JPH1081223A - Brake control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smooth a suction stroke in each reciprocating pump by shifting a plunger driving phase between both first and second reciprocating pumps to some extent, and making a plunger in the second reciprocating pump into a discharge stroke at a time when a plunger in the first reciprocating pump is made into a suction stroke. SOLUTION: A booster pump 24 as a first reciprocating pump is fitted in the one end side of a cylinder 34 free of sliding motion and a plunger 36 coming into contact with an eccentric cam 35 for this booster pump is installed in a camshaft at its end face. In addition, an auxiliary pump 25 as a second reciprocating pump is fitted in the one end side of a cylinder 56 free of sliding motion and a plunger 58 coming into contact with an eccentric cam for this booster pump is installed in a camshaft 56 at its one end face. Then, each driving phase of two plungers 36 and 58 of these pumps 24 and 25 is made so as to be shifted to some extent so as to make the plunger 58 of the auxiliary pump 25 come to the discharge stroke at a time when the plunger 36 of the booster pump 24 is made into the suction stroke. With this constitution, each suction stroke of these pumps 24 and 25 is made smoothable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for suppressing slip of a drive wheel which occurs when an excessive drive torque is applied to a drive wheel of a vehicle, and for preventing locking of the wheel which occurs during braking of the vehicle. To a brake control device.

[0002]

2. Description of the Related Art When excessive driving torque is applied to driving wheels due to acceleration of a vehicle or a sudden change in road surface conditions,
In some cases, a sudden slip occurs between the road surface and the drive wheels, and the driving force from the engine cannot be effectively transmitted to the road surface. Further, if a sharp turning operation is performed during turning of the vehicle, there is a possibility that stability of the vehicle may be impaired and spin or the like may occur. Furthermore, when the vehicle is suddenly braked or when the vehicle is braked on an icy road, the braking force on the wheels becomes excessive, and the wheels are likely to lock. Control becomes extremely difficult.

[0003] Such a slip rotation of drive wheels (hereinafter referred to as "slip rotation").
This is referred to as acceleration slip), to prevent a spin occurring in a turning vehicle due to rapid steering (hereinafter referred to as a turning spin), or to lock a wheel during braking. For the purpose of preventing (hereinafter, referred to as a braking slip), a brake wheel cylinder of each wheel (hereinafter, abbreviated as a wheel cylinder).
For example, Japanese Patent Publication No. 7-80445 proposes a brake control device that controls the brake fluid pressure for the vehicle.

This brake control device is operated by a non-energized closing type on / off valve in the middle of a first flow path connected to a master cylinder and a suction valve of a main pump, and a drive motor separate from the main pump. The auxiliary pump is arranged in order from the upstream side, and the other end of the brake fluid return passage having one end connected to the wheel cylinder is connected to the middle of the first flow path between the suction valve of the main pump and the auxiliary pump. In the middle of the brake fluid return passage, a non-energized closed type discharge on-off valve and a reservoir are arranged in order from the wheel cylinder side, and the intervening brake fluid return passage is connected, and the main pump discharge valve, wheel cylinder and A non-energized supply open / close valve for supply is incorporated in the middle of the second flow path connected to the vehicle so that the wheel cylinder can be pressurized regardless of whether the brake pedal is depressed or not. .

[0005]

[Problems to be solved by the invention] Japanese Patent Publication No. 7-80445
In the conventional brake control device disclosed in Japanese Patent Application Laid-Open Publication No. H11-107, the drive motors for the main pump and the auxiliary pump are required independently of each other, so that the power consumption increases and the mountability of the vehicle with the increase of the hydraulic unit increases. And the production cost rises.

In view of the above, it has been considered to employ a reciprocating pump as the main pump and the auxiliary pump described above and operate them with a single drive motor. In this case, if the driving phases of the plungers 103 and 104 of the main pump 101 and the auxiliary pump 102 are in the same phase as shown in FIGS. During the suction stroke, the brake fluid is simultaneously drawn into the pump chambers 107 and 108 formed in the casings 105 and 106 of the main pump 101 and the auxiliary pump 102, so that the discharge valve 109 of the auxiliary pump 102, It is necessary to set the passage cross-sectional area of the brake fluid flow passage 110 upstream of the suction valve 101 to be sufficiently large, and to take care that no throttle or the like is interposed in the middle thereof. As a result, the hydraulic unit becomes large. There was a fear.

In the brake fluid discharge stroke shown in FIG. 5, the brake fluid is simultaneously discharged from the main pump 101 and the auxiliary pump 102.
Brake fluid flow path 11 downstream of the second discharge valve 109
1, the load on the pump drive shaft 114 provided with the eccentric cams 112 and 113 becomes extremely large, and it is necessary to use a drive motor (not shown) having a large capacity, which leads to an increase in component costs. In addition, if the insides of the pump chambers 107 and 108 are in a negative pressure state during the above-described suction stroke, there is a possibility that a predetermined boosting characteristic cannot be obtained during the discharge stroke of the main pump 101 and the auxiliary pump 102.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to drive a pair of reciprocating pumps with a single driving motor so that the suction stroke of these reciprocating pumps can be performed smoothly and the driving motor for driving them has a small capacity. It is an object of the present invention to provide a brake control device that can be used.

[0009]

A brake control device according to the present invention comprises a first opening / closing valve provided in a main brake fluid passage connecting a brake master cylinder and a brake wheel cylinder, and a first opening / closing valve. One end communicates with the supply on-off valve provided in the main brake fluid passage between the brake wheel cylinder and the main brake fluid passage between the supply on-off valve and the first on-off valve. A first reciprocating pump having the other end provided in an auxiliary brake fluid passage communicating with the brake master cylinder and discharging brake fluid toward the main brake fluid passage;
Is provided in the sub-brake fluid passage between the reciprocating pump and the brake master cylinder to discharge the brake fluid toward the first reciprocating pump and to drive the plunger of the first reciprocating pump with respect to the driving phase. A second reciprocating pump having a plunger whose driving phase is shifted, a second on-off valve provided in the auxiliary brake fluid passage between the second reciprocating pump and the brake master cylinder,
A discharge opening / closing valve provided in a brake fluid return passage having one end communicating with the auxiliary brake fluid passage between the reciprocating pump and the second reciprocating pump and having the other end communicating with the brake wheel cylinder; Discharge on-off valve and the first
A reservoir provided in the brake fluid return passage between the suction valve and the suction valve of the reciprocating pump, a pump driving motor for driving the first reciprocating pump and the second reciprocating pump, and an operation of the pump driving motor And control means for controlling the opening and closing of the first on-off valve, the supply on-off valve, the discharge on-off valve, and the second on-off valve in accordance with the operating state of the vehicle. Things.

Therefore, when a normal braking operation is performed by the driver, the brake fluid in the master cylinder is supplied from the main brake fluid passage to the wheel cylinder, and a braking force substantially corresponding to the braking operation is generated. At this time, the supply opening / closing valve and the first opening / closing valve are in the open state, and the discharge opening / closing valve and the second opening / closing valve are in the closed state by the control device.

When an excessive driving force is applied to the driving wheels and the driving wheels start to spin, the first opening / closing valve is switched to the closed state and the second opening / closing is performed based on a command from the control means. The valve is switched to the open state, and the pump drive motor operates to drive the first reciprocating pump and the second reciprocating pump, so that the brake fluid on the brake master cylinder side flows from the sub brake fluid passage to the main brake fluid passage. The driving wheel is supplied to the wheel cylinder to suppress idling of the driving wheel.

When it is no longer necessary to increase the pressure of the brake fluid in the wheel cylinders during braking or accelerating the vehicle, the supply on-off valve is switched to a closed state based on a command from the control device. Instead, the brake fluid pressure in the wheel cylinder is maintained. Further, when it becomes necessary to reduce the brake fluid pressure in the wheel cylinder, the discharge on-off valve is opened based on a command from the control device, and the brake fluid in the wheel cylinder is discharged to the brake fluid return passage side. As a result, the brake fluid pressure in the wheel cylinder is reduced.

The driving phase of the plunger of the first reciprocating pump and the plunger of the second reciprocating pump are shifted. For example, when the first reciprocating pump is in the suction stroke, the second reciprocating pump is in the second reciprocating pump. When the first reciprocating pump is in the discharge stroke, the second reciprocating pump is in the suction stroke.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a brake control device according to the present invention, a driving phase of a plunger of a first reciprocating pump,
The driving phase of the plunger of the first reciprocating pump may be set substantially opposite to that of the first reciprocating pump, and the second reciprocating pump supplies the brake fluid into the pump chamber during the suction stroke of the plunger of the first reciprocating pump. The driving phase of the second reciprocating pump may be shifted from the driving phase of the plunger of the first reciprocating pump.

Further, the second reciprocating pump may discharge the brake fluid toward the pump chamber of the first reciprocating pump, and the brake fluid return passage may be connected to a suction valve of the first reciprocating pump. One end may be communicated with the pump chamber via the pump. Further, the driving state of the vehicle may be a slip amount of a driving wheel.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a brake control device according to the present invention is applied to a rear wheel drive vehicle will be described in detail with reference to FIGS.

As shown in FIG. 1 showing a brake hydraulic circuit according to the present embodiment and FIG. 2 showing a sectional structure of a main part, a master cylinder 12 to which a brake pedal 11 depressed by a driver is connected is provided with two systems. One ends of the main brake fluid passages 13a and 13b (hereinafter sometimes simply referred to as 13) are in communication with each other, and the other ends of the main brake fluid passages 13 are bifurcated into one branch. The main brake fluid passage 13a is connected to the right front wheel and left rear wheel cylinders _14FR , _14RL , and the other main brake fluid passage 13b is connected to the left front wheel and right rear wheel cylinders _14FL , _14RR . doing.

Also, in the middle of each main brake fluid passage 13, electromagnetic switching valves 15a and 15b for braking slip as first opening / closing valves of the present invention which are opened when the power is not supplied (hereinafter, these are simply referred to as 15). Do) and wheel cylinder 1
4 _FR, 14 _RL, 14 _FL, 14 _RR first check valve 16a for preventing the backflow of the brake fluid (hereinafter, these sometimes simply described as 14 collectively) side to the master cylinder 12 side, 16b (hereinafter simply referred to as 16) are provided in parallel. Furthermore, in the middle of the main brake fluid passage 13 between the brake slip electromagnetic switching valve 15 and the first check valve 16 and each wheel cylinder 14, a supply electromagnetic switching valve 17 that is opened when no power is supplied.
a and 17b (hereinafter simply referred to as 17) are interposed in correspondence with the wheel cylinders 14, respectively.

The above-mentioned electromagnetic switching valve 15 for braking slip
When an acceleration slip of a drive wheel occurs or the vehicle is likely to generate a turning spin, a control device 18 described later is used.
Except for closing based on a command from (see FIG. 3), the normally open state is maintained. In addition, the supply electromagnetic switching valve 17 is connected to the control device 18 during braking slip.
In this case, the brake fluid in the wheel cylinder 14 is kept open as long as the fluid pressure of the brake fluid in the wheel cylinder 14 is maintained as it is, or the brake fluid is closed when the pressure is reduced.

Therefore, the driver operates the brake pedal 11
When the brake pedal is depressed, the brake fluid pressure generated in the master cylinder 12 is transmitted from the braking slip electromagnetic switching valve 15 and the main brake fluid passage 13 to the respective wheel cylinders 14 via the supply electromagnetic switching valve 17, and is transmitted to the brake fluid pressure. A braking force based on this is generated.

On the other hand, the reservoir 19 communicating with the master cylinder 12 has two sub-brake fluid passages 20a, 20a.
b (hereinafter simply referred to as 20) communicate with each other, and the other ends of these auxiliary brake fluid passages 20
Electromagnetic switching valve 15 for braking slip and first check valve 1
6 and the supply electromagnetic switching valve 17, and communicates with the main brake fluid passage 13 in the middle. This auxiliary brake fluid passage 20
In the order of from the main brake fluid passage 13, orifices 21 a and 21 b (hereinafter simply referred to as 21) and a damper tank 22 a, which suppresses pulsation of brake fluid flowing in the sub brake fluid passage 20. 22b (hereinafter simply referred to as 22) and two systems of pressurizing pumps 24a, 2 operated by one pump drive motor 23 to supply the brake fluid to the main brake fluid passage 13 side.
4b (hereinafter, simply referred to as 24) and auxiliary pumps 25a, 25b (hereinafter, referred to as 24) which are driven integrally with the pressurizing pump 24 to supply the brake fluid in the reservoir 19 to the pressurizing pump 24 side. , These are simply referred to as 25), and acceleration slip electromagnetic switching valves 26a, 26b (hereinafter, these are simply referred to as 26) that are closed when not energized are interposed in series.

The above-described electromagnetic switching valve 26 for acceleration slip
In the case where an acceleration slip of the drive wheels occurs or the vehicle is likely to generate a turning spin, the normally closed state is maintained except for opening based on a command from the control device 18. ing.

One end is connected to the main brake fluid passage 13 between the master cylinder 12 and the electromagnetic switching valve 15 for braking slip, and the other end is connected to the sub brake fluid passage 20 between the orifice 21 and the pressurizing pump 24. Are connected to brake fluid relief passages 27a and 27b (hereinafter simply referred to as 27), and relief valves 28a and 27b for maintaining the brake fluid pressure discharged from the pressurizing pump 24 at a predetermined level or less.
28b (hereinafter, these are simply referred to as 28) are provided.

The other ends of the brake fluid return passages 29a and 29b (hereinafter simply referred to as 29), one end of which communicates with the pressurizing pump 24, are branched into two forks, respectively, and are divided into the wheel cylinder 14 and the supply electromagnetic. The main brake fluid passage 13 communicates with the switching valve 17 in the middle thereof.
Discharge electromagnetic switching valves 30 a and 30 b (hereinafter simply referred to as 30) which are closed when no power is supplied are interposed at the other ends of the auxiliary brake fluid passages 20 in correspondence with the respective wheel cylinders 14. ing.

The electromagnetic switching valve 30 for discharging is normally closed except that it is opened when the brake slip is performed to reduce the pressure of the brake fluid in the wheel cylinder 14 based on a command from the control device 18. Is maintained.

In the brake fluid return passage 29,
Reservoirs 31a and 31b for temporarily storing brake fluid
(Hereinafter, these may be simply described as 31).

The above-mentioned pressurizing pump 24 and auxiliary pump 25
1 will be described in more detail with reference to FIG. 1. These are arranged 180 degrees apart from each other with the cam shaft 32 of the pump drive motor 23 interposed therebetween, and are housed in one casing 33. Has become.

The pressurizing pump 24 as the first reciprocating pump of the present invention has a cup-shaped cylinder 34 whose one end is held by a casing 33, and is slidably fitted to one end of the cylinder 34. Plunger 36 having one end surface in contact with eccentric cam 35 for a pressure pump provided on cam shaft 33
A compression spring 37 interposed between the plunger 36 and the cylinder 34 to urge the plunger 36 toward the eccentric cam 35 for the pressure pump; and a casing 33 for holding the other end of the cylinder 34. And a lock nut 39 which is screwed into the casing 33 to fix the cylinder 34 and the cylinder retainer 38 in the casing 33.

At the center of the other end of the plunger 36, a discharge-side liquid chamber 40 surrounded by the other end surface of the cylinder 34 and the cylinder holder 38, and the other end of the cylinder 34 and the plunger 3
A communication hole 42 is formed which opens to the pump chamber 41 surrounded by the other end surface of the pump chamber 6. An annular gap 4 surrounded by a casing 33, a cylinder 34, and a cylinder retainer 38.
3 communicates with the auxiliary brake fluid passage 20, and the annular gap 43 and the discharge side fluid chamber 40
8 are in communication with each other via a communication groove 44 formed therein.

On the other hand, at the center of the plunger 36,
A blind hole 45 that opens into the pump chamber 41 is formed. A plurality of communication holes 47 communicating with an annular groove 46 formed on the outer periphery of the plunger 36 are radially formed at the bottom of the blind hole 45. An annular groove 4 communicating with the brake fluid return passage 29 is provided at one end of the cylinder 34.
8 is formed on the outer periphery of the annular groove 4.
8 and the inner peripheral side is the annular groove 4 of the plunger 36.
A plurality of communication holes 49 communicating with 6 are formed radially on one end side of the cylinder 34. In this case, the camshaft 33
The communication hole 49 of the cylinder 34 is always in communication with the annular groove 46 of the plunger 36 even when the plunger 36 reciprocates with respect to the cylinder 34 by the rotation of the eccentric cam 35 for the pressure pump integrated with the cylinder. The dimensions and shape of the communication hole 49 or the annular groove 46 are appropriately set.

The discharge side liquid chamber 40 is provided with a discharge valve ball 50 as a discharge valve capable of opening and closing the communication hole 42, and a compression spring 5 for urging the discharge valve ball 50 to the communication hole 42.
1 are stored. Similarly, in the pump chamber 41, a suction valve plate 52 as a suction valve capable of opening and closing the blind hole 45 of the plunger 36, the suction valve plate 52 is slidably held, and a communication hole 53 is formed around the suction valve plate 52. And a compression spring 55 interposed between the valve plate holder 54 and the suction valve plate 52 for urging the suction valve plate 52 to the stop hole 45. Have been. The valve plate holder 54 is always pressed against the other end surface of the plunger 36 by the compression spring 37 described above.

On the other hand, the auxiliary pump 25 as the second reciprocating pump of the present invention has basically the same structure as the above-described pressurizing pump 24, and has a cup-shaped cylinder whose one end is held by the casing 33. A plunger 58 slidably fitted to one end of the cylinder 56 and having one end abutting against an eccentric cam 57 for a pressure pump provided on a cam shaft 56; The plunger 58 is interposed between the eccentric cam 5 for the pressure pump.
7, a cup-shaped cylinder retainer 60 fitted to the casing 56 to hold the other end of the cylinder 56, a cylinder 56 and a cylinder retainer 60 screwed into the casing 56. And a lock nut 61 for fixing the inside of the casing 56.

At the center of the other end of the plunger 58, a discharge-side liquid chamber 62 surrounded by the other end surface of the cylinder 56 and the cylinder holder 60, and the other end of the cylinder 56 and the plunger 5
A communication hole 64 that opens to the pump chamber 63 surrounded by the other end surface of the pump 8 is formed.

An annular gap 65 surrounded by the casing 56, the cylinder 56, and the cylinder retainer 60 is provided in an annular groove 66 formed in the outer periphery of the other end of the cylinder 34 of the pressurizing pump 24 with a sub brake fluid passage. 20, the annular groove 66 and the pump chamber 41 of the pressure pump 24.
Is in a communicating state via a communicating hole 67 formed in the cylinder 34 of the pressurizing pump 24. Furthermore, the annular gap 65 and the liquid chamber 62 on the discharge side are
The communication state is established through the communication groove 68 formed at zero.

On the other hand, at the center of the plunger 58,
A blind hole 69 that opens into the pump chamber 63 is formed. A plurality of communication holes 71 communicating with an annular groove 70 formed on the outer periphery of the plunger 58 are radially formed at the bottom of the blind hole 69. At one end of the cylinder 56, an annular groove 72 communicating with the auxiliary brake fluid passage 20 on the side of the electromagnetic switching valve 26 for accelerating slip is formed on the outer periphery, and the outer peripheral side communicates with the annular groove 72. A plurality of communication holes 73 whose inner peripheral side communicates with the annular groove 70 of the plunger 58 are formed radially on one end side of the cylinder 56. In this case, even if the plunger 58 reciprocates with respect to the cylinder 56 by the rotation of the eccentric cam 57 for the pressure pump integrated with the cam shaft 56, the communication hole 73 of the cylinder 56 is always in the annular groove 72 of the plunger 58. The dimensions and shape of the communication hole 73 or the annular groove 72 are appropriately set so that the communication state is established.

The discharge side liquid chamber 62 has a discharge valve ball 74 as a discharge valve capable of opening and closing a communication hole 64, and a compression spring 7 for urging the discharge valve ball 74 to the communication hole 64.
5 are stored. Similarly, in the pump chamber 63, a suction valve plate 76 as a suction valve capable of opening and closing a blind hole 69 of the plunger 58, the suction valve plate 76 is slidably held, and a communication hole 77 is formed around the suction valve plate 76. And a compression spring 79 interposed between the valve plate holder 78 and the suction valve plate 76 for urging the suction valve plate 76 to the stop hole 69. Have been. The valve plate holder 78 is constantly pressed against the other end surface of the plunger 58 by the compression spring 59 described above.

Accordingly, when the plunger 36 of the pressure pump 24 starts to move toward the cylinder holder 38 due to the rotation of the pressure pump eccentric cam 35 integrated with the cam shaft 33, the volume of the pump chamber 41 decreases. Due to the pressure difference between the pump chamber 41 and the discharge-side liquid chamber 40, the valve ball 50 is displaced away from the cylinder 56, and the brake fluid in the pump chamber 41 is discharged from the auxiliary brake fluid passage 20 through the discharge-side liquid chamber 40. It is discharged to the main brake fluid passage 13 side. At this time, the plunger 58 of the auxiliary pump 25 starts to move toward the camshaft 32, the volume of the pump chamber 63 increases, and the brake fluid in the reservoir 19 flows from the auxiliary brake fluid passage 20 via the acceleration switching electromagnetic switching valve 26. Thus, the brake fluid is sucked into the pump chamber 63.

Conversely, when the plunger 36 of the pressurizing pump 24 starts to move toward the camshaft 32, a pressure difference is generated between the stop hole 45 and the pump chamber 41 as the volume of the pump chamber 41 increases, The suction valve plate 5 is separated from the plunger 59.
2 is displaced in the valve plate holder 54, so that the auxiliary pump 25
And the brake fluid from the brake fluid return passage 29 side is sucked into the pump chamber 41. At this time, the plunger 58 of the auxiliary pump 25 starts to move to the cylinder holder 60 side,
Since the volume of the pump chamber 63 is reduced, the pump chamber 64
The valve ball 74 is displaced away from the cylinder 56 due to the pressure difference between the pressure and the discharge side liquid chamber 62, and the brake fluid in the pump chamber 63 is pumped to the pressure pump 24 side.

In this case, the plunger 3 of the pressure pump 24
6 and the driving phase of the plunger 58 of the auxiliary pump 25 are opposite to each other, so that the eccentric direction of the eccentric cam 35 for the pressure pump and the eccentric direction of the eccentric cam 57 for the pressure pump with respect to the camshaft 32. Are set to a state of being shifted by approximately 180 degrees. When the pressurizing pump 24 is in the suction stroke, the auxiliary pump 25 is in the discharge stroke. Conversely, when the pressurizing pump 24 is in the discharge stroke, the auxiliary pump 25 is This is the suction stroke.

In particular, the driving phase of the plunger 36 of the pressurizing pump 24 is adjusted so that the brake fluid is supplied from the auxiliary pump 25 into the pump chamber 41 during the suction stroke of the plunger 36 of the pressurizing pump 24. It is desirable to shift the drive phase of the plunger 58 of the valve 25, the delay time due to the pipe resistance in the brake fluid flow path from the auxiliary pump 25 to the pressurizing pump 24, the valve opening delay time of the valve ball 74, and the camshaft 32. The eccentric direction of the eccentric cam for pressurizing pump 35 with respect to the cam shaft 32 and the eccentric direction of the eccentric cam 57 for pressurizing pump may be appropriately set in consideration of the rotational speed of the cam shaft 32.

Therefore, the load on the camshaft 32 is reduced by half compared to the case shown in FIGS. 4 and 5, and the pump drive motor 23 having a small capacity can be used. Further, when the auxiliary pump 25 is in the suction stroke, the inside of the pump chamber 63 of the auxiliary pump 25 may have a negative pressure, but in the discharge stroke, the pressurizing pump 24 is in the suction stroke and the auxiliary pump 25
Pump fluid is supplied from the
There is no problem that the step-up response of No. 4 is impaired.

When the brake fluid from the auxiliary pump 25 is supplied to the pump chamber 41 of the pressurizing pump 24, the suction valve plate 52 is stopped by the spring force of the compression spring 55.
5 is closed, there is no possibility that the brake fluid flows from the pressurizing pump 24 to the brake fluid return passage 29 side.

In this way, the brake fluid is intermittently discharged from the auxiliary pump 25 and the pressure pump 24 to the main brake fluid passage 13 via the auxiliary brake fluid passage 20 with the reciprocating movement of the plungers 36, 58. You.

As shown in FIG. 3 showing a control block of this embodiment, drive wheel speed sensors 80 _RL and 80 _RR for detecting the rotation speed of the rear wheels to which power from an engine (not shown) is transmitted.
(Hereinafter, simply referred to as 80), and driven wheel speed sensors 81 _FL and 81 _FR which detect the rotational speed of the front wheels that rotate with the relative movement between the vehicle and the road surface (hereinafter, simply referred to as 81). Based on detection signals from a steering angle sensor 82 for detecting the steering angle of the front wheels and a yaw sensor 83 for grasping the vehicle's rolling state, that is, yaw, a braking slip occurs on each wheel. It is determined whether or not an acceleration slip has occurred in the rear wheels, or whether or not the vehicle is in a state where the vehicle is likely to spin. Based on the determination result, the electromagnetic switching valve 15 for braking slip and the electromagnetic switching for acceleration slip are determined. The energization of the valve 26 is switched on / off, and the energization of the supply electromagnetic switching valve 17 and the discharge electromagnetic switching valve 30 is performed according to the degree of slip of each wheel. Of the pressurizing pump 24 and the auxiliary pump 25 by turning on / off the power supply to the pump driving motor 23,
The desired characteristics are obtained.

The method of determining the above-described braking slip, acceleration slip, and turning spin, and the specific control method therefor have been known in the past and have no direct relation to the present invention. A specific mode of operation after the above-described determination will be described.

For example, when the driver operates the brake pedal 11
When the brake pedal is depressed, the brake fluid in the master cylinder 12 is transmitted to the main brake fluid passage 13 via the electromagnetic switching valve 15 for braking slip, and is supplied to the wheel cylinder 14 via the electromagnetic switching valve 17 for supply. Power is generated. Further, the brake fluid pressure in the main brake fluid passage 13 is gradually accumulated in the damper tank 22 via the orifice 21.

Here, the controller 18 controls the driving wheel speed sensor 8
When it is determined that a braking slip has occurred in any of the wheels and the brake fluid pressure in the wheel cylinder 14 needs to be reduced based on the detection signals from the zero and the driven wheel speed sensor 81, the control device 18 Outputs pressure reduction signal. Specifically, the supply electromagnetic switching valve 17 and the discharge electromagnetic switching valve 30 are energized to cut off the brake fluid pressure in the main brake fluid passage 13 between the supply electromagnetic switching valve 17 and the wheel cylinder 14 and to apply a brake. The liquid return passage 29 is brought into a communicating state. Further, the pump drive motor 23 is driven to operate the pressurizing pump 24, and the brake fluid in the wheel cylinder 14 is passed from the main brake fluid passage 13 to the brake fluid return passage 29 through the electromagnetic switching valve 30 for discharge, and the reservoir 31 While a part of the pressure is stored in the damper tank 22 by the pressurizing pump 24. As a result, the brake fluid pressure in the wheel cylinder 14 decreases rapidly.

The auxiliary pump 25 operates simultaneously with the pressurizing pump 24 in accordance with the driving of the pump driving motor 23. However, since the electromagnetic switching valve 26 for acceleration slip is kept in a non-energized state, the auxiliary The brake fluid passage 20 is closed and the auxiliary pump 25 merely idles.

If it is determined that it is necessary to keep the brake fluid pressure in the wheel cylinder 14 as it is,
The control device 18 outputs a holding signal. Specifically, the supply electromagnetic switching valve 17 is energized, and the supply electromagnetic switching valve 17
Main brake fluid passage 13 between wheel cylinder 14
By shutting off the brake fluid pressure in the inside, the wheel cylinder 14 is held in a closed system to suppress a change in brake fluid pressure.

On the other hand, the control device 18 controls the driving wheel speed sensor 80
When it is determined based on a detection signal from the driven wheel speed sensor 81 or the like that an acceleration slip has occurred in the drive wheel and the brake fluid pressure in the wheel cylinders 14 _RL and 14 _RR needs to be increased, the control device 18 Outputs a pressure increase signal. Specifically, the electromagnetic switching valve 15 for braking slip and the electromagnetic switching valve 26 for acceleration slip are energized to close the electromagnetic switching valve 15 for braking slip and open the electromagnetic switching valve 26 for acceleration slip. At the same time, the pump drive motor 23 is driven to operate the pressurizing pump 24 and the auxiliary pump 25, and the auxiliary pump 25
The brake fluid is supplied from the sub brake fluid passage 20 into the pump chamber 41 of the pressurizing pump 24 via the electromagnetic switching valve 26 for acceleration slip, and the brake fluid is further supplied from the main brake fluid passage 13 by the pressurizing pump 24. The power is supplied to the wheel cylinders 14 _RL , 14 _RR via the supply electromagnetic switching valve 17, whereby idling of the rear wheels is suppressed, and the driving force can be efficiently transmitted from the rear wheels to the road surface.

If the control device 18 determines that there is a risk of turning spin occurring in the vehicle based on the detection signals from the steering angle sensor 82 and the yaw sensor 83, the front wheels and / or the turning wheels located outside the turning center are turned off. The brake fluid is supplied to the wheel cylinder 14 of the rear wheel located inside the center to stabilize the posture of the vehicle.

[0052]

According to the brake control device of the present invention, the driving phase of the plunger of the first reciprocating pump is shifted from the driving phase of the plunger of the second reciprocating pump, so that the plunger of the first reciprocating pump shifts the suction stroke. In this case, since the plunger of the second reciprocating pump is set to the discharge stroke, sufficient brake fluid for increasing the pressure of the wheel cylinder in the pump chamber of the first reciprocating pump in the second reciprocating cycle is supplied. Can be supplied from a pump. For this reason, it is possible to operate the second reciprocating pump at a low pressure while securing the boosting performance of the wheel cylinder, to reduce the load on the pump drive motor, and to reduce the size of the pump drive motor and the hydraulic unit. It is possible to improve vehicle mountability and reduce costs.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an embodiment of a brake control device according to the present invention.

FIG. 2 is a cross-sectional view illustrating a schematic structure of a brake control device illustrated in FIG.

FIG. 3 is a control block diagram in the embodiment shown in FIG. 1;

FIG. 4 is a conceptual diagram illustrating a suction stroke of a reciprocating pump to which the present invention is applied.

FIG. 5 is a conceptual diagram illustrating a discharge stroke of a reciprocating pump to which the present invention is applied.

[Description of Signs] 12 Master cylinder 13 Main brake fluid passage 14 Wheel cylinder 15 Electromagnetic switching valve for braking slip (first on-off valve) 17 Electromagnetic switching valve for supply 18 Control device 20 Sub brake fluid passage 23 Pump drive motor 24 Addition Pressure pump (first reciprocating pump) 25 Auxiliary pump (second reciprocating pump) 26 Electromagnetic switching valve for acceleration slip (second on-off valve) 29 Brake fluid return passage 30 Electromagnetic switching valve for discharge 31 Reservoir 33 Casing 36 Plunger 41 pump chamber 45 blind hole 52 suction valve plate 55 compression spring 58 plunger 63 pump chamber 65 annular gap 66 annular groove 67 communication hole

Claims (6)

[Claims] 1. A first on-off valve provided in a main brake fluid passage connecting a brake master cylinder and a brake wheel cylinder, and the main brake fluid between the first on-off valve and the brake wheel cylinder. A supply on-off valve provided in the passage, and a sub-opening having one end communicating with the main brake fluid passage between the supply on-off valve and the first on-off valve and the other end communicating with the brake master cylinder side. A first reciprocating pump provided in the brake fluid passage for discharging brake fluid toward the main brake fluid passage; and provided in the sub brake fluid passage between the first reciprocating pump and the brake master cylinder. And discharges the brake fluid toward the first reciprocating pump and shifts the driving phase of the plunger with respect to the driving phase of the plunger of the first reciprocating pump. A second reciprocating pump, a second on-off valve provided in the sub brake fluid passage between the second reciprocating pump and the brake master cylinder, a first reciprocating pump, and a second reciprocating pump. A discharge on-off valve provided in a brake liquid return passage having one end communicating with the sub-brake fluid passage between the reciprocating pump and the other end communicating with the brake wheel cylinder; A reservoir provided in the brake fluid return passage between the suction valve and the suction valve of the reciprocating pump, a pump driving motor for driving the first reciprocating pump and the second reciprocating pump, and an operation of the pump driving motor And control means for controlling the opening and closing of the first on-off valve, the supply on-off valve, the discharge on-off valve, and the second on-off valve in accordance with the operating state of the vehicle. Brake control device, characterized in that the. 2. The brake according to claim 1, wherein the driving phase of the plunger of the first reciprocating pump and the driving phase of the plunger of the second reciprocating pump are set substantially opposite to each other. Control device. 3. A driving phase of the plunger of the first reciprocating pump so that brake fluid is supplied from the second reciprocating pump into the pump chamber during a suction stroke of the plunger of the first reciprocating pump. 2. The brake control device according to claim 1, wherein a driving phase of the second reciprocating pump is shifted. 4. The pump according to claim 1, wherein the second reciprocating pump discharges a brake fluid toward a pump chamber of the first reciprocating pump. Brake control device. 5. The brake fluid return passage has one end communicating with a pump chamber of the first reciprocating pump via a suction valve of the first reciprocating pump.
The brake control device according to any one of the above. 6. The brake control device according to claim 1, wherein the driving state of the vehicle is a slip amount of a driving wheel.