KR101714068B1 - Device for preventing kick-back of Active Hydraulic Booster - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a kickback prevention device for a hydraulic booster, and more particularly, to a kickback prevention device for a hydraulic booster, which prevents a hitting feeling from being transmitted to a brake pedal due to a kickback phenomenon during ABS operation in a regenerative braking system will be.
That is, the present invention separates the control plunger into a buffering plunger and a main plunger so that, even when the output rod of the master cylinder strikes the buffering plunger during ABS operation, shock buffering is performed between the buffering plunger and the main plunger To prevent a shock from being transmitted to the brake pedal during a hitting operation.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a hydraulic booster,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a kickback prevention device for a hydraulic booster, and more particularly, to a kickback prevention device for a hydraulic booster, which prevents a hitting feeling from being transmitted to a brake pedal due to a kickback phenomenon during ABS operation in a regenerative braking system will be.

As is well known, the inner space of the booster for the brake system mounted on the gasoline vehicle is maintained at the atmospheric pressure in the rear space (brake pedal side) around the diaphragm, and the front space is maintained at the vacuum pressure in accordance with the engine negative pressure, The push rod of the master cylinder can be easily pushed due to the difference between the vacuum pressure and the atmospheric pressure.

Alternatively, an electric vehicle running on a motor drive source, or a hybrid vehicle running on an engine and a motor drive source as power sources, can not generate a vacuum degree in accordance with the negative pressure of the engine, It adopts the hydraulic booster (AHB, Active Hydraulic Booster).

Hereinafter, an active hydraulic booster system of an electric vehicle or a hybrid vehicle will be described with reference to the accompanying drawings.

In FIG. 5, reference numeral 10 denotes a master cylinder, which serves to transmit hydraulic pressure to a wheel cylinder for braking friction between a disk constituting a disk brake and a pad.

The first and second pistons 11 and 12 are contained in one side of the master cylinder 10 and the output rod 13 is closely attached to the second piston 12. The direction of the arrow in FIG. A first oil pressure chamber 21 is provided on the left side of the first piston 11 and a second oil pressure chamber 22 is provided between the first and second pistons 11 and 12, 3 hydraulic chambers 23 are formed.

A brake oil tank 16 for supplying hydraulic oil to the first and second hydraulic chambers 21 and 22 is connected to the housing 15 of the master cylinder 10, And an HPU (Hydraulic Power Unit) 30 that provides hydraulic oil acting on the output rod 13 is connected.

A plunger housing 17 is integrally connected to the rear of the master cylinder 10. A control plunger 18 is installed inside the plunger housing 17 such that the control plunger 18 can be moved back and forth. A return spring 19 is disposed in the fourth hydraulic chamber 24 formed on the front face of the control plunger 18 and a brake pedal 26 is connected to the rear end of the control plunger 18 via an input rod 25.

At this time, the third hydraulic chamber 23 of the master cylinder 10 and the fourth hydraulic chamber 24 of the plunger housing 17 are in communication with each other through the hollow holes 27, The front end of the control plunger 18 is sealed to the rear side of the hollow hole 27 by a hydraulic oil shielding seal 28, And the rear end of the output rod 13 inserted into the hollow hole 27 and the front end of the control plunger 18 are spaced apart from each other by a predetermined distance.

The HPU 30 includes an accumulator 34 for temporarily storing hydraulic oil and is provided between the accumulator 34 and the third hydraulic chamber 23 in a state of being closed in a normal state A first solenoid valve 31 is mounted and a second solenoid valve 32 is held between the accumulator 34 and the fourth hydraulic chamber 24 to maintain an open state in a normal state.

Particularly, the pedal simulator 35 is connected to the fourth oil pressure chamber 24 to provide a reaction force corresponding to the braking effort of the driver when the brake pedal 26 is stepped on.

Hereinafter, an operational flow of the conventional active hydraulic booster system having the above-described configuration will be described.

First, when the brake pedal 26 is depressed, the control plunger 18 advances while compressing the return spring 19 while the pedal stroke sensor (not shown) is operated to detect the forward movement of the control plunger 18 The hydraulic oil in the fourth hydraulic chamber 24 enters the accumulator 34 through the second solenoid valve 32 and enters the pedal simulator 35 at the same time.

At this time, the hydraulic oil in the fourth oil pressure chamber 24 acts on the piston 39 in the pedal simulator 35 and the piston 39 compresses and descends the spring 37, so that the driver can move the brake pedal 26 When you step on, you will feel the reaction force that reflects the driver's braking will.

At the same time, when the detection signal of the pedal stroke sensor is transmitted to the HPU 30, the HPU 30 controls the opening of the first solenoid valve 31 so that the hydraulic oil temporarily stored in the accumulator 34 And is supplied to the hydraulic chamber 23 to push the output rod 13 in the forward direction.

The oil in the brake oil tank 16 is supplied to the first and second hydraulic chambers 21 and 22 formed in the housing 15 of the master cylinder 10 so that the output rod 13 is advanced When the second piston 12 is pushed, the second piston 12 advances while compressing the oil in the second hydraulic chamber 22, and at the same time, the first piston 11 compresses the oil in the first hydraulic chamber 21 .

When the oil in the first and second oil pressure chambers 21 and 22 is supplied to the wheel cylinder 20 due to the compression advance of the first and second pistons 11 and 12, Friction braking is performed.

However, the conventional active hydraulic booster system has the following problems.

In the hydraulic dump in which hydraulic oil is repeatedly backward from the wheel cylinder 20 to the master cylinder 10 during ABS (Anti-lock Brake System) operation, as shown in FIG. 6, The first and second pistons 11 and 12 in the master cylinder 10 instantaneously move back and the output rod 13 in contact with the second piston 12 instantaneously returns to the master cylinder. Is backward.

At this time, since the brake pedal 26 is depressed during the ABS operation, the control plunger 18 is advanced, and the front end of the control plunger 18 is also advanced in the hollow hole 27.

6, the rear end of the output rod 13 is retracted in the hollow hole 27 with the backward movement of the output rod 13, and the kickback instantaneously hits the front end of the control plunger 18, a kick-back phenomenon occurs. This hitting force by the kickback is transmitted to the brake pedal 26 through the control plunger 18, which causes the driver to feel a strong vibration and a foreign body feeling from the brake pedal.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a control plunger which is separated into a buffer plunger and a main plunger so that, even when the output rod of the master cylinder hits the buffer plunger during ABS operation, So that the impact is not transmitted to the brake pedal when the hitting is performed. The present invention also provides a kickback prevention device for a hydraulic booster.

According to an aspect of the present invention, there is provided a hydraulic system comprising: a hydraulic line extending from a hollow hole formed between a third hydraulic chamber of an output rod of a master cylinder and a fourth hydraulic chamber of a plunger housing to an accumulator of the HPU; A third solenoid valve mounted on the hydraulic line; A main plunger having a buffer groove formed on its front surface and a rear end connected to the brake pedal through an input rod so as to be longitudinally arranged in the plunger housing; A return spring that is compressibly disposed between a front wall surface of the fourth hydraulic chamber and a front end portion of the main plunger; A cushion spring inserted into the cushion groove of the main plunger; A shock absorbing plunger having a front end inserted into the hollow hole and a rear end inserted into the buffering groove of the main plunger so as to compress the buffer spring; The kickback prevention device of the hydraulic booster according to the present invention comprises:

According to the present invention, a first oil passage is formed through the central portion of the buffer plunger along the front-rear direction, and a front end portion of the buffer plunger inserted into the hollow hole is connected to the first oil passage And a plurality of second oil passages are formed in a radial direction.

A stopping end of the buffering plunger is integrally formed around the rear end of the buffering plunger, and a stopper is integrally attached to the front end surface of the main plunger so that the stopping end of the stopping end is hooked.

A rubber seal is attached to the front end circumferential surface of the buffer plunger inserted into the hollow hole and the rear end circumferential surface of the output rod.

Through the above-mentioned means for solving the problems, the present invention provides the following effects.

According to the present invention, when the ABS of the electric vehicle or the hybrid vehicle is operated, the output rod of the master cylinder strikes the buffering plunger by the hydraulic pressure reversed from the wheel cylinder to the master cylinder, and shock buffering is applied to the buffering plunger and main The stroke impact caused by the kickback is not directly transmitted to the brake pedal, so that the riding comfort and the driving stability of the driver can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a kickback prevention device of a hydraulic booster according to the present invention;
FIG. 2 is a cross-sectional view showing an operating state of a kickback prevention device of a hydraulic booster according to the present invention,
FIG. 3 is a sectional view showing an operating state of the kickback prevention device of the hydraulic booster according to the present invention during ABS operation;
FIG. 4 is a sectional view showing an operating state of the kick-back preventing device of the hydraulic booster according to the present invention when the HPU fails,
5 is a cross-sectional view showing a conventional hydraulic booster configuration,
6 is a schematic view for explaining a problem in the ABS operation of a conventional hydraulic booster;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1, the first and second pistons 11 and 12 are housed in one side of the master cylinder 10 in the configuration of the active hydraulic booster system of the electric vehicle or the hybrid vehicle, A first hydraulic chamber 21 is formed on the left side of the first piston 11 and a second hydraulic chamber 21 is formed on the left side of the first and second pistons 11, A third oil pressure chamber 23 is formed on the right side of the output rod 13,

A brake oil tank 16 for supplying hydraulic oil to the first and second hydraulic chambers 21 and 22 is connected to the housing 15 of the master cylinder 10, And an HPU (Hydraulic Power Unit) 30 that provides hydraulic oil acting on the output rod 13 is connected.

A plunger housing 17 is integrally connected to the rear of the master cylinder 10. A control plunger 18 is installed inside the plunger housing 17 such that the control plunger 18 can be moved back and forth. A return spring 19 is disposed in the fourth hydraulic chamber 24 formed on the front face of the control plunger 18 and a brake pedal 26 is connected to the rear end of the control plunger 18 via an input rod 25.

At this time, the third hydraulic chamber 23 of the master cylinder 10 and the fourth hydraulic chamber 24 of the plunger housing 17 are in communication with each other through the hollow holes 27.

Particularly, in the HPU 30, an accumulator 34 for temporarily storing hydraulic oil is included, and between the accumulator 34 and the third hydraulic chamber 23 is maintained a normally closed state A first solenoid valve 31 is mounted and a second solenoid valve 32 is held between the accumulator 34 and the fourth hydraulic chamber 24 to maintain an open state in a normal state.

A pedal simulator 35 is connected to the fourth oil pressure chamber 24 to provide a reaction force corresponding to the driver's braking effort when the brake pedal 26 is depressed.

In order to constitute the kickback prevention apparatus according to the present invention, between the third hydraulic chamber 23 in which the output rod 13 of the master cylinder 10 exists and the fourth hydraulic chamber 24 of the plunger housing 17 A separate hydraulic line 36 is formed from the hollow hole 27 formed in the hydraulic unit 30 to the accumulator 34 of the HPU 30.

At this time, a third solenoid valve 33, which is opened when the brake pedal is depressed even when the ABS is operated or not operated and is normally closed, is mounted on the hydraulic line 40.

Particularly, the kickback prevention apparatus of the present invention is characterized in that, when the brake pedal is depressed, the existing control plunger advancing by the pressing force is separated into the main plunger 40 and the buffer plunger 42.

The rear end of the main plunger 40 is connected to the brake pedal 26 via an input rod 25 and the front end of the plunger housing 17 is provided with a buffer groove 41 Is formed.

A return spring (not shown) is provided in the space between the front end of the fourth hydraulic chamber 24, that is, the front end of the main plunger 40 and the front end wall of the plunger housing 17 to provide an elastic restoring force for backward movement of the main plunger 40 19 are compressibly arranged and a buffer spring 38 is compressibly contained in the buffer groove 41 of the main plunger 40. [

The buffering plunger 42 is provided with a piston structure in which the front end thereof is inserted into the hollow hole 27 and the rear end thereof is inserted into the buffering groove 41 of the main plunger 40 so as to compress the buffering spring 38.

Particularly, in the center of the buffer plunger 42, a first oil passage 43 is formed to pass through the hollow hole 27 and the buffer groove 41 of the main plunger 40 along the front-rear direction, The front end portion of the shock absorber plunger 42 inserted into the hollow hole 27 is provided with four second oil passages 44 in the radial direction at four positions of the first oil passage 43 so as to coincide with the hydraulic line 36 .

The brake oil filled in the hollow hole 27 is also filled into the buffer groove 41 of the main plunger 40 through the first oil passage 43 and the second oil passage 43 is filled with the hydraulic oil in the hydraulic line 36 As shown in Fig.

At this time, a latching end 46 having a seal 45 is integrally formed around the rear end of the buffering plunger 42. The latching end 46 of the main plunger 40 is engaged with the front end surface of the main plunger 40, A stopper 47 capable of limiting the advancing distance of the plunger 42 is integrally attached.

The airtightness of the hydraulic oil in the hollow hole 27, that is, the brake oil, to the peripheral surface of the front end portion of the shock absorber plunger 42 inserted into the hollow hole 27 and the rear end surface of the output rod 13, A rubber seal 48 is attached.

Hereinafter, the operation of the kickback prevention apparatus of the present invention will be described.

When ABS is not operated and ABS is released

2, when depressing the brake pedal 26, the detection operation of the pedal stroke sensor (not shown) is performed, and at the same time, the third solenoid valve 33 is opened and the brake pedal 26 The main plunger 40 advances while compressing the return spring 19. As shown in Fig.

At the same time, the oil pressure in the buffering groove 41 in the main plunger 40 acts on the buffering plunger 42 to advance the buffering plunger 42, The oil in the hollow hole 27 is temporarily stored in the accumulator 34 through the hydraulic line 36 and the open third solenoid valve 33 so that the pressure is not transmitted to the output rod 13.

At this time, the buffer plunger 42 and the main plunger 40 maintain a constant spacing c because the tension of the buffer spring 38 is larger than the tension of the return spring 19. [

Therefore, when the detection signal of the pedal stroke sensor is transmitted to the HPU 30, the HPU 30 controls the opening of the first solenoid valve 31 so that the oil in the accumulator 34 flows into the third hydraulic chamber 23, And pushes the output rod 13 in the forward direction.

The oil in the brake oil tank 16 is supplied to the first and second hydraulic chambers 21 and 22 formed in the housing 15 of the master cylinder 10 so that the output rod 13 is advanced When the second piston 12 is pushed, the second piston 12 advances while compressing the oil in the second hydraulic chamber 22, and at the same time, the first piston 11 compresses the oil in the first hydraulic chamber 21 .

Accordingly, when the oil in the first and second oil pressure chambers 21 and 22 is supplied to the wheel cylinder 20 due to the compression advance of the first and second pistons 11 and 12, Friction braking is performed.

ABS operation

A hydraulic dump in which the hydraulic oil is repeatedly driven backward from the wheel cylinder 20 to the master cylinder 10 is generated at the time of operation of the anti-lock brake system (ABS) as shown in FIG. 3, When the oil in the cylinder instantaneously returns to the master cylinder, the first and second pistons 11 and 12 in the master cylinder 10 instantaneously move back and the output rod 13 ) Will be backward.

As a result of the backward movement of the output rod 13 as described above, the rear end of the output rod 13 is retracted in the hollow hole 27, and the kickback is instantaneously struck at the front end of the buffer plunger 42, A phenomenon occurs.

At this time, the oil in the hollow hole 27 passes through the hydraulic line 36 and the open third solenoid valve 33 and is temporarily stored in the accumulator 34.

When the buffering plunger 42 moves backward due to such a kickback phenomenon, the buffering plunger 42 compresses the buffer spring 38 to buffer the shock due to the kickback phenomenon.

Therefore, the impact due to the kickback phenomenon is not transmitted to the brake pedal 26, so that the driver does not feel a strong vibration and a foreign body feeling from the brake pedal.

HPU fail

When the HPU 30 including the accumulator 34 and the first, second and third solenoid valves 31, 32 and 33 fails, the first and second solenoid valves 31 and 32 are closed The oil pressure acting on the output rod 13 can not be supplied and the hydraulic pressure for braking may not be transmitted to the wheel cylinder.

At this time, the third solenoid valve 33 is also closed so that the oil in the hollow hole 27 becomes a closed circuit state in which it can not escape to the accumulator side through the hydraulic line 36.

4, the main plunger 40 advances while compressing the return spring 19, and at the same time, the main plunger 40 moves in the cushion groove 41 in the main plunger 40 The oil in the hollow hole 27 flows into the hydraulic line 36 and the third solenoid valve 33 in the open state, So that the oil in the hollow hole 27 directly acts on the output rod 13.

When the output rod 13 is advanced and the second piston 12 is pushed forward, the second piston 12 advances while compressing the oil in the second hydraulic chamber 22, The oil in the first and second oil pressure chambers 21 and 22 is advanced while compressing the oil in the first oil pressure chamber 21 and the oil in the first and second oil pressure chambers 21 and 22 is transmitted to the wheel cylinder 20 ) So that friction braking between the disk brake disk and the pad can be performed even under the condition of HPU failure.

10: master cylinder 11: first piston
12: second piston 13: output rod
15: housing 16: brake oil tank
17: plunger housing 18: control plunger
19: return spring 20: wheel cylinder
21: first hydraulic chamber 22: second hydraulic chamber
23: third hydraulic chamber 24: fourth hydraulic chamber
25: Input load 26: Brake pedal
27: hollow hole 28: sealing
30: HPU 31; The first solenoid valve
32: second solenoid valve 33: third solenoid valve
34: Accumulator 35: Pedal simulator
36: Hydraulic line 37: Spring
38: buffer spring 39: piston
40: main plunger 41: buffering groove
42: buffering plunger 43: first oil passage
44: second oil passage 45: sealing
46: Retaining end 47: Stopper
48: Rubber seal

Claims (4)

The accumulator of the HPU 30 from the hollow hole 27 formed between the third oil pressure chamber 23 in which the output rod 13 of the master cylinder 10 exists and the fourth oil pressure chamber 24 of the plunger housing 17, (34);
A third solenoid valve 33 mounted on the hydraulic line 36;
A main plunger 40 having a buffer groove 41 formed on its front side and a rear end connected to the brake pedal 26 via an input rod 25 so as to be movable forward and backward in the plunger housing 17;
A return spring 19 that is compressibly disposed between the front wall surface in the fourth hydraulic chamber 24 and the front end of the main plunger 40;
A cushion spring (38) inserted into the cushion groove (41) of the main plunger (40);
A shock absorbing plunger 42 inserted into the hollow hole 27 at the front end and inserted into the shock absorbing groove 41 of the main plunger 40 so as to compress the shock absorbing spring 38;
Lt; / RTI >
A first oil passage 43 is formed in the central portion of the buffering plunger 42 so as to communicate with the buffering groove 41 of the main plunger 40 through the hollow hole 27, A plurality of second oil passages 44 are formed in a radial direction from the first oil passage 43 so as to be coincident with the hydraulic line 36 at the front end portion of the buffer plunger 42 inserted into the second oil passage 27 Features a hydraulic booster kickback prevention device.
delete The method according to claim 1,
A stopper 46 is integrally formed around the rear end of the shock absorbing plunger 42. A stopper 47 is provided on the front end surface of the main plunger 40 so that the stopping end 46 is in contact with the stopper 46 ) Are integrally attached to each other.
The method according to claim 1,
Wherein a rubber seal (48) is attached to the front end circumferential surface of the buffering plunger (42) inserted into the hollow hole (27) and the rear end circumferential surface of the output rod (13) .

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