JPH0379456A - Hydraulic controller - Google Patents

Abstract

PURPOSE:To strengthen braking force by heightening a cut point pressure through the energizing of a pressure control valve to keep communication of a rear wheel brake system by difference in liquid pressure between front and rear wheel brake systems after an anti skid device on the front wheel side operates. CONSTITUTION:When anti skid devices 6, 7 are respectively arranged on front and rear wheel brake system 3, 5 connecting a master cylinder 1 output side and respective front and rear wheel side brake devices 2, 4, a pressure control means 8 and a cut point pressure change means 9 are installed on a route connecting the anti skid device 7 on the rear wheel side to the brake device 4 on the rear wheel side. The pressure control means 8 is adapted to open and close a valve mechanism 26 according as a piston 16 shifts in response to difference in pressed area. The cut point pressure change means 9 to energize a piston 16 to keep communication of the wheel brake system 5 by difference in liquid pressure between the rear wheel brake system 5 brake and the front wheel side anti skid device 6 output.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hydraulic pressure control device provided in a brake of a vehicle.

(Prior Art) In general, in a vehicle such as an automobile, a heavy object such as an engine is placed at the front, so the load applied to the front wheels is greater than the load applied to the rear wheels. Therefore, the braking force on the front wheels greatly contributes to the braking of the vehicle, and the braking force distribution is set to be large for the front wheels and small for the rear wheels. This braking force distribution is normally set by the brake cylinder diameter and hydraulic pressure control valve of a brake device such as a disc brake or drum brake.

The hydraulic pressure control valve is designed to output hydraulic pressure at a rate smaller than the increase rate of the input hydraulic pressure when the braking hydraulic pressure input from the master cylinder reaches a certain pressure (cut point pressure). There is also a variable load type (LSPV) in which the cut point pressure increases as the vehicle load increases. This variable load type hydraulic pressure control valve increases the hydraulic pressure that starts to cause rear wheel lock as the load applied to the rear wheels increases, so by increasing the cut point pressure as the load increases, This allows the braking force of the wheels to be used more effectively. In addition,
This variable load type hydraulic pressure control valve detects the relative displacement between the rear wheels and the vehicle body, and controls are performed based on the detected relative displacement.

On the other hand, some vehicles are equipped with an anti-skid device that controls the brake fluid pressure of the brake system to prevent wheels from locking during sudden braking to ensure braking performance and steering stability. This anti-skid device
Usually, the front wheel side is provided for each brake system on the left and right, and the rear wheel side is provided either separately for the left and right brake systems or in common.

By using a combination of a hydraulic control valve and an anti-skid device in the flake, more efficient braking performance can be achieved. Furthermore, the braking force distribution is set so that the braking force is greater towards the front wheels.
Since the front wheels tend to lock up, the anti-skid device on the front wheels usually activates first.

(Problem to be solved by the invention) However, the hydraulic control valve starts controlling when the braking hydraulic pressure reaches a certain cut point pressure, and controls the supply of hydraulic pressure to the rear wheel brake system. As a result, when the vehicle is loaded, the braking force on the rear wheels will be reduced, and if the anti-skid device on the front wheels is activated, the hydraulic pressure of the rear wheels will decrease even if the brake pedal is pressed hard. There was a problem that the braking force was greatly lacking due to the low rate of rise.

In addition, a variable load type hydraulic pressure control valve can solve the above problem, but since the control is performed by detecting the relative displacement between the rear wheels and the vehicle body, the mounting position is restricted to a position where the relative displacement can be detected. There were some problems, such as the installation work being complicated.

The present invention was made in view of the above problems, and its purpose is to more efficiently secure braking force for the rear wheels without using a variable load type hydraulic pressure control valve. An object of the present invention is to provide a hydraulic pressure control device.

(Means for Solving the Problems) A hydraulic pressure control device of the present invention includes a front wheel brake, a system that connects a brake fluid pressure generation source and a front wheel brake device, and a system that connects a brake fluid pressure generation source and a rear wheel brake device. An anti-skid device is installed in each of the rear wheel brake systems that connect the rear wheel brake system, and a pressure receiving area on the downstream side or a pressure receiving area on the upstream side is installed in the line connecting the anti-skid device of the rear wheel brake system and the rear wheel side brake device. a hydraulic pressure control means comprising a larger piston and a valve mechanism that connects and shuts off the rear wheel brake system in accordance with the movement of the piston due to the difference in pressure receiving area as the brake fluid pressure increases, and the rear wheel brake system. and cut point pressure changing means for biasing the piston in a direction to maintain communication of the rear wheel brake system by a pressure difference between the brake fluid pressure of the brake system and the output side hydraulic pressure of the anti-skid device of the front wheel brake system. It is characterized by:

(Function) With the above configuration, before the anti-skid device operates, when the hydraulic pressure from the brake hydraulic pressure source increases and reaches a predetermined pressure (cut point pressure) by the hydraulic pressure control means,
The valve mechanism or the rear wheel brake system is repeatedly connected and disconnected in response to the movement of the piston due to the difference in pressure receiving area, suppressing the rate of increase in the brake fluid pressure supplied to the brake equipment, and distributing the braking force between the front and rear wheels. It functions as a normal hydraulic pressure control valve.

Then, when the anti-skid device of the front wheel brake system is activated to reduce the brake fluid pressure of the front wheel brake system, the cut point pressure changing means changes the pressure difference between the brake fluid pressure of the front wheel brake system and the rear wheel brake system to the rear wheel brake system. In order to urge the piston of the hydraulic pressure control means in a direction that maintains communication of the brake system, the cut point pressure is changed to a higher value and the braking force of the rear wheel brake device is maintained. Additionally, even if the cut point pressure is increased and the rear wheels tend to lock, the anti-skid device will activate to prevent the rear wheels from locking up.

In this way, even if the anti-skid device of the front wheel brake system is activated due to sudden braking, etc., the cut point pressure of the hydraulic pressure control means is changed to a high value so that the braking force on the rear wheel side can be used effectively. It becomes possible to secure the maximum braking force of the vehicle.

(Example) Next, a first example of the present invention will be described based on FIG. In this embodiment, the brake system is X-piped, and one of the two outputs of the mask cylinder, which is the source of brake fluid pressure, is piped to the right front wheel brake device and the left rear wheel brake device. , the other is piped to the left front wheel brake system and the right rear wheel brake system. Furthermore, since these two piping systems have the same configuration, only one system will be explained.

A front wheel brake system 3 that connects the output side of the mask cylinder 1 and the front wheel brake device 2 and a rear wheel brake system 5 that connects the output side of the mask cylinder 1 and the rear wheel brake device 4 are each provided with an anti-skid device. 6.7 is located. These anti-skid devices 6 and 7 are general devices in which a control section determines a state where locking is likely to occur based on the number of rotations of the wheels, etc., and a switching valve is controlled based on the determination to adjust the brake fluid pressure. It controls the braking force by reducing or increasing the pressure and prevents the wheels from locking.

A pressure control means 8 and a cut point pressure changing means 9 are provided in a line connecting the anti-skid device 7 of the rear wheel brake system 5 and the rear wheel side brake device 4.

To explain these means 8 and 9, inside the main body 10, from the right side in the figure, there are a small diameter cylinder part 11 and a large diameter cylinder part 12.
, a small-diameter cylinder part 13 and a medium-diameter cylinder part 14 are formed, and the cylinder 15 is provided with a piston 16 that is not slidable. piston 16
, two piston parts 17 and 18 are respectively formed in sliding contact with the large diameter cylinder part 12 and the medium diameter cylinder part 14, and the large diameter cylinder part 12 is connected to two chambers 19 and 20 by the piston part 17. Similarly, the medium diameter cylinder part 14 is divided into two chambers 21 and 22 by the piston part 18. In addition, each chamber 19, 20, 21.
22 is sealed by an O-ring 23...

A spring member 2 is provided in one chamber 19 of the large diameter cylinder portion 12.
4 are provided, and urge the piston 16 in one direction (to the left in the figure).

In addition, the piston ff1H sliding on the medium diameter cylinder portion 14
1, the pressure receiving area of the hydraulic pressure received from one chamber 21 on the upstream side is set to be smaller than the pressure receiving area of the hydraulic pressure received from the other chamber 22 on the downstream side. Further, the two chambers 21 and 22 of the medium diameter cylinder portion I4 communicate with each other through a communication passage 25 formed in the piston 16.
A valve mechanism 26 capable of communicating and blocking the communication path 25 is provided inside. This valve mechanism 26 includes a ball valve 28 that can be seated on a valve seat 27 formed in a communication passage 25, a spring member 29 that biases the ball valve 28 toward the valve seat 27, and a ball valve 28 that is fixed to the main body 10 and is connected to the valve seat 27. When the piston 16 is biased in one direction, the ball valve 28 is pushed by the rod 30 and the communicating passage 25 is in communication, and the piston 16 is biased in the other direction ( When the ball valve 28 is moved to the right (in the figure), the ball valve 28 is seated on the valve seat 27, and the communication path 25 is in a state of being blocked. Note that the piston 16 and the valve mechanism 26 constitute the hydraulic pressure control means 8.

The output side of the anti-skid device 7 provided in the rear wheel brake system 5 is connected to the large diameter cylinder portion 1 via the boat 31.
connected to one chamber 19 of 2.

The other chamber 19 is connected to one chamber 21 of the medium diameter cylinder portion 14 by a passage 32 formed in the main body 10 . The other chamber 22 of the medium diameter cylinder portion I4 is connected to a boat 33.
It is connected to the rear wheel brake device 4 via.

The output side of the anti-skid device 6 of the front wheel brake system 3 is connected to the other chamber 2 of the large diameter cylinder section 12 via the boat 34.
0, and further connected to the front wheel brake device 2 from the other chamber 20 via the boat 35. Note that the large diameter cylinder portion 12, the piston portion 17, and the chambers 19 and 20 constitute the cut point pressure changing means 9.

The operation related to the above configuration will be explained.

When hydraulic pressure is generated in the mask cylinder 1 during braking, in the front wheel brake system 3, the hydraulic pressure is supplied from the anti-skid device 6 to the front wheel brake device 2 through the other chamber 20 of the large diameter cylinder portion 12, In the rear wheel brake system 5, one chamber 191 passage 32 of the large diameter cylinder section 12, one chamber 21 of the medium diameter cylinder section 14. Hydraulic pressure is supplied to the rear wheel brake device 4 through the communication passage 25 and the other chamber 22 of the medium-diameter cylinder portion 14 to generate braking forces. In this state, the magnitude of the braking fluid pressure is the same until each anti-skid device 6, 7 operates, and the fluid pressure in one chamber 19 of the large diameter cylinder section 12 and the fluid pressure in the other chamber 20 are the same. The hydraulic pressure is the same.

When the brake fluid pressure rises and reaches a certain pressure (cut point pressure), the piston 16 moves in the other direction against the biasing force of the spring member 24 due to the difference in the pressure receiving area of the piston part 18 of the medium diameter cylinder part 14. The valve mechanism 26 or the communication path 25 is then moved. Also, if the communication path 25 is blocked, the mask cylinder 1
One chamber 21 of the medium diameter cylinder part 14 is opened by the hydraulic pressure from
The hydraulic pressure inside increases, and the piston portion 18 is pushed in one direction again, causing the valve mechanism 26 to communicate the communication passage 25. In this way, the piston 16 reciprocates in response to an increase in the brake fluid pressure on the master syringe 1 side, and the valve mechanism 26 causes the communication passage 25 to
By repeatedly communicating and disconnecting, the rate of increase in the hydraulic pressure supplied to the rear wheel brake device 4 is suppressed to a low level. This sets the braking force distribution between the front wheels and the rear wheels.

Next, when the anti-skid device 6 disposed in the front wheel brake system 3 is activated due to sudden braking, etc., and the brake fluid pressure supplied to the front wheels is reduced, the fluid in the other chamber 20 of the large diameter cylinder portion 12 is activated. The pressure is lower than the hydraulic pressure in one chamber 19, and the differential pressure generated in the piston part 17 or the piston 1
6 in one direction. Due to the biasing force, the movement of the piston 16 due to the difference in pressure receiving area caused by the increase in the brake fluid pressure of the rear wheel brake system 5 is suppressed by the differential pressure, and the cut point pressure is changed to a higher value. This maintains the braking force on the rear wheels. At this time, the hydraulic pressure supplied to the rear wheel brake system 4 increases, making it easy for the rear wheels to lock. is prevented.

Here, the cut point pressure is determined by appropriately setting the pressure receiving area of the hydraulic pressure received from one chamber 19 and the pressure receiving area of the hydraulic pressure received from the other chamber 20 in the piston part 17 that is in sliding contact with the large diameter cylinder part 12. It can be changed to an arbitrary value by adjusting the force that urges the piston 15 in one direction using the differential pressure.

In this way, by using the differential pressure generated between the front wheel brake system 3 and the rear wheel brake system 5 due to the operation of the anti-skid device 6 of the front wheel brake system 3 to change the cut point pressure to a higher level, the cut point pressure can be changed more effectively. It is possible to secure the braking force of the vehicle.

In addition, in this first embodiment, in the rear wheel brake system 5, the output side of the anti-skid device 7 and one chamber 19 of the large-diameter cylinder section 12 are connected, or the modification shown in FIG. As shown, the output side of the mask cylinder l is directly connected to one chamber 19 of the large diameter cylinder section 12, and the output side of the anti-skid device 7 is connected to one chamber 21 of the medium diameter cylinder section 14.
It may also be configured to be directly connected to. Note that even in this case, the same effect is obtained.

Next, a second embodiment of the present invention will be described based on FIG.

A front wheel brake system 36 connects the output of the mask cylinder 1, which is a brake fluid pressure generation source, and the front wheel brake device 2.
and the output of the master cylinder 1 and the rear wheel brake device 4
Similarly to the first embodiment, a general anti-skid device (18.39) is connected to the rear wheel brake system 37 which connects the rear wheel brake system 37 to the rear wheel brake system 37. In addition, the figure shows either the front wheel and the rear wheel as one unit, or the front wheel and the rear wheel are controlled separately (the front wheel has a
．． 39 is attached to the rear wheel side).

Continuing on, the hydraulic pressure control means 40 and the cut point pressure changing means 4 are arranged in a line connecting the anti-skid device 39 of the rear wheel brake system 37 and the rear wheel side flake device 4.
1 will be explained.

Inside the main body 42, a hydraulic pressure control means 40 and a force/point pressure changing means 41 are provided. First, the hydraulic pressure control means 4
0, there is a large diameter cylinder part 43 inside the main body 42.
A control cylinder 45 is formed which includes a small diameter cylinder part 44 and a piston part 4 that partitions the large diameter cylinder part 43 into two chambers 46 and 47.
A control piston 49 having a diameter of 8 is slidably provided. In addition, each chamber 46, 47 has an O-ring so,
sealed by so.

A spring member 5 is provided in one chamber 46 of the large diameter cylinder portion 43.
1 is provided to urge the control piston 49 in one direction (rightward in the figure).

Further, the piston portion 48 is set so that the pressure receiving area of the hydraulic pressure received from one chamber 46 on the upstream side is smaller than the pressure receiving area of the hydraulic pressure received from the other chamber 47 on the downstream side.

Further, the two chambers 46 and 47 communicate with each other through a communication passage 52 formed in the control piston 49, and a valve mechanism 53 capable of shutting off the communication passage 52 is provided in the communication passage 52. This valve mechanism 53 includes a ball valve 55 that can be seated on a valve seat 54 formed in a communication passage 52, a spring member 56 that biases the ball valve 55 toward the valve seat 54, and a spring member 56 that is fixed to the main body 42. , a rod 57 inserted into the communication passage 52, and when the control piston 49 is biased in one direction,
When the ball valve 55 is pushed by the rod 57 and the communication path 52 is brought into communication, and the control piston 49 moves in the other direction (to the left in the figure), the ball valve 55 is seated on the valve seat 54 and the communication path 52 is brought into communication. The passage 52 will be in a blocked state. The output side of the anti-skid device 39 of the rear wheel brake system 37 is connected to one chamber 46 of the large diameter cylinder section 43 via a cut point pressure changing means 41 which will be described in detail later.
The other chamber 47 is connected to the rear wheel side brake neck 4.

Next, the cut point pressure changing means 41 will be explained. Inside the main body 42, there is formed a differential pressure detection cylinder 61 consisting of a large diameter cylinder part 58 at the center and small diameter cylinder parts 59 and 60 on both sides. The pressure sensing cylinder 51 is slidably provided with a differential pressure sensing piston 65 having a piston portion 64 that partitions the large diameter cylinder portion 58 into two chambers 62, 6:1. Each chamber 62, 63 is sealed by an O-ring 66...

A spring member 67 is provided in one chamber 62 of the large diameter cylinder portion 58.
The piston 65 for differential pressure detection is provided in one direction (
(rightward in the figure). The other chamber 63 of the large diameter cylinder portion 58 is connected to the rear wheel brake system 3 via a boat 68.
7 to the output side of the anti-skid device 39, and is further connected to one chamber 4 of the control cylinder 45 via a passage 69.
6.

The differential pressure detection piston 65 includes a chamber 7 formed in the other chamber 63 of the large diameter cylinder chamber 58 and one small diameter cylinder 60.
A communication path 71 that communicates with 0 is formed. Communication path 7
1 includes a communication passage 7 having the same structure as the valve mechanism 53.
1 is also provided. The configuration of this valve mechanism 72 is the same as that of the valve mechanism 53, so a description thereof will be omitted. When the differential pressure detection piston 65 is biased in one direction, the valve m mechanism 72 is connected to the communication path 71.
When the differential pressure detection piston 65 moves in the other direction (to the left in the figure), the communication path 71 is brought into communication.

On the small diameter cylinder portion 44 side of the control cylinder 45,
An adjustment cylinder 73 is formed, and an adjustment piston 76 that partitions the adjustment cylinder 73 into two chambers 74 and 75 is slidably provided in the adjustment cylinder 73. The control piston 4 is located in one chamber 74.
9 in one direction, and the other chamber 75 is connected to the chamber 70 of the small diameter cylinder portion 60 of the differential pressure detection cylinder 1 and the passage formed in the main body 42. They are connected via 78. Also, aisle 7
8 branches in the middle and is connected to the output side of the mask cylinder 1 via a passage 79 and a conduit 80 formed in the main body 42. Note that the passage 78 is provided with a reverse valve 81 that allows only the flow of oil from the chamber 70 to the other chamber 75 of the adjusting cylinder tough 3, and the first passage 79 is provided with a reverse valve 81 that allows the oil to flow only from the chamber 70 to the other chamber 75 of the adjusting cylinder 73 from the chamber 75 of the mask cylinder 1
A check valve 82 is provided to allow the oil fluid to flow to the output side.

The output side of the anti-skid device 38 of the front wheel brake system 36 is connected to one chamber 62 of the differential pressure detection cylinder 1 via a boat 83, and the boat 83 branches off in the middle to connect to the rear wheel brake device 2. and is connected via a passage 84.

The operation related to the above configuration will be explained.

When hydraulic pressure is generated in the mask cylinder 1 during braking, in the front wheel brake system 36, the hydraulic pressure is supplied from the anti-skid device 38 through the boat 83 to the front wheel side flake system I12, and then to the rear wheel brake system 37. , from the anti-skid device 39 to the large-diameter cylindrical portion 5 of the differential pressure detection cylinder 1.
Hydraulic pressure is supplied to the rear wheel side flaking device 4 through the other chamber 63 of the control cylinder 45, the passage 69, the one chamber 46 of the large diameter cylinder portion 43 of the control cylinder 45, the communication passage 52, and the other chamber 47. Braking force is generated respectively. In this state, until each anti-skid device 38, 39 operates, the braking fluid pressure is the same as the fluid pressure in one chamber 62 of the large diameter cylindrical portion 58 of the differential pressure detection cylinder 1. The hydraulic pressure in the other chamber 63 is the same.

When the braking fluid pressure increases and reaches a certain fluid pressure (cut point pressure), the control piston 49 moves in the other direction against the biasing force of the spring member 51 due to the difference in the pressure receiving area of the piston portion 48, and the valve The mechanism 53 blocks the communication path 52. Furthermore, when the communication passage 52 is cut off, the hydraulic pressure in one chamber 46 of the large diameter cylinder section 43 increases due to the hydraulic pressure from the mask cylinder 1, which pushes the piston section 48 in one direction again and causes the valve mechanism 53 to communicate. The passage 52 is communicated. In this way, the control piston 49 reciprocates in response to an increase in the brake fluid pressure on the mask cylinder l side, and the valve mechanism 53 repeatedly communicates and blocks the communication path 52, thereby causing the rear wheel brake device 4
The rate of increase in the fluid pressure supplied to is kept low. This results in
The braking force distribution between the front and rear wheels is set.

Next, when the anti-skid device 38 disposed in the front wheel brake system 36 is activated due to sudden braking and the brake fluid pressure supplied to the front wheels is reduced, the large diameter cylinder portion 58 of the differential pressure detection cylinder 61 is activated. The hydraulic pressure in one chamber 62 becomes lower than the hydraulic pressure in the other chamber 63, and the spring member 87
The differential pressure detecting piston 65 moves in the other direction against the urging force of the valve mechanism 72 to cause the communication passage 71 to communicate with the valve mechanism 72 . Therefore, the brake fluid pressure on the rear wheel side is introduced into the other chamber 75 of the adjustment cylinder 73, and moves the adjustment piston 76 in one direction. As a result, the spring member 77 presses and biases the control piston 49 in one direction, and the control piston 49 moves due to the difference in pressure receiving area due to the rise in braking fluid pressure of the rear wheel brake system 37. The pressure at the cut point is increased by the biasing force of the spring member 77. At this time, either the hydraulic pressure supplied to the rear wheel brake system 4 increases and the rear wheels are likely to lock, or the anti-skid device 39 of the rear wheel brake system 37 operates, causing the lock to occur. Since this is prevented, braking force can be effectively maintained.

Here, the cut point pressure is determined by appropriately setting the elastic force of the spring member 77 provided in one chamber 74 of the adjustment cylinder 73 to adjust the force that urges the control piston 49 in one direction. You can change it to any value by doing this.

In addition, in this second embodiment, the hydraulic pressure introduced into the other chamber 75 of the adjustment cylinder 73 is applied to the anti-skid device 3.
Regardless of the operation of 8.39, this is maintained until the mask cylinder 1 stops generating brake fluid pressure.

(Effects of the Invention) As explained in detail above, the present invention provides communication between the rear wheel brake system by the differential pressure between the front wheel brake system and the rear wheel brake system after the front wheel side anti-skid device is activated. By biasing the piston in the direction to maintain the cut point pressure and increasing the pressure at the cut point, the braking force on the rear wheel side can be used effectively, thereby improving the braking force of the vehicle.

In addition, since there is no need to use the conventional load variable hydraulic pressure control valve, the degree of freedom in installation and other settings is increased.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a first embodiment of the hydraulic pressure control device of the present invention, FIG. 2 is a schematic diagram showing a modification of the first embodiment shown in FIG. 1, and FIG. FIG. 2 is a schematic diagram showing a second embodiment of the hydraulic pressure control device of the present invention. 1... Master cylinder (flake hydraulic pressure generation source) 2... Front wheel side flake device 3... Front wheel flake system 4... Rear wheel side flake device 5... Rear wheel flake system 6.7... Anti-skid device 8...hydraulic pressure control means 9...cut point pressure changing means 12...large diameter cylinder section 15...piston 17...piston sections 1, 9, 20...chamber 26.・・Valve mechanism

Claims (1)

[Claims] (1) An anti-skid device is provided in each of the front wheel brake system that connects the brake fluid pressure generation source and the front wheel brake device and the rear wheel brake system that connects the brake fluid pressure generation source and the rear wheel brake device. , A piston with a pressure receiving area on the downstream side that is larger than the pressure receiving area on the upstream side and a pressure receiving area as the brake fluid pressure increases are installed in the system that connects the anti-skid device of the rear wheel brake system and the rear wheel side brake device. The rear wheel brake system is connected and connected according to the movement of the piston due to the difference in area.
a hydraulic pressure control means consisting of a valve mechanism that shuts off; and a direction for maintaining communication between the rear wheel brake system by a differential pressure between the brake hydraulic pressure of the rear wheel brake system and the hydraulic pressure on the output side of the anti-skid device of the front wheel brake system. A hydraulic pressure control device comprising: cut point pressure changing means for biasing the piston;