KR101118967B1 - Vehicle Brake Device for Electronic Hydraulic Brake System - Google Patents

Abstract

The present invention provides a braking device for an electrohydraulic brake system, comprising: an input shaft connected to a brake pedal; A pedal operation detecting device for detecting a driver's pedaling force; A pedal simulator provided in a control housing and connected to the input shaft to exert a pedal reaction force; A master cylinder for forming a braking pressure by the brake pedal and transmitting hydraulic pressure to a wheel brake side; A control piston provided adjacent to the first piston to transmit hydraulic pressure to the first piston in the master cylinder; A control chamber for controlling the pressure of the master cylinder between the control piston and the pedal simulator; And a hydraulic pressure supply device for transmitting hydraulic pressure corresponding to the driver's braking intention to the control chamber.

The pedal simulator includes: a pedal simulator piston slidable within the control housing; a pressure member retractable with movement of the input shaft within the pedal simulator piston; and a pedal simulator piston slidable in conjunction with movement of the pressure member. It has a simulator piston provided therein,

In the normal operation mode, the tip is accommodated at a predetermined interval from the inner groove formed in the control piston so that the force applied to the input shaft is not mechanically transmitted to the first piston, and the rear end passes through the pedal simulator piston and the simulator piston. In addition, by having a push rod that is inserted into the fixing groove formed in the pressure member, in the normal operation mode, the input element connected to the brake pedal and the piston of the master cylinder are mechanically separated from each other, in abnormal operation mode according to the driver's step Rapid braking pressure can be established.

Description

Braking System for Electro-Hydraulic Brake System {Vehicle Brake Device for Electronic Hydraulic Brake System}

The present invention relates to a braking device for an electro-hydraulic brake system. In particular, in the normal operation mode of the EHB system, the input element connected to the brake pedal and the piston of the master cylinder are mechanically separated from each other. A braking device for an electrohydraulic brake system for forming a braking pressure.

In general, the Electronic Hydraulic Brake System (EHB) detects the displacement of the brake pedal from the displacement sensor when the driver presses the brake pedal in normal operation mode and closes the shutoff valve to close the flow path between the master cylinder of the pedal simulator and the wheel. The pressure from the accumulator that stores the hydraulic pressure generated by the motor pump by calculating the wheel pressure in the ECU according to the pressure signal from the pressure sensor. Is controlled by independent feedback control.

At this time, the EHB system to elastically support the simulation piston 41 and the simulation piston 41 through the master cylinder 10 and the opening 13, as shown in FIG. A simulator 40 including a simulation spring 42 is included. In the conventional master cylinder 10 having the simulator 40 as described above, when the driver presses the brake pedal in the normal operation mode, the pressure is transmitted to the master cylinder 10 through the first piston 20, and the pressure thereof. Is transferred to the second piston 30 by the first spring 22 supporting the first piston 20, and at this time, the wheel cylinder (in the first chamber 21 and the second chamber 31 by the NO valve) Each of the flow paths (not shown) connected to each other is closed so that there is no place for the brake fluid to flow out, and the first piston 20 and the second piston 30 can no longer move forward. As the pressure on the pedal increases, the first piston 20 continues to compress while compressing the first spring 22, and the brake fluid of the first chamber 21 moves between the bore step 11 and the sealing element 36. It flows into the simulation chamber 43 through the flow path of the. At this time, the force by the simulation spring 42 forms a pressure in the simulation chamber 43 and the first chamber 21, and the driver feels a depression.

In addition, in the abnormal operation mode of the EHB system, since the shutoff valve is NO (Normally Open) state, the brake fluid of the first chamber 21 and the second chamber 31 of the master cylinder flows out to the wheel cylinder by the driver. As the brake fluid of the second chamber 31 flows into the wheel cylinder, the second piston 30 moves forward, and the stroke of the second piston 30 is greater than the interval between the passages 12 formed in the bore step 11. At the moment, the flow path between the first chamber 21 and the second chamber 31 is closed to operate in the same manner as the master cylinder applied to the conventional conventional brake, and the vehicle braking is performed by pressing the brake pedal. It is.

The braking device of the above-described hydraulic hydraulic brake system has a long stroke before the piston in the master cylinder is advanced by the driver's pedal input in the abnormal operation mode to block the fluid from entering the simulation piston. Due to the long time point at which pressure formation is initiated, there is a problem that rapid pressure formation is delayed.

Therefore, the present invention has been proposed to solve the above-mentioned conventional problems, and an object of the present invention is to mechanically separate the piston of the input cylinder and the master cylinder connected to the brake pedal from each other in the normal operation mode of the electronic hydraulic brake system. In an abnormal operation mode, a braking device of an electro-hydraulic brake system can be used to form a rapid braking pressure according to the driver's stepping force.

Braking apparatus of an electromagnetic hydraulic brake system according to an embodiment of the present invention to achieve the above object; An input shaft connected to the brake pedal; A pedal operation detecting device for detecting a driver's pedaling force; A pedal simulator provided in a control housing and connected to the input shaft to exert a pedal reaction force; A master cylinder for forming a braking pressure by the brake pedal and transmitting hydraulic pressure to a wheel brake side; A control piston provided adjacent to the first piston to transmit hydraulic pressure to the first piston in the master cylinder; A control chamber for controlling the pressure of the master cylinder between the control piston and the pedal simulator; And a hydraulic pressure supply device for transmitting hydraulic pressure corresponding to the driver's braking intention to the control chamber.

The pedal simulator includes: a pedal simulator piston slidable within the control housing; a pressure member retractable with movement of the input shaft within the pedal simulator piston; and a pedal simulator piston slidable in conjunction with movement of the pressure member. It has a simulator piston provided therein,

In the normal operation mode, the tip is accommodated at a predetermined interval from the inner groove formed in the control piston so that the force applied to the input shaft is not mechanically transmitted to the first piston, and the rear end passes through the pedal simulator piston and the simulator piston It is characterized in that it comprises a push rod that is inserted into the fixing groove formed in the pressure member.

The pedal simulator may further include a second simulator spring provided between the simulator piston and the pressure member to transfer the operation of the pressure member to the simulator piston, and the simulator piston between an inner wall of the simulator piston and the pedal simulator piston. And a first simulator spring elastically supported, wherein the spring constant of the first simulator spring is formed to be relatively smaller than the spring constant of the second simulator spring.

In the normal operation mode, the push rod connected to the control piston is mechanically separated from the first piston, and the pedal force is formed by the pedal simulator.

In addition, in the normal operation mode, the pedal simulator piston is moved in the direction of the input shaft by the pressure of the control chamber, characterized in that the movement is limited by the locking step provided in the control housing.

In addition, the pressure member and the push rod is characterized in that it is formed integrally.

In addition, in the abnormal operation mode, the push rod moves by a distance spaced from the control piston and then moves the control piston in the direction of the first piston, and the control piston is in mechanical contact with the first piston. It is characterized in that for transmitting the force applied to the input shaft.

As described above, the present invention mechanically separates the piston of the master cylinder and the input element connected to the brake pedal in the normal operation mode of the electronic hydraulic brake system, and in the abnormal operation mode to form a rapid braking pressure according to the driver's response It is effective.

Hereinafter, a preferred embodiment according to the technical spirit of the vehicle braking apparatus of the electronic hydraulic brake system of the present invention as described above will be described with reference to the accompanying drawings.

As shown in Figures 2 and 3, the braking device of the electrohydraulic brake system according to the present invention is the input shaft 310 connected to the brake pedal 300 that is operated by the driver during braking, in order to detect the driver's effort A pedal operation detecting device 500 including a pedal displacement sensor 510 or a stroke sensor 530, a pedal simulator 250 provided in the control housing 200 and connected to the input shaft 310 to exert pedal reaction force; The brake cylinder 300 is provided with a master cylinder 100 for transmitting hydraulic force to the wheel brakes 800a and 800b by forming a braking pressure, and a reservoir 120 provided on the master cylinder 100 to store oil. ) And a control piston 210 for transmitting hydraulic pressure to the first piston 110 in the master cylinder 100, and between the control piston 210 and the pedal simulator 250, the pressure of the master cylinder 100. To control Is provided between the control chamber 230, the hydraulic supply device 600 for transmitting the hydraulic pressure corresponding to the driver's braking intention to the control chamber 230, between the master cylinder 100 and the wheel brakes (800a, 800b) Various flow paths are formed therein and include an anti-lock brake system (ABS) hydraulic module 700 including a plurality of valves, pumps, accumulators, and the like.

The input shaft 310 connected to the brake pedal 300 is accommodated in the pressure member 260 provided to be movable in the axial direction in the pedal simulator piston 251. In addition, the brake pedal 300 is provided with a pedal displacement sensor 510 for detecting the driver's braking will.

One side of the pressure member 260 is provided with a receiving groove 261 for receiving the input shaft 310, the other side is formed with a fixed groove 263 is inserted into the rear end of the push rod 400 to be fixed pedal pedal 251 extends inside. In addition, the outer periphery of the pressure member 260 is formed with a protrusion 265 protruding in a radial direction, the stroke sensor 530 is provided on the pressure member 260.

In the pedal simulator piston 251, a simulator piston 253 slidable in the axial direction is provided with the movement of the pressure member 260. In addition, a second simulator spring 257 is provided between the simulator piston 253 and the pressure member 260 to transfer the operation of the pressure member 260 to the simulator piston 253, and the simulator piston 253 and the pedal simulator. A first simulator spring 255 is provided between the inner walls of the piston 251 to elastically support the simulator piston 253.

On the other hand, the first simulator spring 255 is provided with a smaller spring constant than the second simulator spring (257). This is because when the pressure member 260 is advanced by the input shaft 310 connected to the brake pedal 300, the first simulator spring 255 elastically supporting the simulator piston 253 is compressed toward the inner wall direction of the pedal simulator piston 251. While having a primary repulsion force in a direction opposite to the advancing direction of the input shaft 310, when the first simulator spring 255 is compressed to the maximum, the pressure member 260 pushes the second simulator spring 257 to the second simulator spring. 257 is compressed in the direction of the control piston 210 to have a secondary repulsive force so that the overall pedal feeling is to form a proper pedal feeling by the two linear repulsive force.

One end of the pedal simulator piston 251 is provided with a flange 258 protruding outward in the radial direction of the pedal simulator piston 251 to be limited to the rearward movement by the locking jaw 290 provided in the control housing 200, On the other end, the stop member 259 protruding inward in the radial direction is provided to prevent the pressure member 260 from being separated to the rear of the pedal simulator piston 251.

The master cylinder 100 includes a first piston 110 that transmits the pressure of the pedal stepped by the driver to the master cylinder, a second piston 130 that is advanced by the forward operation of the first piston 110, and the first piston. The first chamber 140 provided to compress the oil between the 110 and the second piston 130, and the first piston 110 is installed between the first piston 110 and the second piston 130. The first spring 170 for transmitting the operation of the second piston 130, the second chamber 141 for compressing the oil between the second piston 130 and the inner wall of the master cylinder, A second spring 171 is installed between the second piston 130 and the inner wall of the master cylinder to elastically support the second piston 130. In addition, the first and second ports 150 and 151 are provided at the lower portion of the master cylinder 100 to transfer the hydraulic pressure in the master cylinder 100 to the wheel brakes 800a and 800b. The inner diameter of the master cylinder 100 is larger than the diameter of the simulator piston 253.

An oil hole 270 is provided between the first piston 110 and the pedal simulator piston 251 in the control housing 200 to allow the braking hydraulic pressure stored in the accumulator 630 to flow in the normal operation mode.

The control piston 210 is provided at a portion adjacent to the first piston 110 to transfer the hydraulic pressure of the oil introduced through the oil hole 270 to the first piston 110. The control piston 210 is slidable in the axial direction in the control housing 200 and forms an inner groove 211 to accommodate the tip of the push rod 400 and is elastically supported by a support spring. In addition, the diameter of the control piston 210 is formed larger than the inner diameter of the master cylinder (100).

In the normal operation mode, the tip is spaced apart from the inner groove 211 of the control piston 210 so that the force applied to the input shaft 310 connected to the brake pedal 300 is not mechanically transmitted to the first piston 110. The push rod 400 is accommodated and inserted into and fixed to the fixing groove 263 formed at the pressure member 260 by penetrating the pedal simulator piston 251 and the simulator piston 253.

In addition, in the abnormal operation mode, the push rod 400 moves the control piston 210 in the direction of the first piston 110 after moving by the spaced apart from the control piston 210, such a control piston 210 Is mechanically in contact with the first piston 110 to transmit the force applied to the input shaft 310, thereby forming a brake pressure by the master cylinder 100 pressure. On the other hand, since the push rod 400 is not constrained from the pedal simulator piston 251 and the simulator piston 253, the push rod 400 is free to move.

A control chamber 230 is provided between the control piston 210 and the pedal simulator piston 251 to control the pressure of the master cylinder 100.

The hydraulic pressure supply device 600 for providing braking hydraulic pressure to the control chamber 230 includes a pump 620 operated by the motor 610. The motor 610 is controlled by an electronic control unit (ECU). That is, through the pedal operation detection and the signal activated by the stroke sensor 530 or the pedal displacement sensor 510, the pressure corresponding to the driver's braking intention according to the pedal stroke or pedal effort is applied to the motor 610 by the ECU. To control.

In addition, the hydraulic pressure supply device 600 includes an accumulator 630 provided between the outlet side of the pump 620 and the inlet valve 650 to temporarily store high pressure oil generated by the driving of the pump 620. At the outlet side of the accumulator 630, a pressure sensor 631 for measuring the oil pressure of the accumulator is provided. Accordingly, when the measured pressure is low by comparing the oil pressure measured by the pressure sensor 631 and the set pressure, the pump 620 is driven to charge the accumulator 630.

In order to prevent the accumulator 630 from filling up with excessive pressure, the hydraulic pressure supply device 600 is provided with a relief passage 640 connecting the outlet side of the accumulator 630 and the outlet side of the outlet valve 661 to be described later. A relief valve 641 is provided in the relief passage 640. The relief valve 641 maintains the normally closed state and opens when the oil pressure of the accumulator 630 exceeds the set pressure, thereby preventing excessive accumulation of the accumulator 630.

The inlet valve 650 is provided on the outlet side of the accumulator 630. The inlet valve 650 is normally closed to maintain the closed state, and is opened when the driver presses the brake pedal to control the braking oil stored in the accumulator 630. Forward to 230.

In addition, the hydraulic supply device 600 is provided with a return passage 660 connecting the control chamber 230 side and the inlet side of the pump 620, the oil of the control chamber 230 in the middle of the return passage 660 The outlet valve 661 which flows out to the inlet side of the pump 620 is provided.

The hydraulic pressure supply device 600 is connected to the control chamber 230 through the hydraulic line 670 connected to the oil hole 270 so that oil can flow in and out.

3 is a schematic view showing an ABS hydraulic module of the present invention, a plurality of solenoid valves (710a, 710b, 730a, 730b) for controlling the braking hydraulic pressure delivered to the wheel brakes (800a, 800b), and the wheel brake in the ABS decompression mode The low pressure accumulators 750a and 750b for temporarily storing the oil discharged from the 800a and 800b, the pump 770 for sucking and discharging the oil stored in the low pressure accumulators 750a and 750b, and the master cylinder 100. Oil suction passages 790a and 790b connecting the first and second ports 150 and 151 and the inlet side of each pump 770 are provided. The plurality of solenoid valves are divided into NO type solenoid valves 710a and 730a disposed upstream of each wheel brake 800a and 800b and NC type solenoid valves 710b and 730b disposed downstream. By controlling the speed of the vehicle, the solenoid valves 710a, 710b, 730a, and 730b are controlled to open and close according to the vehicle speed.

Next, the operation of the braking device of the hydraulic brake system according to the embodiment of the present invention will be described.

In the normal operation mode of the EHB system, referring to FIG. 2, when the driver presses the brake pedal 300, the input shaft 310 connected to the brake pedal 300 is advanced leftward in the axial direction and at the same time the pressure is applied to the brake pedal 300. The member 260 advances to the left in the pedal simulator piston 251. Movement of the pressure member 260 is detected by the stroke sensor 530, and the detected signal is sent to the ECU. The ECU accordingly drives a motor 610 for operating the pump 620 to generate braking hydraulic pressure. The high pressure oil produced by this pump 620 is stored in the accumulator 630. That is, the hydraulic pressure supply device 600 detects the driver's braking intention by the pedal displacement sensor 510 or the stroke sensor 530 and transmits it to the ECU, and the ECU stores the oil pressurized by the pump 620. In the accumulator 630, the hydraulic pressure corresponding to the driver's braking intention is opened to the control chamber 230 through the hydraulic line 670 by opening the inlet valve 650.

2, the braking hydraulic pressure introduced into the control chamber 230 acts on the control piston 210 on the left side and acts on the pedal simulator piston 251 on the right side. However, since the pedal simulator piston 251 is supported by the locking jaw 290 provided in the control housing 200, the movement to the right is limited. In addition, the control piston 210 is moved to the left side by the hydraulic pressure in the control chamber 230 and transmits the hydraulic pressure to the first piston 110 adjacent to the control piston 210, accordingly the first piston 110 ) Pushes the second piston 130 to the left, compresses the oil by the first and second chambers 140 and 141, and then the oil is introduced into the ABS hydraulic module by the first and second ports 150 and 151 so that the wheel brake 800a To 800b).

On the other hand, as the input shaft 310 advances to the left, the control piston 210 is driven by the hydraulic pressure introduced into the control chamber 230 while the push rod 400 is advanced to the free space S provided between the control pistons 210. ) Moves to the left to move the first piston 110 in the same direction as the push rod 400 moves forward. Therefore, in the normal operation mode, since the push rod 400 and the first piston 110 are not in mechanical contact, the force transmitted to the pressure member 260 and the push rod 400 through the input shaft 310 is the first. It is not delivered to the piston 110.

In addition, the pedal simulator piston 251 is restricted to move to the right by the locking jaw 290 due to the hydraulic pressure introduced into the control chamber 230, and the brake pedal 300 when the driver steps on the brake pedal 300. When the pressure member 260 advances by the input shaft 310 connected to the second shaft spring 257 that elastically supports the simulator piston 253, it is compressed in the direction of the simulator piston 253 to advance the input shaft 310. It has a first repulsive force in the direction opposite to the direction, and when the second simulator spring 257 is compressed as much as possible, the simulator piston 253 pushes the first simulator spring 255, the second simulator spring 257 is a pressure member ( 260) has a secondary repulsion force in the forward direction of compression to form a proper pedal feeling by the overall pedal feeling of the two linear repulsive force. Therefore, a normal pedal feeling is given to a driver.

In the abnormal operation mode of the EHB system, the braking hydraulic pressure to the control chamber 230 does not flow, but the input shaft 310 and the pressure member 260 move forward to the left with the operation of the brake pedal 300. The first simulator spring 255 is compressed in the forward direction. After the first simulator spring 255 is compressed to the maximum and close to the pedal simulator piston 251, the second simulator spring 257 is compressed. Accordingly, the pedal simulator piston 251 pressurizes the control chamber 230. At the same time it is in close contact with the control piston (210). In addition, the push rod 400 inserted and fixed in the fixing groove 263 of the pressure member 260 also moves by the clearance S, and then contacts the control piston 210 to advance the control piston 210. . Accordingly, the push rod 400 is connected to the input shaft 310 and the first piston 110.

Accordingly, since the first piston 110 advances to the left to advance the second piston 130, the oil in the first and second chambers 140 and 141 is compressed to compress the oil by the first and second ports 150 and 151. Oil flows into the module and is delivered to the wheel brakes 800a and 800b. Therefore, rapid formation of the brake pressure is possible.

In the above, the present invention has been illustrated and described with respect to certain preferred embodiments. However, the present invention is not limited only to the above-described embodiments, and those skilled in the art to which the present invention pertains can variously change without departing from the gist of the technical idea of the present invention described in the claims below. Could be done.

1 is a cross-sectional view showing a master cylinder having a conventional pedal simulator.

2 is a cross-sectional view showing a braking device and a hydraulic pressure supply device of the electromagnetic hydraulic brake system according to the present invention.

3 is a cross-sectional view showing a braking device and an ABS hydraulic module of the electromagnetic hydraulic brake system according to the present invention.

* Description of the symbols for the main parts of the drawings *

100: master cylinder 110: first piston

200: control housing 210: control piston

230: control chamber 250: pedal simulator

251: pedal simulator piston 260: pressure member

253: simulator piston 255: first simulator spring

257: second simulator spring 263: fixed groove

300: brake pedal 310: input shaft

400: push rod 500: pedal operation detection device

600: Hydraulic supply device 700: ABS hydraulic module

800a, 800b: Wheel brake

Claims (6)

An input shaft connected to the brake pedal; A pedal operation detecting device for detecting a driver's pedaling force; A pedal simulator provided in a control housing and connected to the input shaft to exert a pedal reaction force; A master cylinder for forming a braking pressure by the brake pedal and transmitting hydraulic pressure to a wheel brake side; A control piston provided adjacent to the first piston to transmit hydraulic pressure to the first piston in the master cylinder; A control chamber for controlling the pressure of the master cylinder between the control piston and the pedal simulator; And a hydraulic pressure supply device for transmitting hydraulic pressure corresponding to the driver's braking intention to the control chamber. The pedal simulator includes: a pedal simulator piston slidable within the control housing; a pressure member retractable with movement of the input shaft within the pedal simulator piston; and a pedal simulator piston slidable in conjunction with movement of the pressure member. It has a simulator piston provided therein, In the normal operation mode, the tip is accommodated at a predetermined interval from the inner groove formed in the control piston so that the force applied to the input shaft is not mechanically transmitted to the first piston, and the rear end passes through the pedal simulator piston and the simulator piston Braking device of the electromagnetic hydraulic brake system, characterized in that it comprises a push rod that is inserted into the fixed groove formed in the pressure member. The method of claim 1, The pedal simulator elastically supports the simulator piston between the simulator piston and the inner wall of the pedal simulator piston and a second simulator spring provided between the simulator piston and the pressure member to transfer the operation of the pressure member to the simulator piston. And a first simulator spring, wherein the spring constant of the first simulator spring is formed to be smaller than the spring constant of the second simulator spring. The method of claim 1, In the normal operation mode, the push rod connected to the control piston is mechanically separated from the first piston to operate, the braking device of the electro-hydraulic brake system, characterized in that the pedal force is formed by the pedal simulator. The method of claim 1, In the normal operation mode, the pedal simulator piston is moved in the direction of the input shaft by the pressure of the control chamber, and the braking device of the electromagnetic hydraulic brake system, characterized in that the movement is limited by the locking jaw provided in the control housing. . The method of claim 1, The pressure member and the push rod is a braking device of an electro-hydraulic brake system, characterized in that formed integrally. The method according to any one of claims 1 to 5, In the abnormal operation mode, the push rod is moved by a distance spaced from the control piston, and then the control piston is moved in the direction of the first piston, and the control piston is in mechanical contact with the first piston so that the input shaft Braking device of an electro-hydraulic brake system, characterized in that for transmitting a force applied to.

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