KR100344465B1 - A modulator block of ABS - Google Patents

Abstract

The present invention relates to a modulator block of an anti-lock brake system for a vehicle, and an object thereof is to separately store oil leaking from the pump side to prevent oil from flowing into the motor.

According to the modulator block 20 of the anti-lock brake system for a vehicle according to the present invention, the oil for storing oil flowing out below the positions of the bearing bores 27 and 28 where the needle bearings 48 and the ball bearings 49 are installed. Since the separate oil chamber 29 is processed, oil leaking from the pump 24 and 25 side is stored in the oil chamber 29 without being introduced into the motor 40. Accordingly, there is an advantage that the failure of the motor 40 due to the outflow oil is prevented and the overall product reliability of the antilock brake system is further improved.

Description

Modulator block of vehicle anti-lock brake system

The present invention relates to a vehicle antilock brake system, and more particularly, to a modulator block of an antilock brake system in which a pump is built in and a motor for driving the motor is mounted on an outer surface thereof.

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 is provided with a plurality of solenoid valves, accumulators and pumps for controlling the braking hydraulic pressure transmitted to the hydraulic brake side.

That is, a 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 so that the circuit board is disposed inside and covers one side of the modulator block in which 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 classified into a low pressure accumulator in which oil exiting the hydraulic brake side is temporarily stored 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 to be connected 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, which is machined transversely in the modulator block 1, and has a 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 covers the opening of the housing 4a and the conventional housing 4a which forms an outer body and is open at one side thereof, and along the edge thereof. The cover 4f having the elastic seal 7 disposed thereon, the stator 4b installed inside the housing 4a, and the stator 4b interact with each other to rotate and rotate in the axial direction. The rotor 4c is provided.

The rotating shaft 4d extends through the opening 4g perforated in the center of the cover 4f to the outside. The tip of the rotating shaft 4d is composed of an eccentric portion 4e, and the needle bearing 5 is disposed therein. In order to support this rotating shaft 4d, a ball bearing 6 is provided at the center of the cover 4f.

In addition, the needle bearing 5 coupled to the eccentric portion 4e of the rotation shaft 4d is disposed between the one side piston 2a and the other side piston 3a. For this purpose, the pump mounting portion is mounted on one side of the modulator block 1. The first bearing bore 1b for mounting the needle bearing 5 and the second bearing bore 1c for mounting the ball bearing 6 are stepped so as to communicate in a direction perpendicular to the bore 1a.

Therefore, when the motor 4 is mounted on the side of the modulator block 1, the eccentric portion 4e of the rotating shaft 4d on which the needle bearing 5 is installed is disposed in the first bearing bore 1b, whereby a pair of pistons 2a are provided. It is possible to drive (3a) at the same time, the ball bearing 6 is seated on the second bearing bore (1c) is smoothly the rotational movement of the rotating shaft (4d). In addition, the seal 7 provided on the cover 4f is compressed to the side of the modulator block 1 to prevent foreign matter from entering.

The following describes the operation of the conventional antilock brake system configured as described above.

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 rotation shaft 4d of the motor 4 is rotated, the pistons 2a and 3a of the pump 2 and 3 in contact with the needle bearing 5 reciprocate, and thus the low pressure accumulator The oil stored in the generator is guided to the high pressure accumulator as the suction pressure rises and is transferred back 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 oil, and the oil is covered with the cover 4f. There is a problem that the electric drive is introduced into the motor housing (4a) with the built-in opening (4g) and the like.

That is, O-rings 2d and 3d are provided on the outer periphery of the pistons 2a and 3a for linear reciprocation, but the inner periphery of the pump mounting bore 1a and the seal 2d and 3d are A small amount of oil flows out to the side of the first bearing bore 1b in which the needle bearing 5 is disposed through the fine gap, and then it leaks to the side of the second bearing bore 1c in which the ball bearing 6 is installed. This oil is not escaped to the outside by the seal 7 disposed on the cover 4f so as to be pressed against the side of the modulator block 1, and the oil is interposed between the side of the modulator block 1 and the outer surface of the cover 4f of the motor 4. When the water level reaches the proper level, the water flows into the motor housing 4a through the opening 4g of the cover 4f and the like.

As such, the oil introduced into the motor housing 4a acts as a foreign matter on the electric drive, such as the brush 4h, so that the brush 4h is fixed or the electrical resistance is increased. The overall product reliability of the lock brake system is significantly reduced.

The present invention is to solve this problem, by preventing the oil leaking from the pump side of the modulator block of the present invention to enter the motor, preventing the motor failure and at the same time improve the overall product reliability of the anti-lock brake system It is to provide a modulator block of the vehicle anti-lock brake system which can be improved.

1 is a schematic view showing a pump and a motor mounting structure of a 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 schematic view showing a mounting structure of a modulator block and a motor according to the present invention.

4 is a cross-sectional view taken along line IV-IV of FIG. 3.

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

20 Modulator block 24, 25 Pump

27,28..Bearing Bore 29..Oil Chamber

29A. Oil induction road 40. Motor

47 .. Seal 48 .. Needle Bearing

49..Ball bearings

The present invention for achieving this object is;

Modulator block in which the pump mounting bore is processed in the lateral direction, and a pair of pistons symmetrically arranged in the pump mounting bore, pressurizing and discharging oil during ABS boost or brake operation, and the side of the modulator block The needle bearing is installed at the tip of the rotating shaft composed of eccentric parts, and the bearing bore is machined orthogonally 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. In the equipped anti-lock brake system,

The side of the modulator block is formed below the position of the bearing bore is characterized in that the oil chamber for storing the oil flowing through the bearing bore is provided.

In addition, between the oil chamber and the bearing bore is characterized in that the oil induction path for guiding the outflow oil to the oil chamber side is provided.

In addition, the front of the motor is arranged in the ring-shaped seal along the edge so as to be pressed to the side of the modulator block, the oil chamber is characterized in that the seal is provided inside the portion where the seal is pressed.

According to this configuration, oil leaking from the pump side through the bearing bore is prevented from being stored in the oil chamber and flowing into the motor, thereby preventing motor failure and improving overall product reliability of the antilock brake system. Can be.

Hereinafter, one preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings. 2 is a hydraulic system diagram of an anti-lock brake for a vehicle to which the present invention is applied, and FIGS. 3 and 4 illustrate a modulator block having a motor mounting structure and an oil chamber of an anti-lock brake system according to the present invention. Schematic diagram shown.

In the vehicle anti-lock brake system to which the present invention is applied, as shown in FIG. 2, a plurality of solenoid valves 21A and 21B and low and high pressure accumulators 22 for controlling hydraulic pressure transmission to the hydraulic brake 13 side. Modulator block 20 in which 23 and a pair of pumps 24 and 25 are embedded, ECU 30 for controlling an electric drive element, and a pair of pumps 24 mounted to modulator block 20 A motor 40 capable of simultaneously driving 25 is provided.

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 type solenoid valves 21A and 21B which are associated with 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 and high pressure accumulator 22 (23, see Fig. 2) is formed 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 brake 13 is temporarily stored in the low pressure accumulator 22, and the oil discharged under pressure by driving the pumps 24 and 25 according to the boost / hold braking action is the high pressure accumulator 23. To reduce 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 the horizontal direction, and the low pressure accumulator 22 is formed through the suction port and the discharge port. ) And the 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. Equipped valve housings 24E, 25E and the like are installed. The pistons 24B and 25B reciprocate inside the pump mounting bore 26 by the eccentric rotation of the eccentric portion 44A of the rotating shaft 44, which will be described later, and oil leakage during operation will be applied to the outer circumference of the pistons 24B and 25B. O-rings 24F and 25F are installed to prevent them. 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, which is mounted on the other side of the modulator block 20 and whose front surface is open, the stator 42 installed on the inner circumference of the housing 41, and the stator 42. And the rotor 43 which rotates in interaction with the rotary shaft 44, the rotary shaft 44 that is axially press-fitted in the center of the rotor 43, rotates together, and has an eccentric portion 44A at its tip, and the housing 41. The cover 46 has a perforated opening 46A at its center so that the front surface is closed and the eccentric portion 44A of the rotation shaft 44 penetrates and is exposed to the outside.

On the front surface of the cover 46, a ring-shaped seal 47 is disposed along the edge to be pressed against the side of the modulator block 20, and a ball bearing 49 supporting the rotating shaft 44 smoothly rotates at the center thereof. ) Is installed. And the eccentric portion 44A having a certain amount of eccentricity is located between one side piston 24B and the other side piston 25B when the motor 40 is mounted, and there are needles for simultaneously driving both side pistons 24B and 25B. Bearing 48 is disposed.

In order to install the ball bearing 49 and the needle bearing 48, the other side of the modulator block 20 is bore-processed in a direction orthogonal to the center of the pump mounting bore 26. (28) is provided. The first bearing bore 27 is processed to communicate in a direction orthogonal to the center of the pump mounting bore 26 so that the needle bearing 48 is installed, and the second bearing bore 28 is formed of the first bearing bore 27. The ball bearing 49 is seated by being processed to be wider than the inner diameter.

On the other hand, the other side of the modulator block 20 is provided with an oil chamber 29 for temporarily storing the oil flowing out through the first and second bearing bores (27, 28). The oil chamber 29 is formed as a hollow space in a rectangular shape, and is connected to the first and second bearing bores 27 and 28 through the oil induction path 29A. That is, the oil induction path (29A) is one end is associated with the bottom of the bearing bore (27) 28, and the other end is processed to be associated with the upper portion of the oil chamber 29 to guide the outflow oil into the oil chamber (29). do.

The oil chamber 29 is formed below the position of the first and second bearing bores 27 and 28 so that the spilled oil is guided in the gravity direction along the oil induction path 29A, and the motor 40 cover ( It is preferable to form the inside of the part G to which the seal 47 arrange | positioned at the front surface of 46 is crimped | bonded. In addition, in the embodiment of the present invention, the oil induction path 29A is formed in a groove shape so that the first and second bearing bores 27 and 28 and the oil chamber 29 are connected to each other, but the modulator block 20 When the motor 40 is mounted to maintain a constant interval on the side surface, the spilled oil is introduced into the oil chamber 29 without a separate oil induction path 29A.

The following describes the operation and effects of the vehicle anti-lock brake system configured as described above.

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 so that 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 when the driver increases the braking pressure to the road surface state or changes the road surface condition while controlling the braking force to increase / maintain for the purpose of deceleration or stop while driving is performed. If the braking force generated from the tire or the road surface is greater than that, a slip phenomenon occurs that the tire slips on the road surface. As a result of the slip phenomenon, the vehicle loses steering power and increases the braking distance, and the ABS rotates 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. 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 moves to a place where the road surface 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 through the outlet valves 24D and 25D. It is discharged to reduce 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 power is applied to the motor 40 during the braking pressure boosting operation and the pressure holding operation, the eccentric portion 44A of the rotating shaft 44 on which the needle bearing 48 is disposed eccentrically rotates, thereby causing one side piston. 24B and the other piston 25B have a 180 degree phase difference and reciprocate the inside of the pump mounting bore 26, the oil in the low pressure accumulator 22 is pressurized and the NO type solenoid valve 21A or the master cylinder ( 12) delivered to the side.

During the reciprocating movement of the pistons 24B and 25B, oil is leaked through the clearance between the pump mounting bore 26 and the O-rings 24F and 25F, which are stored in the oil chamber 29. do.

That is, a small amount of oil is modulated by the first bearing bore 27 and the second bearing bore 28 as one piston 24B and the other piston 25B are driven in the pump mounting bore 26. It leaks out to the side, which is stored inflow into the oil chamber 29 along the oil flow path 29A. At this time, since the oil chamber 29 is formed inside the portion G to which the seal 47 disposed on the front surface of the cover of the motor 40 is compressed, as described above, the oil chamber 29 It does not occur when the oil introduced into the outside flows out.

As a result, the oil leaking from the pump 24, 25 side is not stored in the motor 40 housing 41, but is stored in the oil chamber 29 which is processed separately, thereby preventing damage to the motor electric drive unit by the outflow oil. Is prevented.

As described in detail above, according to the modulator block of the vehicle anti-lock brake system according to the present invention, a separate oil chamber for processing oil to be discharged below than the bearing bore position where the needle bearing and the ball bearing are installed is processed. Therefore, oil leaking from the pump side is stored in the oil chamber without entering the motor. Accordingly, there is an advantage that the failure of the motor by the spilled oil is prevented and the overall product reliability of the antilock brake system is further improved.

Claims (3)

A modulator block in which a pump mounting bore is processed in a lateral direction, a pair of pistons symmetrically disposed in the pump mounting bore, and a pump for pressurizing and discharging oil during ABS pressure-induced braking or pressure holding braking; A needle bearing is installed at the end of the rotating shaft formed of an eccentric portion and a motor for driving the pump, and 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 an anti-lock brake system with orthogonally machined bearing bores, Anti-lock brake, characterized in that the side of the modulator block 20 is provided below the bearing bore 27, the oil chamber 29 for storing the oil flowing out through the bearing bore 27 Modulator block of the system. The method of claim 1, Modulator block of the anti-lock brake system, characterized in that between the oil chamber (29) and the bearing bore (27) is an oil induction path (29A) for guiding the outflow oil toward the oil chamber (29). The method of claim 1, On the front of the motor 40 is a ring-shaped seal 47 is arranged along the edge to be pressed to the side of the modulator block 20, The oil chamber (29) is a modulator block of the anti-lock brake system, characterized in that provided in the region (G) where the seal 47 is pressed.