KR20200072602A - Electric brake booster with pressure balancing structure - Google Patents

Abstract

According to the present invention, an electric brake booster using a pressure balancing structure forms braking power by a resultant force of a drive force of a motor and a pedal force of a brake pedal in accordance with a brake pedal operation of a driver, and comprises: a first pressure device in which brake fluid pressure is created by a pedal force of a brake pedal in accordance with a brake pedal operation of a driver; a second pressure device in which the same pressure as the first pressure device is formed, and a drive force of a motor is formed in accordance with an operation of the motor connected to one side thereof; a master chamber to receive a resultant force of the drive force of the motor and the pedal force of the brake pedal from a master piston reciprocating in the second pressure device; and a pressure balancing device to maintain the pressure of the first pressure device acting on one side thereof and the pressure of the master chamber acting on the other side thereof at a prescribed ratio through a reaction spring mounted on one side and the other side thereof. A prescribed ratio of the drive force of the motor and the pedal force of the brake pedal is maintained by the pressure balancing device. According to the present invention, a fault probability is reduced and costs are reduced by a simplified flow path. In addition, the present invention can reduce the size of a booster by using a fixed sensor, thereby improving layout configuration and collision performance.

Description

ELECTRIC BRAKE BOOSTER WITH PRESSURE BALANCING STRUCTURE

The present invention relates to an electric brake booster for a vehicle, in particular, to provide an electric brake booster that uniformly forms the ratio of the pedal pedal effort and the driving force of the motor and improves the braking feeling when the motor is not operating or delays operation. It's about the brake booster.

In general, most vehicles are equipped with a power-assisted braking system, i.e., a power brake, so that the driver can decelerate or stop the vehicle even if the driver presses the pedal with relatively little force.

This is possible because the vehicle is provided with a vacuum brake booster or a hydraulic brake booster in the brake device as well as a hydraulic power transmission mechanism, thereby providing braking auxiliary power by the booster.

In this regard, the conventional Korean Patent Registration No. 10-0947379 (braking safety device for vacuum brake booster) relates to a braking safety device for vacuum brake booster, which causes a failure of the vacuum pump that supplies compressed air to the vacuum brake booster. However, a braking safety device for a vacuum brake booster that enables the operation of the vacuum brake booster is disclosed.

However, the conventional vacuum brake booster has a problem in that a separate electronic or mechanical vacuum pump must be additionally applied when the engine has insufficient vacuum.

In addition, the conventional vacuum brake booster has a problem in that active braking is impossible while the driver is not braking.

In this regard, Korean Patent Publication No. 10-2015-0022439 (electric braking system and control method thereof) initializes the mechanical origin position of the piston provided in the electric booster braking system to achieve uniform and stable control. Disclosed is an electric booster braking system and a control method thereof.

However, the conventional electric hydraulic booster does not include a structure for buffering the reaction force transmitted to the driver's brake pedal when the motor breaks down or the operation of the motor is delayed, thereby causing inconvenience to the driver's braking.

In addition, in the conventional electric hydraulic booster, the master cylinder receiving pressure through the operation of the motor and the sub-master cylinder and the pressure through the operation of the brake pedal of the driver and the master cylinder are formed in a straight line.

Therefore, there is a problem in that the limitation on the mounting position of the bar where the booster must be installed close to the brake pedal and securing the clearance in the peripheral part are disadvantageous.

Korean Registered Patent No. 10-0947379 Korean Patent Publication No. 10-2015-0022439

The present invention, in the conventional brake booster, by applying a pressure balancing structure to maintain a constant ratio of the torque and the driving force of the motor according to the driver's brake pedal operation during normal operation of the motor, and when the motor is not operating or the motor's effort It is an object of the present invention to provide an electric brake booster that improves the driver's braking feeling when the auxiliary threshold is reached.

In order to achieve the above object, the present invention, in the electric brake booster is applied to the pressure balancing structure to form a braking force by the combined force of the driving force of the motor and the pedal force of the brake pedal according to the driver's brake pedal operation, the brake pedal operation of the driver A first pressure device for generating brake fluid pressure therein by the effort of the brake pedal according to; A second pressure device in which the same pressure as the first pressure device is formed inside and a driving force of the motor is formed according to the operation of the motor connected to one side; A master chamber receiving a combined force of a pedal pedal effort and a driving force of the motor from the master piston reciprocating inside the second pressure device; And a pressure balancing device that maintains the pressure of the first pressure device acting on one side and the pressure of the master chamber acting on the other side at a predetermined ratio through reaction springs mounted on one side and the other side.

Provided is an electric brake booster to which a pressure balancing structure is applied, wherein a predetermined ratio of the pedal pedal effort and the driving force of the motor is maintained by the pressure balancing device.

Preferably, the first pressure device includes: a pedal chamber in which brake hydraulic pressure is generated inside by a pedal effort of the brake pedal; A push rod that linearly moves in the pedal chamber according to the operation of the brake pedal; And one end is coupled to the push rod and the return spring is connected to the other end of the pedal rod according to the linear movement of the pedal piston reciprocating motion inside; may further include.

Preferably, the pedal chamber may be connected to the pedal chamber supply flow path receiving the brake fluid from the oil reservoir on the upper portion.

Preferably, the second pressure device may be connected to the first pressure device through a pedal chamber flow path.

Preferably, the second pressure device may be integrally formed with the first pressure device.

Preferably, the second pressure device includes: a boosting chamber having the same brake fluid pressure as the first pressure device and having a motor coupled to one side; It may further include.

Preferably, the second pressure device, the screw coupled to the motor to rotate in the interior of the second pressure device according to the operation of the motor; And a nut coupled to the screw and linearly moving according to the rotational motion of the screw to transmit the driving force of the motor to the master chamber.

Preferably, the master piston has one side in contact with the nut and the other side is connected to a return spring connected to one end of the master chamber to reciprocate the inside of the second pressure device according to the linear motion of the nut, and the pedal pedal and the motor of the brake pedal to the master chamber It can transmit the sum of the driving force of the.

Preferably, a pedal sensor for measuring the displacement of the brake pedal; and a pedal sensor may measure any one of a brake pedal, a push rod, or a pedal piston.

Preferably, the motor is equipped with a sensor for measuring the rotation angle and the amount of rotation of the motor can be determined according to the displacement of the brake pedal.

Preferably, the master chamber may be connected to the caliper of the ESC module or brake through the master chamber flow path formed in the master chamber.

Preferably, the pressure balancing device can be operated under conditions in which pressure is generated inside the first pressure device and pressure is generated in the master chamber.

Preferably, the pressure balancing device includes: a first balancing chamber in which the same pressure as the master chamber is formed; A second balancing chamber having the same pressure as the first pressure device; A center chamber positioned between the first balancing chamber and the second balancing chamber and forming a closed space; And a balancing piston on which one side on which the first reaction spring is mounted contacts the first balancing chamber and the other side on which the second reaction spring is mounted contacts the second balancing chamber.

Preferably, in the balancing piston, when the ratio of the pressure of the first pressure device and the pressure of the master chamber is different from a predetermined ratio, the pressure of the first pressure device and the master chamber as the first reaction spring is compressed and the second reaction spring is tensioned This can be maintained at a predetermined rate.

Preferably, the first balancing chamber and the master chamber may be connected, and the second balancing chamber and the first pressure device may be connected.

Preferably, the first balancing chamber and the master chamber may be connected, and the second balancing chamber and the second pressure device may be connected.

Preferably, the balancing piston may have a surface area on one side contacting the second balancing chamber larger than a surface area on the other side contacting the first balancing chamber.

Preferably, In the center chamber, a flow path connected to the oil reservoir is formed so that the brake fluid is filled therein.

Preferably, in the center chamber, a passage through which air is introduced may be formed so that air is filled therein.

According to the present invention having the configuration as described above, there is an advantage that the cost is reduced and the probability of failure is reduced by the simplified flow path configuration.

In addition, the present invention has the advantage that the redundancy of the actuator is secured when the booster fails by using the ESC as an auxiliary actuator.

In addition, the present invention, by applying a fixed sensor can reduce the size of the booster, accordingly there is an advantage in layout configuration and collision performance.

In addition, according to the present invention, as the pedal chamber and the boosting chamber are separately configured through a flow path, the degree of freedom in design is increased and the clearance between peripheral parts is advantageous.

In addition, the present invention has the advantage of improving stability in the booster operation by maintaining a predetermined ratio of the pedal pedal effort and the driving force of the motor during normal operation of the motor by applying the pressure balancing structure.

In addition, the present invention has an advantage in that the response of the motor is delayed due to the application of the pressure balancing structure, the non-operation, and the heterogeneity of the pedal is alleviated when the limit of motor assistance is reached.

Figure 1 shows the operation of the conventional electric booster.
Figure 2 shows a schematic diagram of an electric brake to which the pressure balancing structure of the present invention is applied.
3 shows a state of the electric brake booster to which the pressure balancing structure of the present invention is applied.
4(a) shows the pressure applied to the master piston of the present invention when the driver operates the brake pedal.
Figure 4 (b) shows the pressure applied to the master piston of the present invention during operation of the motor.
4(c) shows the pressure applied to the master piston of the present invention due to the operation of the brake pedal of the driver and the operation of the motor.
Figure 5 (a) shows the initial position of the pedal piston of the present invention
5(b) shows the initial position where the pedal piston of the present invention generates hydraulic pressure in the pedal chamber.
Figure 6 shows the mounting position of the pressure balancing device according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the contents described in the accompanying drawings. However, the present invention is not limited or limited by the exemplary embodiments. The same reference numerals in each drawing denote members that perform substantially the same function.

Figure 1 shows the operation of the conventional electric booster.

Referring to Figure 1, the conventional electric booster is modified according to the balance of the force of the pedal rod (1), the boosting body (2) and the pedal rod (1) for transmitting the pedal effort by the driver's brake pedal operation It consists of a rubber reaction disk (3), a booster rod (4) for transmitting the output of the booster to the piston (6), and a chamber (5) forming a cylinder (7).

The conventional electric booster includes a reaction disk 3 that is deformed according to the balance of force as described above, and thus, a displacement measuring sensor for measuring and comparing the displacement of the boosting body 2 and the relative displacement of the pedal ( 8) is used.

In addition, since the pedal force according to the driver's brake pedal operation must be transmitted to the booster without intervention of the brake fluid, the conventional booster is installed close to the rear surface of the pedal.

Figure 2 shows a schematic diagram of an electric brake to which the pressure balancing structure of the present invention is applied.

Referring to FIG. 2, the electric brake booster to which the pressure balancing structure of the present invention is applied is a device that forms a braking force by the combined force of the pedal pedal force and the driving force of the motor 500 according to the driver's brake pedal operation, and the first pressure It may include a device 10, a second pressure device 20, a master chamber 300 and a pressure balancing device 40.

The first pressure device 10 may generate a brake fluid pressure therein by the braking force of the brake pedal according to the driver's operation of the brake pedal.

In the second pressure device 20, the same pressure as the first pressure device 10 is formed therein, and a driving force of the motor 500 may be formed according to the operation of the motor 500 connected to one side.

The second pressure device 20 may be connected to the first pressure device 10 and the pedal chamber 100 through a flow path to form the same pressure as the first pressure device 10, and also, the first pressure device 10 ) May be formed integrally with the same pressure as the first pressure device 10.

The master chamber 300 may receive the combined force of the braking force of the brake pedal and the driving force of the motor 500 from the master piston 301 reciprocating inside the second pressure device 20.

The pressure balancing device 40 can maintain the pressure of the first pressure device 10 acting on one side and the pressure of the master chamber 300 acting on the other side at a predetermined ratio through the reaction force springs mounted on one side and the other side. In addition, a predetermined ratio of the pedal pedal effort and the driving force of the motor 500 may be maintained by the pressure balancing device 40. This is described in detail below.

The pressure balancing device 40 maintains a predetermined ratio of the pressure of the first pressure device 10 and the pressure of the master chamber 300. As the pressure is generated inside the first pressure device 10, the master chamber It can be operated under the condition that pressure is generated in 300.

3 shows a state of the electric brake booster to which the pressure balancing structure of the present invention is applied.

Referring to FIG. 3, the first pressure device 10 may include a pedal chamber 100, a push rod 101 and a pedal piston 103.

The pedal chamber 100 receives the brake fluid through the pedal chamber supply passage 120 connected to the oil reservoir 600, and the pedal piston 103 according to the operation of the brake pedal inside the cylinder surrounding the pedal chamber 100 ) Can generate brake fluid pressure by reciprocating motion.

The push rod 101 may move back and forth in a straight line inside the pedal chamber 100 according to the operation of the brake pedal of the driver.

The pedal piston 103 has one end coupled with the push rod 101 to reciprocate inside the pedal chamber 100 according to the forward/backward movement of the push rod 101, and the return spring 105 is connected to the other end to return to the original position. Can.

At this time, the pedal piston 103 reciprocates inside the pedal chamber 100 with a predetermined gap between the chamber surrounding the pedal chamber 100.

The gap between the pedal piston 103 and the chamber surrounding the pedal chamber 100 is provided with a sealing 107 on the upper portion of the pedal chamber 100 to prevent leakage of brake fluid and to form pressure inside the pedal chamber 100.

When the flow path hole 102 is formed in the lower portion of the pedal piston 103 so that the flow path hole 102 communicates with the pedal chamber supply flow path 120 between the sealing 107, the pedal chamber 100 in the oil reservoir 600 The brake fluid is supplied.

The second pressure device 20 may include a boosting chamber 200.

The boosting chamber 200, the same brake fluid pressure as the first pressure device 10 is formed inside the cylinder surrounding the boosting chamber 200, the motor 500 may be coupled to one side.

The boosting chamber may be connected to the pedal chamber 100 and the pedal chamber flow path 110 to receive the brake fluid pressure of the pedal chamber 100 so that the same brake fluid pressure as the first pressure device 10 is formed.

In addition, since the internal pressures of the boosting chamber 200 and the pedal chamber 100 need only be formed the same, the boosting chamber 200 and the pedal chamber 100 may be formed integrally.

The boosting chamber 200 may be configured to receive the brake pressure indirectly through the brake fluid pressure formed in the pedal chamber 100 through the pedal chamber flow path 110, or may be integrally formed with the pedal chamber, and the pedal chamber 100 And boosting chamber 200 are not limited to the mounting position.

Therefore, the electric brake booster of the present invention can freely configure the entire layout of the booster including the pedal chamber 100, the master chamber 300, or the motor 500.

The second pressure device 20 of the present invention may further include a screw 201, a nut 205 and a master piston 301 therein.

The screw 201 is coupled to the motor 500 connected to the second pressure device 20 to rotate in the interior of the second pressure device 20 according to the operation of the motor 500.

The screw 201 is combined with the motor 500 to rotate in the interior of the boosting chamber 200 according to the operation of the motor 500, and the nut 205 is screwed to surround the circumferential surface of the screw 201 ( 201) can be linearly moved inside the boosting chamber 200 according to the rotational movement of the screw 201.

At this time, the screw 201 prevents the screw 201 from being disengaged from the nut 205 according to the linear motion of the nut 205, and at the same time, the screw 201 is combined with the cylindrical nut 205, thereby boosting the inside of the boosting chamber 200 In order to rotate in the vicinity coupled to the motor 500 may be formed in a T shape.

Between the screw 201 and the chamber surrounding the boosting chamber 200, a bearing 203 may be further included to assist rotation of the screw 201 and at the same time to reduce friction.

The chamber surrounding the boosting chamber 200 is formed with a hole of a predetermined width for the coupling of the motor 500 and the screw 201, and the screw 201 is inserted into the hole formed in the chamber surrounding the screw 201 and the boosting chamber 200. ) And a sealing 207 that fills the gap between the chambers surrounding the boosting chamber 200 is provided to prevent leakage of the brake fluid and form a pressure inside the boosting chamber 200.

The nut 205 may transmit the driving force of the motor 500 to the master chamber 300 through the master piston 301 whose one side contacts the nut 205 according to the linear motion.

One side of the master piston 301 is in contact with the nut 205. Therefore, as the screw 201 rotates according to the rotation of the motor 500 and the nut 205 advances, the nut 205 may advance together by a pushing force.

That is, the master piston 301 has one side in contact with the nut 205, the other side is connected to the return spring 303 connected to one end of the master chamber 300, and the second pressure device according to the linear motion of the nut 205 ( 20) the inside of the reciprocating motion may transmit the combined force of the driving force of the motor 500 connected to the boosting chamber 200 and the pedal pedal braking force to the master chamber 300.

The master chamber 300 receives the brake fluid from the oil reservoir 600 through the supply path 320 of the master chamber 300 connected to the oil reservoir 600, and the reciprocating motion of the master piston 301 and the nut ( The pressure is generated inside by the combined force of the driving force of the motor 500 transmitted from 205.

Therefore, the pressure formed in the master chamber 300 is the value obtained by dividing the driving force of the motor 500 by the brake fluid pressure of the boosting chamber 200 by the area AA where the brake fluid in the master piston 301 and the boosting chamber 200 abuts. It becomes the value added.

The master chamber 300 and the boosting chamber 200 include a chamber and a master chamber 300 surrounding the master chamber 300 and the boosting chamber 200 on both sides of the supply path 320 of the master chamber 300 connected to the oil reservoir 600 ( 300) and the sealing 209 filling the gap between the boosting chamber 200 may have different pressures.

In addition, the master chamber 300 and the boosting chamber 200 may be made of separate cylinders, and the sum of the pressure formed in the boosting chamber 200 and the driving force of the motor 500 may be transmitted to the master chamber 300. It can be configured in any form possible.

The master chamber 300 may be connected to the caliper of the ESC module or brake through the master chamber flow path 310 formed under the master chamber 300.

That is, the master chamber 300 may transmit the combined force of the driving force of the motor 500 and the pedal effort according to the driver's brake pedal operation transmitted from the pedal chamber 100 to the ESC module or the caliper of the brake.

The electric crave booster to which the pressure balancing structure of the present invention is applied is controlled by an ECU, and the master chamber 300 may be connected to an ESC module including an ECU controlling the motor 500. The ESC module can again be connected to the caliper of the brake.

If an abnormality occurs in the booster, such as when a defect occurs in the motor 500, braking may be performed by an ESC module acting as an auxiliary actuator.

The electric brake booster to which the pressure balancing structure of the present invention is applied may further include a pedal sensor for measuring the displacement of the brake pedal.

The pedal sensor may directly or indirectly measure the displacement of any one of the brake pedal, push rod 101, or pedal piston 103.

A sensor for measuring the rotation angle is built in the motor 500, and the rotation amount of the motor 500 can be determined according to the displacement of the brake pedal.

This calculates the volume change amount of the pedal chamber 100 through the absolute displacement of the brake pedal or the like measured by the pedal sensor, and generates the volume change amount of the master chamber 300 as much as the volume change amount of the pedal chamber 100 It is possible to control the moving distance of the nut 205 so as to control the back power ratio according to the driver's brake pedal operation and the pressure according to the driving force of the motor 500.

At this time, the moving distance of the nut 205 may be calculated based on the rotation angle of the motor 500 measured by the motor 500 sensor mounted on the motor 500, and as a result, the motor ( The rotation amount of 500) may be determined according to the displacement of the brake pedal.

4(a) shows the pressure applied to the master piston 301 of the present invention when the driver operates the brake pedal, and FIG. 4(b) shows the master piston 301 of the present invention when the motor 500 is operated. 4(c) shows the pressure applied to the master piston 301 of the present invention due to the operation of the brake pedal and the operation of the motor 500 by the driver.

4 (a) to (c), the master piston 301 has a clamping force of the nut 205 due to the driving force of the motor 500 in a portion corresponding to the contact area with the nut 205 Is delivered.

At the same time, the master piston 301 is transmitted to the area of the brake fluid inside the boosting chamber 200 and the master piston 301 in contact with the driver AA by operating the brake pedal.

That is, in the master piston 301, the driving force of the motor 500 is divided by the cross section of the contact area between the nut 205 and the master piston 301, and the pressure of the pedal chamber 100 (the pressure of the boosting chamber 200) And the same), respectively, and this pressure is transmitted to the master chamber 300.

Therefore, as shown in Figure 4 (c), the output of the booster transmitted to the ESC module or the caliper of the brake, the pressure of the pedal chamber 100 and the brake fluid and the master piston 301 inside the boosting chamber 200 It becomes the force which multiplied this contact area AA and the clamping force of the nut 205.

Referring to FIG. 3, the pressure balancing device 40 may further include a first balancing chamber 400, a second balancing chamber 430, a center chamber 420 and a balancing piston 403.

The first balancing chamber 400 may have the same pressure as the master chamber 300, and the second balancing chamber 430 may have the same pressure as the first pressure device 10.

The first balancing chamber 400 is formed with the same pressure as the master chamber 300, and the second balancing chamber 430 is formed with the same pressure as the first pressure device 10, as shown in FIG. , The first balancing chamber 400 and the master chamber 300 may be connected, and the second balancing chamber 430 and the first pressure device 10 may be connected.

In addition, as illustrated in FIG. 3, the first balancing chamber 400 and the master chamber 300 are connected through the balancing chamber flow path 410 and the master chamber flow path 310 and the second balancing chamber 430 is the first The second pressure device 20 having the same pressure as the balancing chamber 400 may be connected through the boosting chamber flow path 210.

The center chamber 420 is positioned between the first balancing chamber 400 and the second balancing chamber 430 and may form a closed space.

The center chamber 420 may be configured such that a flow path connected to the oil reservoir 600 is formed to fill the brake fluid therein, or a passage through which air is introduced to fill the air.

In the balancing piston 403, one side on which the first reaction force spring is mounted may contact the first balancing chamber 400 and the other side on which the second reaction force spring is mounted may contact the second balancing chamber 430.

The balancing piston 403 is equipped with a cylinder surrounding the balancing piston 403 and a sealing 407 therebetween to prevent leakage, while simultaneously forming pressure in the first balancing chamber 400 and the second balancing chamber 430. You can make it possible.

In the balancing piston 403, when the ratio of the pressure of the first pressure device 10 and the pressure of the master chamber 300 is different from a predetermined ratio, the first pressure is compressed and the first pressure is applied as the second reaction spring is tensioned. The pressure of the device 10 and the master chamber 300 is maintained at a predetermined ratio.

On the other hand, when the pressure of the pedal chamber 100 increases, the balancing piston 403 can move downward as the second reaction spring 405 is tensioned and the first reaction spring 401 is compressed, and the pedal chamber ( When the pressure of 100) is relatively reduced, the balancing piston 403 may also return to its position as the first reaction spring 401 and the second reaction spring 405 are returned to their original state.

The material of the first reaction force spring 401 and the second reaction force spring 405 may be formed of a single rubber or spring, or a combination thereof.

When the balancing piston 403 moves downward, the closed space of the center chamber 420 may generate an air spring effect by generating a reaction force by compressed air, which includes the first reaction force spring 401 and the second reaction force spring ( 405).

The balancing piston 403 has a surface area (A1) on one side that contacts the second balancing chamber 430 so that the pressure balancing device 40 can maintain a predetermined ratio of the pedal pedal effort and the driving force of the motor 500. 1 It may be formed wider than the surface area (A2) of the other side in contact with the balancing chamber 400.

The pressure balancing device 40 allows the motor 500 to maintain a predetermined ratio of the pedal pedal effort and the driving force of the motor 500 when the motor 500 operates normally.

As the driver presses the brake pedal, the push rod 101 and the pedal piston 103 are pressed to increase the pressure (hereinafter, P1) in the pedal chamber 100. In addition, the pedal piston displacement and the nut 205 displacement comparison control is performed, and the master piston 301 moves to the left according to the clamping force of the nut 205 according to the driving of the motor 500, and the inside of the master chamber 300 is moved. The pressure (hereinafter, P2) increases.

At this time, the balancing piston 403 serves to balance the pressure so that P2*A2 = P1*A1, and the ratio of the back pressure according to the driver's brake pedal pressure and the driving force of the driving force of the motor 500 can be obtained as follows. .

Power ratio = master piston output / pedal piston output

= (P2*Am)/(P1*Ap)

= (A1/A2)*(Am/Ap)

(A1; the area where the upper surface of the balancing piston 403 and the brake fluid received from the boosting chamber 200 abut, A2; the area where the lower surface of the balancing piston 403 and the brake fluid in the balancing chamber 400 abut, Ap; pedal The area where the piston 103 comes into contact with the brake fluid in the pedal chamber 100, Am; the contact area between the nut 205 and the master piston 301)

Here, A1, A2, Am and Ap are all constants, so the power ratio can be kept constant.

In addition, the pressure balancing device 40, in the event of an emergency in which the motor 500 does not operate normally, enables the braking of the vehicle with only the effort of the brake pedal and at the same time may serve to improve the braking feeling.

When the pressure balancing device 40 is not included, the push rod 101 and the pedal piston 103 are pressed as the driver presses the brake pedal, and the return spring 105 is compressed accordingly. At this time, even if the control is performed by comparing the displacement of the pedal piston 103 and the displacement of the nut 205, if the response of the motor 500 is delayed or the motor 500 is not operated, the master piston 301 has a pedal chamber. Only the pressure generated at 100 is transmitted.

Accordingly, a separation occurs between the nut 205 without movement and the master piston 301 receiving pressure generated from the pedal chamber 100, and the pressure inside the pedal chamber 100 increases rapidly. As the pressure inside the pedal chamber 100 increases rapidly, a time delay occurs in the booster to reach a target value of a predetermined effort.

In addition, at this time, when the driver attempts to operate the brake pedal, there is a problem that the brake pedal operation is not easy due to an increase in the pressure in the pedal chamber 100.

On the other hand, when the pressure balancing device 40 is included, when the response of the motor 500 is delayed or the motor 500 is broken, the pressure of the pedal piston 103 is temporarily increased by the operation of the brake pedal. The pressure rise inside the pedal chamber 100 is alleviated as the balancing piston 403 moves downward.

As the pressure rise inside the pedal chamber 100 is alleviated, a sudden pressure change phenomenon of the pedal chamber 100 is reduced when the driver tries to operate the brake pedal, thereby improving the braking feeling.

When the motor 500 is operated again, the balancing piston 403 goes back to the original position, the pressure inside the pedal chamber 100 decreases, and the booster can reach a desired braking force.

The pressure balancing device 40 may function to improve the feeling of braking at the knee point where the motor 500 operates normally but has reached the limit of its force.

When the pressure balancing device 40 is not included at the knee point, when the force of the motor 500 reaches the threshold, the driving force of the motor 500 is kept constant and the braking force is increased according to the increase in the pedal force due to the driver's brake pedal operation Will increase.

At this time, the separation between the nut 205 without motion and the master piston 301 receiving the pressure generated from the pedal chamber 100 occurs, and the pressure inside the pedal chamber 100 increases rapidly.

On the other hand, when the pressure balancing device 40 is included, since the driving force of the motor 500 is applied to the master chamber 300 before reaching the knee point, it appears as ΔP3/ΔP1> 1, but the braking force continues to rise and the motor ( At the knee point where the force limit point of 500) is reached, the force of the motor 500 is kept constant and P1 continues to increase.

As the P1 continuously rises, the balancing piston moves downward and the reaction spring 401 on the lower surface of the balancing piston 403 is compressed to the maximum, so that ΔP3/ΔP1 approaches 1, and finally ΔP3/ΔP1 = 1 .

Therefore, even if the response of the motor 500 is delayed or the force of the motor 500 reaches the limit as in the case where the motor 500 has failed, the balancing piston 403 moves downward and the pressure inside the pedal chamber 100 The rise can be alleviated.

The pressure balancing device 40 has the same role as described above as long as one side is connected to the pedaling chamber 100 having the same pressure as the boosting chamber 200 or the boosting chamber 200 and the other side is connected to the master chamber 300. Wherever possible, the mounting position may not be limited.

The pressure balancing device 40 may be operated only under the condition that pressure is generated in the boosting chamber 200 and pressure is generated in the master chamber 300 due to its role.

Accordingly, when the ESC or ADAS function is implemented or only the motor 500 is operated due to a stroke, etc. in the invalid section of the pedal chamber 100, so that no pressure is generated in the boosting chamber 200, the pressure balancing device 40 Does not work.

The invalid section of the pedal chamber 100 may be described through FIG. 5. 5(a) shows the initial position of the pedal piston 103 of the present invention, and FIG. 5(b) shows the initial position where the pedal piston 103 of the present invention generates hydraulic pressure in the pedal chamber 100. Shows.

Before the driver presses the brake pedal, the pedal piston 103 is located in a position where the position of the flow path hole 102 through which the brake fluid flows through the pedal chamber supply passage 120 does not exceed the uppermost portion of the sealing 107. .

Thereafter, when the driver presses the brake pedal, the pedal piston 103 moves downward, and the oil pressure in the pedal chamber 100 passes through the lowermost portion of the sealing 107 and the oil hole 102 passes through the lower portion of the oil reservoir (600). ) Can be formed from when the brake fluid cannot be supplied.

Accordingly, even if the pedal piston 103 moves between the sections of FIGS. 5A and 5B, an invalid section in which hydraulic pressure does not occur exists in the pedal chamber 100. Within this invalidity section, the pressure balancing device 40 will not operate.

On the other hand, the electric brake booster of the present invention, may be configured to vary the pressure of the front and rear wheels according to the configuration of the operating circuit, or may be installed to act as a modulator for varying the pressure of each of the four wheels. .

The objects and effects of the present invention may be naturally understood or more apparent by the following description, and the objects and effects of the present invention are not limited only by the following description. In addition, in the description of the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

1: Pedal rod
2: Boosting body
3: Reaction disk
4: booster rod
5: Chamber
6: Piston
7: Cylinder
8: Mobile displacement measurement sensor
10: first pressure device
20: second pressure device
40: pressure balancing device;
100: pedal chamber
101: push rod
102: Eurohole
103: pedal piston
105, 303: return spring
107, 207, 209, 407: Shilling
110: pedal chamber euro
120: flow path of the pedal chamber
200: boosting chamber
201: screw
203: bearing
205: nut
210: boosting chamber euro
300: master chamber
301: master piston
310: Master Chamber Euro
320: Master chamber supply flow
400: first balancing chamber
401: first reaction spring
405: second reaction spring
403: balancing piston
410: balancing chamber euro
420: center chamber
430: second balancing chamber
500: motor
600: oil reservoir

Claims (19)

In the electric brake booster is applied to the pressure balancing structure to form a braking force by the combined force of the driving force of the motor and the pedal force of the brake pedal according to the operation of the brake pedal of the driver,
A first pressure device for generating a brake fluid pressure therein by a stepping force of the brake pedal according to the operation of the brake pedal by a driver;
A second pressure device in which the same pressure as the first pressure device is formed inside and a driving force of the motor is formed according to the operation of a motor connected to one side;
A master chamber receiving a combined force of the stepping force of the brake pedal and the driving force of the motor from a master piston reciprocating the inside of the second pressure device; And
It includes; a pressure balancing device for maintaining the pressure of the first pressure device acting on one side and the pressure of the master chamber acting on the other side at a predetermined ratio through reaction springs mounted on one side and the other;
An electric brake booster to which a pressure balancing structure is applied, characterized in that a predetermined ratio of the stepping force of the brake pedal and the driving force of the motor is maintained by the pressure balancing device.
The method of claim 1, wherein the first pressure device,
A pedal chamber in which brake hydraulic pressure is generated by the pedal effort of the brake pedal;
A push rod that linearly moves in the pedal chamber according to the operation of the brake pedal; And
One end is coupled to the push rod and the other end of the return spring is connected to the pedal piston to reciprocate inside the pedal chamber according to the linear movement of the push rod; further comprising an electric brake booster with a pressure balancing structure characterized in that it further comprises .
According to claim 2, The pedal chamber,
An electric brake booster with a pressure balancing structure characterized in that it is connected to a supply path of a pedal chamber receiving brake fluid from an oil reservoir at the top.
The method of claim 1, wherein the second pressure device,
An electric brake booster with a pressure balancing structure, characterized in that it is connected to the first pressure device through a pedal chamber flow path.
The method of claim 1, wherein the second pressure device,
An electric brake booster to which a pressure balancing structure is applied, which is formed integrally with the first pressure device.
The method of claim 1, wherein the second pressure device,
A boosting chamber in which the same brake fluid pressure as the first pressure device is formed and the motor is coupled to one side; An electric brake booster to which a pressure balancing structure is applied further comprising a.
The method of claim 1, wherein the second pressure device,
A screw coupled to the motor to rotate in the interior of the second pressure device according to the operation of the motor; And
It is coupled to the screw and linear motion in accordance with the rotational movement of the screw; a nut for transmitting the driving force of the motor to the master chamber; further comprising an electric brake booster with a pressure balancing structure.
The method of claim 7,
The master piston has one side in contact with the nut and the other side is connected to a return spring connected to one end of the master chamber to reciprocate the inside of the second pressure device according to the linear movement of the nut, and the brake pedal to the master chamber Electric brake booster with a pressure balancing structure, characterized in that for transmitting the combined force of the stepping force and the driving force of the motor.
According to claim 1,
Further comprising a pedal sensor for measuring the displacement of the brake pedal,
The pedal sensor is an electric brake booster to which a pressure balancing structure is applied, which is characterized in measuring displacement of one of a brake pedal, a push rod, or a pedal piston.
The method of claim 1, wherein the motor,
An electric brake booster with a pressure balancing structure, wherein a sensor for measuring a rotation angle is built in and the rotation amount of the motor is determined according to the displacement of the brake pedal.
According to claim 1, wherein the master chamber,
Electric brake booster with a pressure balancing structure characterized in that it is connected to the caliper of the ESC module or brake through the master chamber flow path formed in the master chamber.
According to claim 1, wherein the pressure balancing device,
Electric brake booster with a pressure balancing structure, characterized in that it operates under conditions in which pressure is generated in the master chamber while pressure is generated inside the first pressure device.
According to claim 1, wherein the pressure balancing device,
A first balancing chamber having the same pressure as the master chamber;
A second balancing chamber having the same pressure as the first pressure device;
A center chamber positioned between the first balancing chamber and the second balancing chamber and forming a closed space; And
The first reaction force spring is mounted on one side is in contact with the first balancing chamber, the second reaction force spring is mounted on the other side is in contact with the second balancing chamber; a balancing piston, characterized in that it further comprises; Brake booster.
The method of claim 13, wherein the balancing piston,
When the ratio of the pressure of the first pressure device and the pressure of the master chamber is different from a predetermined ratio, the pressure of the first pressure device and the master chamber is increased as the first reaction spring is compressed and the second reaction spring is tensioned. Electric brake booster with a pressure balancing structure characterized in that it is maintained at a predetermined ratio.
The method of claim 13,
An electric brake booster to which a pressure balancing structure is applied, characterized in that the first balancing chamber and the master chamber are connected, and the second balancing chamber and the first pressure device are connected.
The method of claim 13,
An electric brake booster with a pressure balancing structure characterized in that the first balancing chamber and the master chamber are connected and the second balancing chamber and the second pressure device are connected.
The method of claim 13, wherein the balancing piston,
The electric brake booster to which the pressure balancing structure is applied is characterized in that the surface area of one side in contact with the second balancing chamber is formed wider than the surface area of the other side in contact with the first balancing chamber.
The method of claim 13, wherein the center chamber,
An electric brake booster with a pressure balancing structure characterized in that a flow path connected to the oil reservoir is formed and the brake fluid is full therein.
The method of claim 13, wherein the center chamber,
An electric brake booster with a pressure balancing structure characterized in that a passage through which an air is introduced is formed and filled with air therein.

Images