state as if there were no anti-skid device or booster device. Ru.

Thus, the hydraulic power brake of the present invention obtains a boost function by increasing the pressure by the hydraulic converter 20 and the actuators 51, 61 to obtain the brake oil pressure, and the actuators 51, 61 increase the pressure.
By making the large diameter/small diameter ratio of the pistons 54 and 64 of 1 different, a function to properly distribute the braking force between the front and rear wheels is obtained. Since the anti-skid function is obtained by supplying and discharging the liquid, the above three functions can be combined into one, which has the effect of making the entire device extremely compact. Moreover, since the pressure receiving area on the hydraulic pressure source side of the pistons of the hydraulic converter 20 and the actuators 51, 61 is made larger than the pressure receiving area on the master cylinder side, the hydraulic pressure on the hydraulic source side does not become so high.
In addition to reducing the size of the pump that forms part of the hydraulic power source and reducing the fuel consumption of the engine that drives the pump, it is also possible to improve the durability of the pipelines related to the hydraulic pressure of the hydraulic power source.

In addition, the closing parts 30 and 40 separate the oil passages 13 and 14 of the front brake system and the oil passages 16 and 17 of the rear brake system, and the brake hydraulic pressure of the oil passages 14 and 17 on the wheel cylinder side is controlled in an anti-skid manner. Since the control is performed by the parts 50 and 60, it is possible to ensure the braking function of the brake pedal even when a hydraulic power source such as a pump fails.

Furthermore, in the present invention, since the hydraulic pressure of the master cylinder during normal operation only operates the piston 23 of the hydraulic pressure converter 20, the stroke of the brake pedal 11 for operating the master cylinder can be made small, thereby providing a power brake device with no play. be able to. Moreover, since the amount of oil supplied to the master cylinder is small, the master cylinder can be made smaller.

Of course, if the switching valves 70 and 80 are removed, a hydraulic power brake without anti-skid control can be obtained.

[Brief explanation of the drawing]

The figure is a diagram showing an embodiment of the invention. 10... Tandem master cylinder, 11...
Master cylinder, 12...Front wheel cylinder, 13, 14...Front brake system, 1
5...Rear wheel cylinder, 16, 17...Rear brake system, 20...Hydraulic pressure converter, 23...Piston, 23c...Valve body, 24...Spring, 25...
...Drain port, P...Pump, 30,40...
...Closing part, 33, 43... Piston, 35, 45
... Spring, 36, 46 ... Valve seat, 50, 60 ...
Anti-skid control section, 51, 61... actuator, 54, 64... piston, 56, 66...
...Return spring, 70, 80...Solenoid switching valve, 72, 82...Spring, 73, 83...Plunger, 73a, 83a, 73b, 83b...Valve body, 74, 84...Drain port, 75, 85
...Power hydraulic inlet port, 76, 86...Solenoid coil, 90...Anti-skid control circuit.

Claims (1)

[Claims] 1. A hydraulic source, a brake system extending from the master cylinder to the wheel cylinder, and a closure that separates the brake system into an oil path on the master cylinder side and an oil path on the wheel cylinder side using the oil pressure of the oil pressure source. and a piston whose small diameter end communicates with the master cylinder side oil passage and whose large diameter end communicates with the hydraulic source oil pressure side oil passage, and the piston controls the hydraulic source oil pressure according to the oil pressure of the master cylinder side oil passage. and an actuator having a small diameter end that communicates with the wheel cylinder side oil passage and a large diameter end that includes a piston that receives the hydraulic pressure from the hydraulic source. Hydraulic power brake. 2. A switching valve is installed between the actuator and the hydraulic conversion section to stop the introduction of hydraulic pressure from the hydraulic source when the wheels lock or are about to lock, and to drain the hydraulic oil from the large diameter end of the actuator piston. A hydraulic power brake according to claim 1, comprising: 3. The master cylinder is a dandem master cylinder, the brake system is formed into a front brake system and a rear brake system, and the closing part and the actuator are respectively arranged for each brake. Hydraulic power brake as described in section. 4. The hydraulic power brake according to claim 3, wherein the ratio of the large diameter part and the small diameter part of the actuator piston is formed to be different between the front brake system and the rear brake system. 5. The hydraulic conversion section has a so-called variable throttle consisting of a drain port and a valve body, and the variable throttle is closed in accordance with the master cylinder oil pressure. Hydraulic power brake according to any of paragraphs.