KR100907867B1 - Motor sealing device of brake system - Google Patents

Abstract

The present invention installs a fan stopper so as to rotate together with the rotating shaft of the motor fixed to the modulator block to immediately discharge the oil leaking from the pump side of the modulator block to the outside of the modulator block to prevent the oil from flowing into the motor inside the oil inside the motor The present invention relates to a motor sealing device of a brake system that prevents inflow and prevents a motor failure and at the same time improves the overall product reliability of the antilock brake system. A pair of pistons symmetrically arranged in the pump mounting bore has a pump for pressurizing and discharging oil during ABS pressure braking or pressure holding braking, and a needle bearing is installed at the end of the rotating shaft made of an eccentric part. When driving the pump An anti-lock brake system having a motor for tightening and a bearing bore machined on the side of the modulator block orthogonally to the center of the pump mounting bore so that the needle bearing is located between a pair of pistons, the fan stopper is press-fitted to the rotating shaft of the motor. And the fan stopper is an invention that can be achieved by providing a gap between the circumferential surface and the second bearing bore so as to rotate smoothly with the rotating shaft.

Brake System, Motor, Seal

Description

SEALING DEVICE OF A MOTOR FOR BRAKE SYSTEM}             

1 is a partial cross-sectional view showing a motor sealing device of the conventional anti-lock brake system

2 is a hydraulic system diagram showing an anti-lock brake system for a vehicle to which the present invention is applied.

3 is a partial cross-sectional view showing a motor sealing apparatus according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

20: Modulator block 24, 25: Pump

40: motor 41: rotating shaft

42: needle bearing 50: fan stopper

51: gap 210: first bearing bore

220: second bearing bore

The present invention relates to an electronically controlled brake system for a vehicle,

In particular, it relates to a motor sealing apparatus of a brake system in which a motor for driving a pump embedded in a modulator block is mounted on an outer surface of the modulator block.

In general, the vehicle is equipped with a hydraulic brake for braking the front wheel and the rear wheel, a hydraulic power unit for forming and transmitting the braking hydraulic pressure to the hydraulic brake side, and a master cylinder, so that the braking hydraulic pressure is formed when the driver presses the brake pedal. To generate braking force. However, when the driver presses the brake pedal to control the increase / maintenance of the braking force, if the braking pressure is greater than the road surface or the friction force of the hydraulic brake is greater than the braking force generated from the tire or the road surface, the tire slips on the road surface. Is generated.

In order to effectively prevent such slip phenomenon and to obtain a strong and stable braking force, the anti-lock brake system includes a plurality of solenoid valves, accumulators and pumps for controlling the braking hydraulic pressure transmitted to the hydraulic brake side.

That is, the conventional vehicle anti-lock brake system includes a modulator block provided with a plurality of solenoid valves, an accumulator and a pair of pumps, an ECU mounted to cover one side of the modulator block and controlling an electrically operated component, and a modulator. It is provided with a motor coupled to the other side of the block to drive a pair of pumps simultaneously.

The modulator block is a rectangular parallelepiped block made of aluminum, and a plurality of solenoid valves are mounted on one side thereof to substantially control the braking hydraulic pressure delivered to the hydraulic brake side. These solenoid valves are divided into NO type solenoid valves connected to the upstream side of the hydraulic brake and NC type solenoid valves connected to the downstream side, which are controlled by the ECU.

In other words, the ECU is mounted to cover the one side of the modulator block in which the circuit board is disposed and the solenoid valve is installed. The ECU detects the vehicle speed through each wheel sensor mounted on the front wheel and the rear wheel, and thereby opens and closes each solenoid valve. The motor drive is controlled.

The accumulator is divided into a low pressure accumulator for temporarily storing oil discharged from the hydraulic brake side in the decompression mode and a high pressure accumulator for reducing pressure pulsation of the oil discharged from the pump in the pressure increasing or holding mode.

That is, the low pressure accumulator is independently provided downstream of the NC type solenoid valve, and the high pressure accumulator is a damping chamber, which is arranged in series with the low pressure accumulator, and an orifice is provided at the outlet.

As shown in FIG. 1, the pair of pumps 2 and 3 are installed symmetrically on both sides of the pump mounting bore 1a machined transversely in the modulator block 1, and the low pressure accumulator The oil in the radar (not shown) is pressurized to pump the high pressure accumulator (not shown). That is, the pump-mounted bore 1a compresses and pumps oil by linear reciprocating motion, and the inlet valves 2a and 3b with the inlet valves 2b and 3b and the outlet valve for preventing backflow of the pumped pressurized oil. (2c) and 3c are provided symmetrically.

As described above, the motor 4 is installed on one side of the modulator block 1, and includes a seal for preventing the inflow of oil and foreign substances on the front cover on which the rotating shaft 4a of the motor 4 protrudes. The front surface is fixedly installed in contact with one side of the modulator block (1).

Therefore, when the motor 4 is mounted on the side of the modulator block 1, the tip of the rotating shaft 4a on which the needle bearing 5 is installed is disposed in the first bearing bore 1b, thereby providing a pair of pistons 2a and 3a. At the same time, the oil stopper 6 is press-fitted into the second bearing bore 1c to prevent oil from the modulator block 1 from flowing into the motor 4.

Next, the operation of the conventional anti-lock brake system configured as described above will be described.

First, in a vehicle equipped with a conventional anti-lock brake system, the brake pedal is applied while driving for the purpose of deceleration or stop. When the braking pressure is greater than the road condition, slip occurs, and the ECU detects the slip through a wheel sensor. .

In this case, the NC type solenoid valve is opened to remove the oil in the hydraulic brake to lower the braking pressure, thereby preventing the vehicle from slipping on the road surface. At this time, the oil discharged through the NC-type solenoid valve is moved to the low pressure accumulator and stored for a while.

On the other hand, when the depressurization state lasts for a long time or the frictional force on the tire and the road surface increases, the braking efficiency of the vehicle decreases, so that the pair of pumps 2 and 3 are operated by driving the motor 4 to increase the braking hydraulic pressure. .

That is, as the rotary shaft 4a of the motor 4 is rotated, the pistons 2a and 3a of the pump 2 and 3 which are in contact with the needle bearing 5 reciprocate, and thus the low pressure accumulator As the suction pressure of the oil stored in the regulator rises, it is led to the high pressure accumulator and transferred to the master cylinder or the NO solenoid valve.

However, in the conventional anti-lock brake system, a small amount of oil leaks through the first bearing bore 1b and the second bearing bore 1c while the motor 4 is driven to pump the oil, and the oil 4 is supplied to the motor 4. There is a problem that the electric drive unit is introduced into the motor (4) with a built-in through the opening of the cover provided in the front portion.

That is, O-rings 2d and 3d are provided on the outer periphery of the pistons 2a and 3a to linearly reciprocate, but the inner periphery of the pump mounting bore 1a and the seals 2d and 3d are Through a small gap, a small amount of oil flows out to the side of the first bearing bore 1b in which the needle bearing 5 is disposed, and then it leaks out to the side of the installed second bearing bore 1c.

In particular, in the conventional configuration as described above, the oil stopper 6 is installed in the second bearing bore 1c to prevent the leaked oil from flowing into the motor 4, but the oil stopper 6 Since it is press-fitted into the second bearing bore 1c of the modulator block 1, a gap is generated between the inner diameter of the oil stopper 6 and the motor 4, and when the oil stopper 6 uses oil for a long time, the motor 4 ) To guide you.

That is, the minute amount of oil leaked while the motor 4 is pumping oil is accumulated in the second bearing bore 1c in which the oil stopper 6 is installed through the first bearing bore 1b. In the end, the oil flows through the gap 6a between the inner diameter of the oil stopper 6 and the motor 4, and the oil flowing into the gap 6a is a portion from which the rotating shaft 4a of the motor 4 is drawn out. This results in the inflow of oil into the motor (4), thereby increasing the electrical resistance inside the motor (4), and in severe cases acts as a cause of product failure, resulting in overall product reliability of the anti-lock brake system. There was this markedly falling issue.

Accordingly, an object of the present invention is to install a fan stopper so as to rotate together with the rotation shaft of the motor fixed to the modulator block to immediately discharge the oil leaking from the pump side of the modulator block to the outside of the modulator block to prevent the motor from flowing into the motor. The present invention provides a motor sealing device of a brake system that prevents oil from entering the inside, thereby preventing motor failure and at the same time, further improving the overall product reliability of the antilock brake system.

The object of the present invention is a pump having a modulator block in which a pump mounting bore is processed in a horizontal direction, and a pair of pistons symmetrically disposed in the pump mounting bore to pressurize and discharge oil during ABS pressure braking or pressure holding braking. And a needle bearing is installed at the end of the eccentric part and mounted on the side of the modulator block so that the motor for driving the pump is perpendicular to the center of the pump mounting bore on the side of the modulator block so that the needle bearing is positioned between the pair of pistons. In the anti-lock brake system having a bearing bore that is machined, the fan stopper is pressed into the rotating shaft of the motor, and the fan stopper is provided with a gap between the circumferential surface and the second bearing bore so as to rotate smoothly with the rotating shaft. Characterized in that configured.

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

2 is a hydraulic system diagram of an antilock brake for a vehicle to which the present invention is applied, and FIG. 3 is a partial cross-sectional view showing a motor sealing apparatus according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the vehicle anti-lock brake system to which the present invention is applied includes a plurality of solenoid valves 21A and 21B and a low pressure high pressure accumulator 22 for controlling hydraulic pressure transmission to the hydraulic brake 13 side. (23) and a pair of pumps (24, 25) is built in, the ECU 30 for controlling the electric drive element, and a pair of pumps (24) mounted on the modulator block (20) (25) is provided with a motor 40 capable of driving at the same time.                     

The modulator block 20 is composed of an aluminum cuboid block. On one side of the modulator block 20, a plurality of NO and NC solenoid valves 21A and 21B which are connected to the upstream and downstream sides of the hydraulic brake 13 are compactly disposed and transmitted to the hydraulic brake 13 side. To control the braking hydraulic pressure. The opening and closing operations of the solenoid valves 21A and 21B are respectively controlled by the ECU 30 which detects the vehicle speed through the wheel sensors 31 disposed on the front wheels and the rear wheels.

3 and 4, the ECU 30 is coupled to cover the solenoid valves 21A and 21B on one side of the modulator block 20 and based on a signal input from the wheel sensor 31 therein. Circuit boards (not shown) for controlling the application of power are provided on the solenoid valves 21A and 21B and the motor 40 side.

Then, the low pressure high pressure accumulator 22 (23, see Fig. 2) is made through the bore processing on the lower surface of the modulator block 20, the NC-type solenoid valve 21B is opened in accordance with the reduced pressure braking action The oil discharged from the hydraulic brake 13 is temporarily stored in the low pressure accumulator 22, and the pump 24 and 25 are driven by the boost / hold braking action so that the oil discharged under pressure is a high pressure accumulator ( 23) to reduce the pressure pulsation.

The pair of pumps 24 and 25 are simultaneously driven by the motor 40 to suck oil stored in the low pressure accumulator 22 to pump the pressure to the high pressure accumulator 23. In order to configure the pumps 24 and 25, the pump mounting bore 26 is machined in a cylindrical shape on the modulator block 20 in a horizontal direction, and the low pressure accumulator ( 22) and a high pressure accumulator (23).

The pump mounting bore 26 is capable of reciprocating from side to side and includes pistons 24B and 25B having inlet valves 24A and 25A at the front end and return springs for restoring the pistons 24B and 25B. 24C), 25C, and the outlet valve 24D, 25D which closes the end of the pump mounting bore 26 and opens and closes opposite to the inlet valve 24A, 25A according to the position of the piston 24B, 25B. The valve housings 24E and 25E are provided. The pistons 24B and 25B reciprocate inside the pump mounting bore 26 by eccentric rotation of the eccentric portion 44A of the rotating shaft 44, which will be described later. O-rings 24F and 25F are installed on the outer circumference of the pistons 24B and 25B to prevent oil leakage during operation. Inlet valves 24A and 25A are directly connected to suction ports, and outlet valves 24D and 25D are connected to discharge ports to prevent backflow of oil.

In addition, the motor 40 is a general DC motor, and is mounted on the other side of the modulator block 20, and a ring-shaped seal is disposed along the edge so as to be pressed on the side of the modulator block 20 on the front surface of the modulator block 20. The front end of the rotary shaft 41 is provided between the one side piston 24B and the other side piston 25B when the motor 40 is mounted, which includes needle bearings for simultaneously driving both side pistons 24B and 25B. 42 is disposed.

In order to install the needle bearing 42, a first bearing bore 210 is provided in the modulator block 20, and a second bearing bore 220 is provided in the modulator block 20 so as to follow the first bearing bore 210. To immediately discharge oil flowing through the first bearing bore 210 from the pumps 24 and 25 in the modulator block 20 to the outside of the modulator block 20 through the second bearing bore 220. Make it work.

The oil discharge is press-fitted to the rotary shaft 41 of the motor 40 to be rotated together with the rotary shaft 41, the pan stopper 50 is located in the second bearing bore 220 so that the fan stopper 50 is Rotating with the rotary shaft 41 is configured to discharge the leaked oil through the gap 51 so as not to approach the motor 40

The following describes the operation and effects of the vehicle antilock brake system configured in this way.

First, the driver steps on the brake pedal 10 in order to decelerate the vehicle or maintain the stopped state. In the normal braking operation, the braking hydraulic pressure generated in the master cylinder 12 through the amplified back pressure from the back power device 11 is NO. By transmitting to the hydraulic brake 13 side through the solenoid valve 21A, a braking action of the vehicle is achieved. On the contrary, when the driver releases little or completely from the brake pedal 10, the oil pressure in the hydraulic brake 13 is returned to the master cylinder 12 again through the NO type solenoid valve 21A and the braking force is reduced or braked. The action is completely released.

The frictional force of the hydraulic brake 13 generated by the brake pressure due to the braking pressure is increased when the driver makes the braking pressure larger than the road surface state or the road surface condition is changed while controlling the braking force increase / hold state for the purpose of deceleration or stopping while driving. If the braking force generated from the tire or the road surface is greater, a slip phenomenon occurs in which the tire slides on the road surface.

As a result of this slip phenomenon, the vehicle loses steering power and the braking distance increases, but ABS control is required because the vehicle rotates. The ABS is controlled in three modes, such as depressurization, boosting, and maintenance, based on signals input from the wheel sensors 31 disposed at the front and rear wheels of the vehicle, and each control state is adjusted to the same state for both the front wheel and the rear wheel. It is not controlled by the friction conditions, that is, a mixture of three modes.

First, the braking pressure decompression operation of the vehicle anti-lock brake system for a vehicle will be described. If the braking pressure in the hydraulic brake 13 is greater than the road surface condition while braking is being performed, the braking pressure should be lowered to an appropriate pressure. Accordingly, the ECU 30 opens and operates the NC type solenoid valve 21B so that the oil coming out of the hydraulic brake 13 is temporarily stored in the low pressure accumulator 22. At this time, each NC type solenoid valve 21B opening operation is performed simultaneously or separately. Through this process, the braking pressure in the hydraulic brake 13 is lowered to prevent the sliding phenomenon on the road surface.

The following describes the braking pressure boosting operation of the antilock brake system. When the depressurization state lasts for a long time during ABS control or the vehicle proceeds to a place where the road friction coefficient is high, the friction force that can be generated on the tire and the road surface is increased than the braking pressure in the hydraulic brake 13 can be applied. A case in which the vehicle braking efficiency is lowered occurs. The ECU 30 judges such a situation on the basis of the signal input from the wheel sensor 24 and drives the motor 40 to increase the braking pressure in the hydraulic brake 13 so that the pumps 24 and 25 are driven. Works. Accordingly, the brake oil temporarily stored in the low pressure accumulator 22 is pressurized by the reciprocating motion of the pistons 24B and 25B, and the high pressure accumulator 23 is provided through the outlet valves 24D and 25D. Discharged into the chamber reduces the pressure pulsation of the oil. Subsequently, the oil having reduced pressure pulsation is transferred to the hydraulic brake 13 through the open-type NO solenoid valve 21A to increase the braking hydraulic pressure.

During the ABS control, the braking pressure maintenance operation is performed to maintain the braking pressure at a constant state in order to reach a state in which the braking pressure in the hydraulic brake 13 generates an optimum braking force or to prevent resonance of the vehicle derived during the ABS control. need. That is, the pressure holding operation eliminates the pressure change in the hydraulic brake 13 mounted on the front wheel and the rear wheel of the vehicle, which closes the NO type solenoid valve 21A on the hydraulic brake 13 side to maintain the braking pressure. To stop the transmission of hydraulic pressure. Accordingly, the pressurized oil discharged from the pumps 24 and 25 is transferred to the master cylinder 12 side, whereby the braking pressure holding operation is performed.

As such, when the power is applied to the motor 40 during the braking pressure boosting operation and the pressure holding operation, the rotary shaft 41 on which the needle bearing 42 is disposed rotates, whereby the one piston 24B and the other piston ( By operating 25B), the oil in the low pressure accumulator 22 is pressurized and transferred to the NO type solenoid valve 21A or the master cylinder 12 side.

During the reciprocating movement of the pistons 24B and 25B, a small amount of oil is leaked through the clearance between the pump mounting bore and the O-rings 24F and 25F, and the oil is discharged from the first bearing bore 210. Flows toward the second bearing bore 220 and then along the gap 51 in close contact with the second bearing bore 220 by the centrifugal force of the fan stopper 50 rotating together with the rotating shaft 41. It is discharged to the outside.                     

That is, oil flowing out of the modulator block 20 may be introduced into the motor 40 through the microcavity between the rotating shaft 41 of the motor 40 and the housing, but the oil to be introduced in this way is the rotating shaft 41. Receive the centrifugal force generated by the rotation of the fan stripper 50 while touching the fan stopper 50 that rotates together with)) is pushed back to the second bearing bore 220, the oil thus pushed is a fan stopper ( Through the gap 51 between the 50 and the second bearing bore 220 is discharged to the outside of the modulator block 20 it is possible to prevent the leaked oil flows into the motor 40 side.

As described above, the present invention installs a fan stopper to be rotated together with the rotating shaft of the motor fixed to the modulator block, thereby immediately discharging oil leaking from the pump side of the modulator block to the outside of the modulator block to prevent the motor from flowing into the motor. This prevents the inflow of oil into the interior and prevents motor failures while also improving the overall product reliability of the antilock brake system.

Claims (1)

Modulator block in which the pump mounting bore is processed in the lateral direction, and a pair of pistons arranged symmetrically in the pump mounting bore to pressurize and discharge oil during ABS pressure braking or pressure holding braking, and the side of the modulator block. Needle bearing is installed at the end of the rotating shaft composed of eccentric part, and the motor for driving the pump and the bearing bore machined orthogonal to the center of the pump mounting bore on the side of the modulator block so that the needle bearing is located between the pair of pistons An anti-lock brake system comprising: a fan stopper press-fitted to a rotation shaft of the motor, the fan stopper having a gap formed between the circumferential surface and the second bearing bore so as to rotate smoothly together with the rotation shaft. The motor sealing of the system.

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