KR100476028B1 - Piezo-valve modulator and anti-lock brake system comprising the same - Google Patents

Abstract

The present invention relates to a piezoelectric valve modulator using a piezoelectric valve and an ABS using the same, in the modulator for controlling the pressure of a hydraulic circuit, each tip portion is located at a mutually opposite position on one side of a space part provided therein. A body having a first nozzle and a second nozzle mounted to have a body and having a discharge port connected to an input side of the hydraulic pump, and fixed at the other side such that a free end of one side is positioned between the first nozzle and the second nozzle A piezoelectric valve having a stage fixed to a predetermined position of the space part and including a piezoelectric actuating member configured to selectively close the first nozzle or the second nozzle when the electric field is applied; And a first cylinder portion reciprocating by a working fluid controlled by the piezoelectric valve and a second cylinder portion integrated with the first cylinder portion by a piston rod and filled with heterogeneous fluids. By providing an anti-lock brake system (ABS) comprising a piezoelectric valve modulator comprising an assembly, and a piezoelectric valve modulator including a piezoelectric valve modulator and a brake hydraulic circuit, thereby providing a quick brake response and braking efficiency To reduce the number of components and enable efficient production.

Description

PIEZO-VALVE MODULATOR AND ANTI-LOCK BRAKE SYSTEM COMPRISING THE SAME

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric valve modulator using a piezoelectric valve and an ABS using the same. In particular, the present invention is operated by a pressure difference between two nozzles generated by controlling the displacement of piezo-material by controlling the strength of an applied electric field. A piezoelectric valve modulator including a piezoelectric valve that controls the direction and pressure of the fluid, and the piezoelectric valve modulator enables continuous control of the hydraulic pressure required for braking, thereby improving braking efficiency and increasing the sensitivity or sense of the brake pedal. The present invention relates to an ABS including a piezoelectric valve modulator, which makes it possible to achieve fast brake response characteristics.

In general, a vehicle is provided with a brake system for decelerating or stopping the vehicle's speed when driving. When the driver presses the brake pedal to reduce or stop the vehicle speed while driving, the brake pedal is operated by the driver. The hydraulic pressure is generated by the master cylinder by the mechanical force converted by the brake pedal.

The hydraulic pressure generated by the master cylinder is transmitted to each wheel cylinder through the brake hydraulic line, and the wheel cylinder received hydraulic pressure through the brake hydraulic line operates the piston to pressurize the brake pad or drum to rotate the wheel. By slowing down, the vehicle stops.

However, this conventional brake system has a problem in that the attitude stability and steering ability of the vehicle are lost as each wheel is momentarily locked.

In order to solve this problem, an antilock brake system (ABS) has been developed. In recent years, vehicles equipped with ABS have been widely used.

ABS controls the hydraulic pressure applied to the wheel cylinders provided on each wheel to rapidly decrease or increase according to the rotational state of each wheel, thereby preventing each wheel from being locked during braking and maintaining steering stability at all times. At the same time, it allows the vehicle to stop at the shortest distance.

In order to enable the braking as described above, ABS is controlled by an electronic control unit (ECU), and ECU detects the speed of each wheel by the signal detected from the wheel speed sensor, calculates the slip ratio therefrom, and then It is configured to provide an appropriate braking force by controlling the ABS so that the hydraulic pressure applied to the wheel cylinder is increased or decreased based on the rate.

1 is a configuration diagram of an ABS brake system according to the prior art, a brake pedal 10 to be operated by the driver during braking, and a brake booster for amplifying the force transmitted from the brake pedal 10 to generate a hydraulic action force ( 20) and a master cylinder (30).

In addition, the solenoid valve 50, 52 for supplying the generated hydraulic pressure to the wheel cylinder (not shown) for pressurizing the brake pad 40 of each wheel, and the hydraulic fluid for brake discharged from the wheel cylinder to a predetermined pressure Accumulator 60, which is temporarily stored while being maintained, and pump 70 for pumping brake fluid stored in the accumulator 60 to the master cylinder 30 or the wheel cylinder, are supplied when the pump 70 is driven. It consists of the damper chamber 80 and the check valve 90 for reducing the pulsation of hydraulic oil.

The solenoid valve (50) (52) is to control the hydraulic pressure of the hydraulic oil generated in the master cylinder (30) and delivered to the wheel cylinder. It is disposed at the inlet side and the outlet side of the wheel cylinder, respectively, and the solenoid valve 50 is a normal open type (NO) which maintains an off state, and the other solenoid valve 52 maintains an off state. Normal closed type (NC).

ABS brake system having such a configuration is that when the driver brakes the vehicle by stepping on the brake pedal 10 during braking, both the solenoid valve 50 and the solenoid valve 52 are 'off', so that the open and closed states are respectively. The hydraulic pressure acts on the wheel cylinder by maintaining.

At this time, when excessive slip ratio is generated, the ABS braking is performed according to the ABS control mode divided into the decompression mode, the maintenance mode, and the boost mode.

That is, in the depressurization mode, the electronic controller accumulates the hydraulic oil flowing into the wheel cylinder by turning the solenoid valve 50 'on' to a closed state and turning the solenoid valve 52 'on' to an open state. To be discharged to the side.

When switching to the maintenance mode from the depressurized state, the electronic controller closes the solenoid valve 50 by turning it on and closes the solenoid valve 42 by turning it off so that the hydraulic pressure acting on the wheel cylinder 2 is not changed. Will be maintained.

When switching from the holding mode to the boosting mode, the electronic control unit turns off both the solenoid valve 50 and the other solenoid valves 52, and puts them in an open state and a closed state, respectively, so that the pressure of the hydraulic oil acts on the wheel cylinder. Do it.

As such, when switching from the maintenance mode to the boost mode, the solenoid valve 50 is switched from the on state to the off state by switching from 'on' to 'off', whereby pulsation flow occurs in the hydraulic oil.

That is, as the driving current applied to the solenoid valve 50 is cut off while being switched from the maintenance mode to the boost mode, the flow path communicating with the wheel cylinder is opened so that the hydraulic oil flows from the master cylinder 30 to the wheel cylinder side through the hydraulic line. do.

At this time, the master cylinder 30 side is a high pressure and the wheel cylinder side is formed at a relatively low pressure to generate a pressure difference, the pulsating flow appears in the process of the hydraulic oil is rapidly introduced into the wheel cylinder by this pressure difference, such a pulsating flow Is transmitted to the wheel cylinder as it is, there is a problem that makes the braking action unstable and cause discomfort to the driver.

As described above, the ABS according to the related art controls the solenoid valve in such a manner that the electronic controller supplies or cuts off the driving current to turn on and off, thereby causing a pulsation flow caused by a momentary pressure difference.

In addition, due to this problem, there is another problem that may not only reduce the sense of the brake pedal during braking but also lower the braking force, which may threaten the safety of the occupant.

In order to solve such problems of the prior art,

An object of the present invention includes a piezoelectric valve for controlling the direction and pressure of the working fluid by using the pressure difference generated in accordance with the change in the strength of the electric field applied to the piezoelectric material, so that the hydraulic pressure transmitted to each wheel during braking It is to provide a piezoelectric valve modulator that can control the continuously.

Another object of the present invention is to provide an ABS having a piezoelectric valve modulator, which is equipped with a piezoelectric valve modulator, which enables quick brake response and improves braking efficiency, and reduces economical components.

The present invention for realizing this,

In the modulator for controlling the pressure of the hydraulic circuit,

A body having a first nozzle and a second nozzle, each tip portion of which is mounted at a mutually opposite position on one side of the space portion provided therein to have a predetermined interval, and having a discharge port connected to an input side of the hydraulic pump;

The fixed end of the other side is fixed to a predetermined position of the space part so that one free end is located between the first nozzle and the second nozzle, and the free end portion selectively selects the first nozzle or the second nozzle when an electric field is applied. A piezoelectric valve including a closed piezoelectric operation member; And

Dual-type cylinder having a first cylinder portion reciprocating the piston by the working fluid controlled by the piezoelectric valve, and a second cylinder portion which is integrally interlocked with the first cylinder portion by the piston rod and filled with different kinds of fluids. It provides a piezoelectric valve modulator comprising an assembly.

And the present invention,

An antilock brake system (ABS) including the above piezoelectric valve modulator and a brake hydraulic circuit whose pressure is controlled by the piezoelectric valve modulator.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the present invention, the same reference numerals are used for the same configuration as the prior art.

As illustrated in FIG. 2, the piezoelectric valve modulator 200 according to the present invention includes one piezoelectric valve 250 and one dual type cylinder assembly 300.

The piezoelectric valve 250 is the first nozzle 223 and the second nozzle 224 and the hydraulic pump 70 is mounted so that each tip portion has a predetermined interval at mutually opposite positions of one side of the space provided therein Body 210 having a discharge port 225 connected to the input side of the other side and the fixed end of the other side so that the free end of one side is located between the first nozzle 223 and the second nozzle 224 The free end portion is fixed to a predetermined position of the negative portion when the electric field is applied to the piezoelectric operation member 230 to selectively close the first nozzle 223 or the second nozzle 224.

As shown in FIGS. 2 and 6, the dual type cylinder assembly 300 has two different kinds of working fluids flowing therein and is controlled by the working fluid controlled by the piezoelectric valve 250. The first cylinder portion 110 to which the piston 120 reciprocates, and the second cylinder portion 320 integrated with the first cylinder portion 110 and the piston rod 130 to be interlocked and filled with different kinds of fluids. It is composed.

Two pipes 241 and 242 branched from the output side of the hydraulic pump 70 are connected to the first nozzle 223 and the second nozzle 224, respectively, and the orifices 243 and 244 are respectively disposed on the pipes. Is installed. The first nozzle 223 is connected to the upper portion of the piston 120 of the first cylinder part 110 by a pipe, and the second nozzle 224 is the piston 120 of the first cylinder part 110. It is connected to the lower portion, the discharge port 225 formed in the body 210 of the piezoelectric valve 250 is connected to the input side of the hydraulic pump 70 to form a hydraulic circuit.

As an example of the piezoelectric valve 250, as shown in FIG. 3, a plate 227 having a predetermined length and a piezoelectric ceramic plate 229 attached to upper and lower portions of the plate 227, respectively. A piezoelectric valve 250 'comprising a piezoelectric actuating member 230' is used.

The piezoelectric actuating member 230 ′ is generally installed such that the free end portion maintains a minute gap with the first nozzle 223 and the second nozzle 224 about tens of microns, respectively, and the plate 227 is The free end of the piezoelectric actuating member 230 ′ is formed of a flexible material which is easy to bend, and is pulled or compressed by the piezoelectric ceramic plate 229 attached to the upper and lower surfaces of the plate 227 when the electric field is applied. By bending to one side, the first nozzle 223 or the second nozzle 224 is selectively closed.

As another embodiment of the piezoelectric valve 250, as shown in FIG. 4, a rigid plate 237 having a predetermined length and a piezoelectric ceramic film mounted on upper and lower sides of the fixed end side of the rigid plate 237, respectively. A body further comprising a piezoelectric actuating member 230 " made of a laminated plate 239 and a pair of mutually opposing guide members 215 for guiding stretching in the thickness direction of each of the piezoelectric ceramic laminated sheets 239 ( A piezoelectric valve 250 "including 210" may be used.

Also in this case, the piezoelectric actuating member 230 " is usually installed such that the free end portion maintains a minute gap of about several tens of microns, respectively, with the first nozzle 223 and the second nozzle 224, and the rigid body The plate 237 is formed of a material having rigidity that is difficult to bend, and when the piezoelectric ceramic laminated plate 239 mounted on the fixed end side of the rigid plate 237 is applied with an electric field, the plate 237 has a thickness direction in the guide member 215. Due to the expansion or contraction in a straight line toward the rigid plate 237 is raised and its free end selectively closes the first nozzle 223 or the second nozzle (224).

Referring to the dual type cylinder assembly 300 in more detail, as shown in Figure 6, the piston 120 is located in the first cylinder portion 110, the rod 130 of the piston 120 is The second cylinder part 320 extends into the inside. The second cylinder part 320 is filled with heterogeneous hydraulic oil 310 used as a working fluid of a hydraulic circuit other than the working fluid of the piezoelectric valve modulator 200, and a piston rod located therein. An end portion of 130 serves as a plunger.

That is, when an electric field is applied to the piezoelectric valve 250 by an electronic control unit (ECU) or the like, a pressure difference occurs at both ends of the piston 120, and the force caused by the pressure difference is generated by the piston rod 130. The pressure of the other hydraulic circuit is adjusted by pressurizing or reducing the hydraulic oil 310 delivered to the cylinder part 320 and filled therein. In other words, the dual type cylinder assembly 300 is to serve as an interface for connecting the operation of the two hydraulic circuits.

The piezoelectric valve modulator 200 as described above is a pressurizing part composed of a hydraulic pump 70 for pressurizing a working fluid, a plurality of check valves 90, an accumulator 60, and the like installed before and after the hydraulic pump 70. 500 to form a complete hydraulic circuit.

In more detail with respect to the pressurization portion, as shown in Figure 2, the first and second check valves 90, 90 'so that only one-way flow on the input side and the output side of the hydraulic pump 70, respectively It is installed to provide a continuous hydraulic pressure to supply to the piezoelectric valve 250 side, the output side is provided with a damper chamber 80 and the input side is configured to prevent the sudden pressure change.

The hydraulic pump 70 may be used a variety of known hydraulic pump, preferably a piezoelectric hydraulic pump 70 'described below may be used.

The piezoelectric hydraulic pump 70 'operates to reciprocate the diaphragm 75 provided in the body 72 by the vibrator 71 which vibrates according to a signal applied from the electronic control device, thereby continuously operating hydraulic pressure. Supply.

That is, the hydraulic oil supplied from the input side with the accumulator 60 due to the change in pressure generated by the operation of the diaphragm 75 is prevented from backflow by the first check valve 90, the second check valve 90 ') Prevents the hydraulic oil discharged to the output side provided with the damper chamber 80 at the high pressure to flow back to the pump.

The vibrator 71 is also formed of a piezoelectric material that generates vibration as an electric field is applied.

The piezo-material is a smart material, which is combined with an existing structure to convert the deformation of a material generated by physical force or pressure due to the extreme charge phenomenon of the polymer into electrical energy. Conversely, it has the function of converting electrical energy back into physical energy such as deformation of a material.

That is, the piezoelectric material performs tensile or compressive deformation under electric field load, and continuous control is possible by changing the size of the electric field. In addition, the piezoelectric material has a very fast reaction speed of about several ms, and has a characteristic of exhibiting a continuous and reversible response to an electric field load.

Therefore, the piezoelectric actuating member 230 formed of the piezoelectric material by controlling the strength of the electric field selectively closes the first nozzle 223 or the second nozzle 224, thereby generating a pressure difference on both sides. The pressure difference is acted as a power to reciprocate the piston 120 of the dual cylinder assembly 300.

For reference, the above-mentioned close is not limited to the dichotomous expression in contrast to the open, and usually the free end of the piezoelectric actuating member 230 is the first nozzle 223 and the first. It is maintained at equal intervals with the tip portion of the two nozzles 224, it means that the approach to the tip portion of one nozzle when the electric field is applied and finally closes by adjusting the strength of the electric field. In addition, the pressure difference does not occur between the two nozzles only when the nozzle on one side is closed, the pressure difference occurs at the same time as the unbalance of the gap occurs, the pressure difference is also adjusted by the gap. Of course, it is possible to obtain the maximum pressure difference in a state in which the nozzle on one side is completely closed.

Referring to the operation of the piezoelectric valve modulator 200 as described above in more detail, for example, by applying a controlled electric field to the piezoelectric actuating member 230 of the piezoelectric valve 250, the free end of the When the two nozzles 224 are closed, the second nozzle 224 is placed at a relatively high pressure as compared with the first nozzle 223, so that the hydraulic oil supplied from the hydraulic pump 70 is 1 is supplied to the lower portion of the piston 120 of the cylinder unit 110 to raise the piston (120). Hydraulic oil of the upper portion of the piston 120 of the first cylinder portion 110 discharged as the piston 120 rises is introduced into the piezoelectric valve body 210 through the first nozzle 223 which is in an open state, and discharged. The port 225 leads back to the hydraulic pump 70.

In this process, the piston rod 130 pressurizes the hydraulic oil 310 inside the second cylinder 320 to increase the pressure of the hydraulic circuit using the hydraulic oil 310 as the working fluid. In addition, it is possible to adjust the pressing force by controlling the electric field applied to the piezoelectric valve 250 even during pressurization.

On the contrary, when the controlled electric field is applied to the piezoelectric actuating member 230 of the piezoelectric valve 250 to close the first nozzle 223 having the free end thereof located thereon, the second nozzle is disposed on the first nozzle 223 side. When compared with the (224) side is placed in a relatively high pressure state, therefore, the hydraulic oil supplied from the hydraulic pump 70 is supplied to the upper portion of the piston 120 of the first cylinder portion 110 to the piston 120 Descended. Hydraulic oil of the lower part of the piston 120 of the first cylinder part 110 discharged as the piston 120 descends is introduced into the piezoelectric valve body 210 through the second nozzle 224 which is in an open state. The discharge port 225 leads to the hydraulic pump 70 again.

Also, in this process, as the piston rod 130 is lowered, the hydraulic oil inside the second cylinder 320 is placed under a reduced pressure, and the pressure of the hydraulic circuit using the hydraulic oil 310 as the working fluid is lowered. do.

The piezoelectric valve modulator 200 is provided with orifices 243 and 244 in the hydraulic pump side pipes 241 and 242 of the nozzles 223 and 224, respectively. Serves as a fixed pressure drop resistance to maximize the pressure difference that can be obtained by adjusting the pressure and flow rate of the pressurized hydraulic oil supplied from the hydraulic pump 70, and serves to minimize the energy loss. That is, it is possible to minimize the amount of hydraulic oil which is supplied from the hydraulic pump 70 in the state in which the low pressure relative to the nozzle of one side is returned to the input side of the hydraulic pump directly through the low pressure side nozzle. In addition, the orifices 243 and 244 act to allow a greater pressure to act on the high pressure side due to the pressure difference generated between both ends, thereby increasing the output absolute value of the dual cylinder assembly 300 that can be provided.

The piezoelectric valve modulator 200 as described above may be applied to perform rapid and continuous pressure control in connection with various hydraulic circuits requiring continuous pressure regulation. For example, it is possible to be applied to technologies such as ABS, traction control system (TCS), brake intervention traction control (BITC), electronic braking apportioning (EVA), vehicle dynamic control (VDC), and the like.

Hereinafter, the anti-lock brake system ABS including the piezoelectric valve modulator 200 according to the present invention will be described through a preferred embodiment.

As shown in FIG. 2, the ABS according to the present invention includes the ER valve modulator 200 and the brake hydraulic circuit according to the present invention described above.

The brake hydraulic circuit corresponds to a well-known technique that can be easily seen in a general hydraulic brake, but may be provided in various forms, but basically the mechanical force generated by the pedaling force of the driver and amplified by the booster 20. It includes a master cylinder 30 for converting the hydraulic pressure and a wheel cylinder (not shown) for mechanically pressing the brake pad 40 receives the hydraulic pressure.

The second cylinder part 320 of the piezoelectric valve modulator 200 is connected to the brake hydraulic circuit to pressurize or depress a wheel cylinder (not shown) as necessary.

Meanwhile, the valve assembly 400 for mode selection may be provided on a pipe connecting the second cylinder part 320 and the wheel cylinder of the dual type cylinder assembly 300.

The mode selection valve assembly 400 is a solenoid valve 410 and the check valve 420 is configured in parallel, that is, when the ABS mode is required to open the solenoid valve 410, and vice versa In this way, the ABS mode can be selectively used.

Referring to the operation of the ABS including the piezoelectric valve modulator according to the present invention configured as described above are as follows.

The hydraulic pressure required for the braking force of the brake system is primarily generated by the driver's pedal effort, and at the same time, the ECU detects the speed of each wheel based on a signal detected from the wheel speed sensor and calculates a slip ratio therefrom. By calculating the hydraulic pressure required for the wheel cylinder based on the slip ratio and applying a control signal to the piezoelectric valve modulator 200, the hydraulic pressure acting on the wheel cylinder to pressurize the brake pad is increased or decreased.

When an increase in the hydraulic pressure acting on the wheel cylinder is required, a controlled electric field is applied to the piezoelectric valve 250 so that the free end of the piezoelectric actuating member 230 approaches the direction in which the second nozzle 224 is closed. The difference is generated, and thus the flow of hydraulic oil pressurized by the hydraulic pump 70 immediately leads to the lower portion of the first cylinder portion 110 to raise the piston 120. The hydraulic oil discharged from the upper portion of the first cylinder part 110 by the rise of the piston 120 flows into the body 210 of the piezoelectric valve 250 through the first nozzle 223 placed in a relatively low pressure state. Again the discharge to the input side of the hydraulic pump (70).

In this process, the piston rod 130 pressurizes the hydraulic oil 310 inside the second cylinder 320 to increase the pressure acting on the wheel cylinder so that a greater braking force may be applied to the brake pad. In addition, it is possible to continuously and elastically adjust the applied pressure by controlling the strength of the electric field applied to the piezoelectric valve 250 even during pressurization.

On the contrary, when a reduction in hydraulic pressure acting on the wheel cylinder is required, such as when slip is sensed, the free end of the piezoelectric actuating member 230 approaches in the direction of closing the first nozzle 223 as opposed to pressing. By applying a controlled electric field, a high pressure side and a low pressure side generate a pressure difference. The flow of hydraulic oil pressurized by the hydraulic pump 70 is then directed to the upper portion of the piston 120 of the first cylinder unit 110. Lower the piston 120. The hydraulic oil discharged from the lower part of the first cylinder part 110 by the lowering of the piston 120 flows into the body of the piezoelectric valve 250 through the second nozzle 224 which is in a relatively low pressure state, and then the hydraulic pump again. It is discharged to the input side of 70.

In this process, the piston rod 130 is to reduce the pressure of the hydraulic oil 310 in the second cylinder 320, so that the pressure acting on the wheel cylinder is lowered to cope with a phenomenon such as slip.

In addition, the pressurization and depressurization actions as described above are instantaneously switched by controlling the electric field applied by the ECU so that the pressurization and depressurization can be repeatedly and continuously provided. This becomes feasible because the piezoelectric material has a fast response to electric fields.

On the other hand, as shown in Figures 2 and 6, in the case of having a mode control valve assembly 400, depending on the opening and closing of the solenoid valve 410 it is possible to selectively control the ABS mode or the normal braking mode. That is, as a result of analysis of the vehicle driving state in the ECU, when the use of the ABS mode is unnecessary, the hydraulic pressure by the piezoelectric valve modulator 200 is blocked from being transmitted to the brake hydraulic circuit, and the solenoid valve 410 is closed if necessary. Open so that the pressure in the state controlled by the piezoelectric valve modulator 200 is transmitted to the brake hydraulic circuit.

Like ABS including the piezoelectric valve modulator 200 as described above, the piezoelectric valve modulator 200 may be applied to various equipment related to braking and driving of transportation equipment such as automobiles and aircrafts. In the case of a vehicle, since the electric field loaded on each axle can be adjusted individually, it is possible to apply to technologies such as TCS, BICT, EBA, VDC as well as ABS as described above.

And because it uses electrical mechanisms rather than mechanical mechanisms, it can be applied to next-generation intelligent braking systems such as autonomous vehicles and driverless vehicles.

As described above, the present invention provides a piezoelectric valve modulator including a piezoelectric valve capable of generating a pressure difference by selectively closing the first nozzle and the second nozzle by controlling the piezoelectric operation member formed of the piezoelectric material only by changing the strength of the applied electric field. In addition, by providing an ABS including a piezoelectric valve modulator, it is possible to continuously control the hydraulic pressure required for the actual braking pressure of the vehicle, and to improve the braking force to reduce the risk of an accident. In addition, it is possible to increase the sensitivity or the sense of the brake pedal, and also have the effect of enabling efficient production by reducing the number of components while obtaining a quick response response of the brake. That is, it has the advantages of high performance, high efficiency and low cost.

While the invention has been shown and described in connection with specific embodiments, it is conventional in the art that various design changes and variations are possible without departing from the spirit and scope of the invention as indicated by the claims. Anyone with knowledge will know it easily.

1 is a block diagram showing an ABS brake system of a vehicle according to the prior art,

2 is a block diagram showing an ABS brake system including a piezoelectric valve modulator according to the present invention;

3 is a longitudinal sectional view showing a piezoelectric valve constituting a piezoelectric valve modulator according to an embodiment of the present invention;

4 is a longitudinal sectional view showing a piezoelectric valve constituting a piezoelectric valve modulator according to another embodiment of the present invention;

5 is an enlarged cross-sectional view of portion 'A' of FIG. 2;

6 is a block diagram showing an ABS brake system including a piezoelectric valve modulator according to another embodiment of the present invention,

FIG. 7 is an enlarged cross-sectional view of a portion 'B' of FIG. 6;

* Brief description of symbols for the main parts of the drawings *

70: hydraulic pump 71: vibrator

75: diaphragm 110: first cylinder

120: piston 130: piston rod

200: piezoelectric valve modulator 230: piezoelectric operating member

223: first nozzle 224: second nozzle

225: discharge port 243, 244: orifice

250: piezoelectric valve 300: dual type cylinder assembly

320: second cylinder portion 400: the mode control valve assembly

Claims (11)

In the modulator for adjusting the pressure of the hydraulic circuit, It is provided with a first nozzle 223 and a second nozzle 224 to be mounted so that each tip portion has a predetermined interval at mutually opposite positions of one side of the space provided therein and connected to the input side of the hydraulic pump 70 The body 210 having the discharge port 225 and a fixed end of the other side is fixed to a predetermined position of the space portion so that the free end of one side is located between the first nozzle and the second nozzle, the free when the electric field is applied. A piezoelectric valve 250 including a piezoelectric actuating member 230 whose end portion selectively closes the first nozzle or the second nozzle, and The first cylinder unit 110 is reciprocated by the working fluid controlled by the piezoelectric valve 250, and the first cylinder unit 110 and the piston rod 130 is integrated to cooperate with Piezoelectric valve modulator comprising a dual-type cylinder assembly 300 having a second cylinder portion 320 is filled with different kinds of fluid. The method of claim 1, The first nozzle 223 is connected to the output side of the hydraulic pump and one side of the piston 120 of the first cylinder 110, the second nozzle 224 is the output side of the hydraulic pump and the first cylinder ( 110 is connected to the other side of the piston, the piezoelectric valve modulator characterized in that the orifice (243) (244) for a fixed pressure drop is provided on each of the hydraulic pump (70) side pipe. The method of claim 2, The piezoelectric operation member (230 ') is a piezoelectric valve modulator, characterized in that consisting of a plate (227) having a predetermined length, and a piezoelectric ceramic plate (229) attached to the upper and lower portions of the plate. The method of claim 2, The piezoelectric actuating member 230 "includes a rigid plate 237 having a predetermined length, and a piezoelectric ceramic laminated plate 239 mounted to upper and lower portions of the fixed end side of the rigid plate, respectively. The body 210 "further includes a pair of mutually opposing guide members 215 for guiding stretching in the thickness direction of the piezoelectric ceramic laminated plate 239. The method of claim 2, The hydraulic pump is a piezoelectric hydraulic pump 70 for continuously supplying hydraulic pressure by operating the diaphragm 75 provided inside the body 72 by a vibrator 71 vibrating according to a signal applied from an electronic controller. ') Is a piezoelectric valve modulator. Discharge ports connected to the input side of the first nozzle 223 and the second nozzle 224 and the hydraulic pump 70 are mounted so that each tip portion has a predetermined interval in the mutually opposite position of one side of the space provided therein The body 210 having a 225 and a fixed end of the other side is fixed to a predetermined position of the space portion so that the free end of one side is located between the first nozzle and the second nozzle, the free end portion when the electric field is applied A piezoelectric valve 250 including a piezoelectric actuating member 230 for selectively closing the first nozzle or the second nozzle, and The first cylinder unit 110 is reciprocated by the working fluid controlled by the piezoelectric valve 250, and the first cylinder unit 110 and the piston rod 130 is integrated to cooperate with A piezoelectric valve modulator 200 including a dual type cylinder assembly 300 having a second cylinder part 320 filled with different kinds of fluids; And And a brake hydraulic circuit communicating with the second cylinder part 320 of the dual type cylinder assembly 300 and continuously controlling braking pressure by the piezoelectric valve modulator 200. (ABS). The method of claim 6, The first nozzle 223 is connected to the output side of the hydraulic pump 70 and one side of the piston 120 of the first cylinder unit 110, the second nozzle 224 is the output side of the hydraulic pump and the first An anti-lock brake system (ABS), which is connected to the other side of the piston of the cylinder part 110 and is provided with an orifice (243) (244) for a fixed pressure drop on each hydraulic pump side pipe. The method of claim 7, wherein The piezoelectric actuating member (230 ') is an anti-lock brake system (ABS), characterized in that consisting of a plate (227) having a predetermined length, and a piezoelectric ceramic plate (229) attached to the upper and lower portions of the plate. The method of claim 7, wherein The piezoelectric actuating member 230 "includes a rigid plate 237 having a predetermined length, and a piezoelectric ceramic laminated plate 239 mounted to upper and lower portions of the fixed end side of the rigid plate 237, respectively. The body (210) is an anti-lock brake system (ABS), characterized in that further comprising a pair of mutually opposing guide member (215) for guiding the stretching in the thickness direction of the piezoelectric ceramic laminated plate (239). The method according to claim 8 or 9, The solenoid valve 410 and the check valve 420 are provided in parallel, and include a mode selection valve assembly 400 mounted on a connection pipe of the brake hydraulic circuit connected to the dual type cylinder assembly 300. Anti-lock brake system (ABS) characterized in that. The method of claim 7, wherein The hydraulic pump is a piezoelectric hydraulic pump 70 for continuously supplying hydraulic pressure by operating the diaphragm 75 provided inside the body 72 by a vibrator 71 vibrating according to a signal applied from an electronic controller. Antilock brake system (ABS).