KR101866009B1

KR101866009B1 - Hydraulic apparatus for vehicle and Method for controlling the same

Info

Publication number: KR101866009B1
Application number: KR1020160007616A
Authority: KR
Inventors: 김택조; 정순영
Original assignee: 현대자동차주식회사; 주식회사 만도
Priority date: 2016-01-21
Filing date: 2016-01-21
Publication date: 2018-07-04
Also published as: KR20170087708A

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a hydraulic device for a vehicle, and more particularly, to a hydraulic device for a vehicle and a control method thereof, which improves heterogeneity and improves hydraulic leak when releasing the hydraulic pressure.

Description

Technical Field [0001] The present invention relates to a hydraulic device for a vehicle,

Generally, when the AVH (Auto Vehicle Hold) operates, the Traction Control (TC) valve is closed to maintain the hydraulic pressure. However, if the operating HOLD current value of the TC valve is small, the pressing force of the valve is low and leakage occurs. On the contrary, if the current value becomes large, the problem of noise or the like may occur due to sudden operation.

Therefore, current control is performed during AVH operation, and the control pattern is taken to meet various conditions. If leakage occurs due to weak current, creep joint and reclamp will occur due to brake pressure drop, which causes the customer to feel uneasiness and noise.

Further, in order to prevent TC valve hydraulic leak, the current value is initially increased to increase the valve operating force, and then the current value is reduced by decreasing the current value so as to satisfy the target entry hydraulic pressure.

At this time, if the hold current value is increased to prevent leakage, the entry pressure is also increased, and the AVH must be operated only when the driver operates the brake pedal with a great force. Further, since a sense of heterogeneity is generated when the valve is released, there is a sense of heterogeneity due to abrupt pressure release, which has a limitation in increasing the current value. That is, the hydraulic leak can be prevented when the current value is increased, but there is a restriction in increasing the current value because a sudden pressure release causes a sense of shearing.

1. Korean Patent Publication No. 10-2013-0116096 2. Korean Patent Publication No. 10-2011-0132922

The present invention provides a hydraulic control apparatus for a vehicle and a control method therefor, which are provided to solve a problem according to the above background art, and which provide a current control pattern so as to prevent a leak, There is a purpose.

SUMMARY OF THE INVENTION The present invention provides a hydraulic device for a vehicle that provides a current control pattern so as to prevent leakage while preventing leakage due to abrupt pressure release.

The vehicular hydraulic system according to claim 1,

brake pedal;

A master cylinder for generating and applying an oil pressure by the biasing force of the brake pedal;

A hydraulic circuit having a plurality of valves for opening or closing the hydraulic pressure to supply or block the plurality of wheels; And

And a controller for controlling a drive valve current for opening or closing the plurality of valves so as to maintain or reduce the pressure corresponding to the hydraulic pressure.

At this time, the controller performs the depressurization mode or the hold mode according to the operation or release of the AVH (Auto Vehicle Hold), thereby decreasing or increasing the driving valve current.

In the hold mode, if the hold count is smaller than a predetermined first reference value, the rush pattern is applied to initially apply the drive valve current. If the hold count is larger than the first specific reference value, The driving valve current may be decreased while the hydraulic pressure is lowered, and then the driving valve current may be further increased in the pressure maintaining period.

In the case of the reduced pressure mode, when the pressure reduction count is smaller than a second specific reference value set in advance to gradually release the hydraulic pressure, the drive valve current is initially reduced to a large extent, And decreasing the drive valve current to a small value if the current value is larger than the reference value.

Also, the hold count may be increased by a cycle of 10 ms, and the first specific reference value may be 350 ms.

At this time, the decompression count is increased by a cycle of 10 ms, and the second specific reference value is 40 ms.

The plurality of valves may be traction control valves.

Further, the hydraulic circuit may be an electronic stability control (ESC) hydraulic circuit.

In addition, it is possible to downsize the driving valve current to 5 mA per 10 ms.

Also, it is possible that the driving valve current is greatly reduced by 150 mA for 40 ms.

Also, in the pressure maintaining period, the driving valve current may be maintained constant for a predetermined time.

On the other hand, another embodiment of the present invention includes an application step in which the master cylinder generates hydraulic pressure and applies it to the hydraulic circuit by the power of the brake pedal; A valve control step of the hydraulic circuit opening or closing the hydraulic pressure through a plurality of valves to supply or shut off the hydraulic pressure to a plurality of wheels; And a driving valve current adjusting step of controlling a driving valve current for opening or closing the plurality of valves so that the controller maintains or reduces the pressure corresponding to the hydraulic pressure. Can be provided.

At this time, the driving valve current adjusting step may include: a determining step of determining whether the controller operates or releases an automatic vehicle hold (AVH); And a decreasing step of decreasing or increasing the driving valve current by performing a pressure reducing mode or a holding mode according to a determination result.

In addition, in the case of the hold mode, the step of increasing / decreasing may include comparing a hold count with a predetermined first reference value that is set in advance; Performing a rush pattern for initially imparting the drive valve current to the initial value if the comparison result is smaller than the first specific reference value; If the hold count is greater than a first specific reference value, applying a driving valve current lower than the initial value so as to satisfy a target entry hydraulic pressure; And further increasing the driving valve current again in a pressure maintaining period after the application of the driving current.

The step of increasing / decreasing may further include: comparing, in the case of the reduced pressure mode, a reduced pressure count to a second specific reference value that is set in advance to stepwise release the hydraulic pressure; If it is smaller than the second specific reference value, lowering the drive valve current to a large extent initially; And decreasing the driving valve current to a small value if the reduced pressure count is greater than the second specific reference value as a result of the comparison.

According to the present invention, the hold current value can be raised to satisfy the target entry hydraulic pressure while preventing the hydraulic leak.

Another advantage of the present invention is that even when the hold current value is raised, the sense of heterogeneity can be removed.

1 is a structural block diagram of a hydraulic device for a vehicle according to an embodiment of the present invention.
Fig. 2 is a detailed configuration diagram of the vehicular hydraulic device shown in Fig. 1. Fig.
FIG. 3 is a flowchart illustrating a process of preventing a leak according to an embodiment of the present invention.
4 is a conceptual diagram for controlling a traction control valve current according to an embodiment of the present invention.
5 is a flowchart illustrating a process of controlling a traction control valve current according to another embodiment of the present invention.
6 is a conceptual diagram for controlling a traction control valve current according to another embodiment of the present invention.
Fig. 7 is a conceptual diagram of valve current control according to Figs. 3 to 6. Fig.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be construed as ideal or overly formal in meaning unless explicitly defined in the present application Should not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vehicle hydraulic apparatus and a control method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a structural block diagram of a hydraulic device for a vehicle according to an embodiment of the present invention. 1, the vehicular hydraulic system 100 includes a brake pedal 150, a master cylinder 130 for generating and applying hydraulic pressure by the biasing force of the brake pedal 150, A hydraulic circuit 160 having a plurality of valves for supplying or shutting off the valves 170-1 to 170-4 of the hydraulic circuit 160, a drive valve 160 for opening or closing the plurality of valves to maintain or reduce the pressure corresponding to the hydraulic pressure, A controller 110 for controlling the current, and the like.

Of course, a hydraulic booster 140 is also provided between the master cylinder 130 and the brake pedal 150. [ Further, a sensor 120 for detecting the hydraulic pressure of the master cylinder 130 is constructed. The hydraulic booster 140 functions to multiply the leg power of the brake pedal 150 of the driver.

When the driver depresses the brake pedal 150, the pressing force of the brake pedal 150 is transmitted to the hydraulic booster 140. The master cylinder 130 controls the braking pressure of the first to fourth wheels 170-1 to 170-4 in accordance with the pressure transmitted from the hydraulic booster 140 through the hydraulic circuit 160, To the brake calipers of the first and second brake units 170-1 to 170-4.

The hydraulic circuit 160 may be an electronic stability control (ESC) hydraulic circuit. In this case, wheel speed sensors (not shown) may be installed on the first to fourth wheels 170-1 to 170-4, respectively, for the ESC system.

Fig. 2 is a detailed configuration diagram of the vehicular hydraulic device shown in Fig. 1. Fig. 2, the hydraulic circuit 160 is connected to a master cylinder 130 that generates pressure by a brake booster 140 that doubles the driver's brake pedal 150, 170-1 to 170-4 (more precisely, the wheel brake).

To this end, the hydraulic circuit 160 includes a first hydraulic pressure channel 160-1 and a second hydraulic pressure channel 160-2. The first hydraulic pressure channel 160-1 connects the first port of the master cylinder 130 and the first and second wheels 170-1 and 170-2 to control hydraulic transmission. The second hydraulic pressure channel 160-2 connects the second port of the master cylinder 130 to the remaining two third and fourth wheels 170-3 and 170-4 to control hydraulic transmission.

At this time, the first hydraulic pressure channel 160-1 and the second hydraulic pressure channel 160-2 are installed compactly in a hydraulic block (not shown).

The first hydraulic pressure channel 160-1 and the second hydraulic pressure channel 160-2 control the braking hydraulic pressure transmitted to the two wheels 170-1 and 170-2, 170-3 and 170-4, And the oil or master cylinder 130 that has escaped from the first to fourth wheels 170-1 to 170-4 by driving of the motor 210 Pressure accumulators 215-1 and 215-2 for temporarily storing the oil escaping from the first to fourth wheels 170-1 to 170-4, and pumps 214-1 and 214-2 for sucking and pumping the oil, A main flow path 247a for connecting the discharge port of the pump 210 and the master cylinder 130 and an auxiliary flow path 248a for guiding the oil of the master cylinder 130 to be sucked into the inlet of the pumps 214-1 and 214-2 ) And the like.

A plurality of traction control valves 213-1 and 213-2 are associated with the upstream and / or downstream sides of the wheels 170-1 to 170-4, A normally open type (NO type) traction control valve 41 which is disposed on the downstream side of the wheels 170-1 to 170-4 and is maintained in a normally open state, Type (NC type) traction control valve. The opening and closing operations of the traction control valves 213-1 and 213-2 are performed by a controller 110 that senses the vehicle speed through a wheel speed sensor (not shown) disposed on each wheel 170-1 to 170-4 And the NC type traction control valve is opened in response to the pressure reduction braking so that the oil that has escaped from the wheels 170-1 to 170-4 is temporarily stored in the low pressure accumulators 215-1 and 215-2.

The pumps 214-1 and 214-2 are driven by the motor 210 to suck and discharge the oil stored in the low pressure accumulators 215-1 and 215-2 so that the hydraulic pressure is supplied to the first to fourth wheels 170-1 to 170-4 To the master cylinder 130 side.

A normally open type traction control valve is provided in the main passage 247a that connects the master cylinder 130 and the discharge ports of the pumps 214-1 and 214-2. The braking oil pressure generated in the master cylinder 130 during normal braking through the brake pedal 150 is transmitted to the first to fourth wheels 170-1 to 170-7 through the main oil passage 247a while maintaining the normally- -4) side.

The auxiliary flow path 248a is branched from the main flow path 247a to guide the oil of the master cylinder 130 to the inlet side of the pumps 214-1 and 214-2. Hydraulic shuttle valves (HSV: Hydraulic Shuttle Valves) 212-1 and 212-2 are provided to allow oil to flow only to the openings of the pumps 214-1 and 214-2. The electrically operated hydraulic shuttle valves 212-1 and 212-2 are installed in the middle of the auxiliary flow path 248a to be normally closed and operate to be opened in the TCS (Traction Control System) mode.

On the other hand, check valves 216-1 and 216-2 are installed at appropriate positions of the oil passage to prevent reverse flow of the oil.

The main flow path 247a is formed with relief valves 211-1 and 211-2 as traction control valves, and is normally open.

The traction control valve is installed in the middle of the hydraulic line connected to the master cylinder 130 and the wheel cylinders on the wheels 170-1 to 170-4. Such a traction control valve is wound with a solenoid coil, and when a current is supplied to the coil from the controller 110, the pressure for closing the flow path is adjusted according to the amount of the supplied current. That is, when the amount of current supplied to the traction valve increases, the magnetic field generated in the solenoid coil wound around the traction valve becomes large, and the force for closing the flow path becomes large. As the force for closing the flow path becomes greater, the oil discharged from the hydraulic pump is also transmitted to the wheel cylinders (not shown) of the first to fourth wheels 170-1 to 170-4, which increases the braking pressure .

FIG. 3 is a flowchart illustrating a process of preventing a leak according to an embodiment of the present invention. Referring to FIG. 3, in the driving valve current adjusting step, the controller determines whether or not the AVH (Auto Vehicle Hold) operation is released (steps S310 and S320). An Automatic Vehicle Hold (AVH) system is a system for realizing signal waiting or simple stopping in a complex urban center or a ramp where frequent parking lots occur. Generally, it is usually indicated as AUTO (ⓟ) in a cluster (CLUSTER) or a switch (SWITCH).

If the operation condition of the automatic vehicle hold is satisfied according to the determination result in step S320, the hold mode is performed (step S330).

As the hold mode is performed, the hold count is increased (about 10 ms cycle) and compared with a first predetermined reference value (about 350 ms) that is set in advance (step S350).

As a result of the comparison in step S350, if the hold count is equal to or less than the first specific reference value, a rush pattern is applied to initially apply the drive valve current to the initial value (step S370).

Alternatively, if the hold count is greater than the first specific reference value (about 350 ms) as a result of the comparison in step S350, the drive valve current is lowered to be lower than the initial value so as to satisfy the target entry hydraulic pressure, The drive valve current is further increased again in the sustain period (step S380).

4 is a conceptual diagram for controlling a traction control valve current according to an embodiment of the present invention. Referring to FIG. 4, the relationship between the master cylinder (M / C) pressure, the wheel pressure, the pressure holding interval, and the valve current for driving the Traction Control (TC) valve is shown.

In other words, at the beginning of the pressure maintenance interval, the drive valve current is increased to change the pressure to maintain the pressure at a higher force. Therefore, the pressure holding ability can be improved and the tendency of the pressure leak can be reduced.

That is, in order to prevent a hydraulic leak of the traction control valve, the valve operating current is initially given large value to increase the valve operating force (410), and then the driving valve current value is reduced to satisfy the target entry hydraulic pressure ), The driving valve current value is increased again in the pressure holding period (430).

5 is a flowchart illustrating a process of controlling a traction control valve current according to another embodiment of the present invention. Referring to FIG. 5, the controller (110 of FIG. 1) determines whether the release condition is satisfied during the operation of automatic vehicle hold (steps S510 and S520).

If it is determined in step S520 that the cancellation condition of the automatic vehicle hold is satisfied, the pressure reducing mode is performed (step S530). As the decompression mode is performed, the decompression count is increased (about 10 ms cycle) to stepwise release the hydraulic pressure, and is compared with a predetermined second reference value (about 40 ms) (step S540).

If the comparison result is less than the second specific reference value in step S540, the drive valve current is largely lowered in order to secure responsiveness in an initial stage (step S570).

Otherwise, if it is determined in step S540 that the pressure reduction count is larger than the second specific reference value, the driving valve current is decreased to a small value according to the required pressure reduction gradient (step S560).

6 is a conceptual diagram for controlling a traction control valve current according to another embodiment of the present invention. Referring to FIG. 6, when the automatic vehicle hold (AVH) is released, the drive valve current value is initially reduced to a large extent and then downwardly (step 640) in a stepwise manner in the next step. Therefore, it is possible to reduce the current value without giving a sense of heterogeneity. That is, the release slope is biased to prevent the wheel pressure from decreasing in reactivity when AVH is released due to current compensation in the pressure maintenance interval. Particularly, in the compensated current section, a fast current slope is applied to improve wheel pressure responsiveness.

Fig. 7 is a conceptual diagram of valve current control according to Figs. 3 to 6. Fig. Referring to FIG. 7, when the automatic vehicle hold (AVH) is released, the drive valve current is decreased to 150 mA for 40 ms, which is a large value, and then decreased to 5 mA per 10 ms.

100: Hydraulic system for automobile
120: sensor
130: master cylinder
140: Hydraulic booster
150: Pedal
160: Hydraulic circuit
170-1 to 170-4: First to fourth wheels

Claims

brake pedal;
A master cylinder for generating and applying an oil pressure by the biasing force of the brake pedal;
A hydraulic circuit having a plurality of valves for opening or closing the hydraulic pressure to supply or block the plurality of wheels; And
And a controller for controlling a drive valve current for opening or closing the plurality of valves so as to maintain or reduce the pressure corresponding to the hydraulic pressure,
The controller performs a depressurization mode or a hold mode according to the operation or release of AVH (Auto Vehicle Hold), thereby decreasing or increasing the drive valve current,
In the hold mode, if the hold count is smaller than or equal to a first specific reference value that is set in advance, a rush pattern for giving the drive valve current to a large initial value is performed. If the hold count is larger than the first specific reference value, Wherein the drive valve current is further decreased while the pressure is maintained lower than the initial pressure so as to satisfy the following equation: < EMI ID = 1.0 >

delete

The method according to claim 1,
In the case of the reduced pressure mode, when the pressure reduction count is smaller than or equal to a second specific reference value that is set in advance for releasing the hydraulic pressure stepwise, the driving valve current is initially reduced to a large extent, The drive valve current is decreased to a small extent.

The method according to claim 1,
Wherein the hold count is increased by a cycle of 10 ms, and the first specific reference value is 350 ms.

5. The method of claim 4,
Wherein the decompression count is increased in a cycle of 10 ms, and the second specific reference value is 40 ms.

The method according to claim 1,
Wherein the plurality of valves are traction control valves.

The method according to claim 1,
Wherein the hydraulic circuit is an ESC (Electronic Stability Control) hydraulic circuit.

The method according to claim 6,
And the driving valve current is decreased down to 5 mA per 10 ms.

The method according to claim 6,
Wherein the driving valve current is significantly reduced to 150 mA for 40 ms.

The method according to claim 1,
And the drive valve current is kept constant for a predetermined time in the pressure maintaining period.

An application step in which the master cylinder generates hydraulic pressure and applies the generated hydraulic pressure to the hydraulic circuit by the power of the brake pedal;
A valve control step of the hydraulic circuit opening or closing the hydraulic pressure through a plurality of valves to supply or shut off the hydraulic pressure to a plurality of wheels; And
And a drive valve current adjusting step of controlling a drive valve current for opening or closing the plurality of valves so that the controller maintains or depressurizes the pressure corresponding to the hydraulic pressure,
Wherein the driving valve current adjusting step comprises:
A determination step of determining whether the controller operates or releases an automatic vehicle hold (AVH); And
And decreasing or increasing the driving valve current by performing a pressure reducing mode or a holding mode according to a determination result,
The step of increasing /
Comparing the hold count with a first predetermined reference value set in advance in the case of the hold mode;
Performing a rush pattern that gives the drive valve current at a large initial value if the comparison result is smaller than or equal to the first specific reference value;
If the hold count is greater than a first specific reference value, applying a driving valve current lower than the initial value so as to satisfy a target entry hydraulic pressure; And
And further increasing the driving valve current again in a pressure holding period after the application of the driving current is continued.

delete

13. The method of claim 12,
The step of increasing /
In the case of the reduced pressure mode, comparing the pressure reduction count to a second predetermined reference value that is set in advance to stepwise release the hydraulic pressure;
If the comparison result is smaller than or equal to the second specific reference value, the step of initially lowering the drive valve current to a large extent; And
And decreasing the driving valve current to a small value if the depressurization count is greater than a second specific reference value as a result of the comparison.