KR100366714B1 - Oil passage control apparatus of electronic power controlled power steering system - Google Patents

Abstract

The present invention relates to a flow path control apparatus for an electronically controlled power steering system, and has an object to provide a stable steering feeling to a driver by controlling a flow path of a hydraulic system during a high speed driving of a vehicle.

The present invention for achieving the above object, the first spool (1); Located at the rear of the first spool 1, the outer peripheral portion is formed with a protruding end (2a), the rear end of the second spool having an insertion groove (2b) that can be inserted into the front end of the first spool ( 2) and; First and second springs (3, 4) for restoring them to their original states when the first and second spools (1) and (2) are moved; The first and second spools (1, 2) and the first and second springs (3, 4) are embedded therein, and the first and second chambers (5a, 5b) through which oil flows are provided. And an orifice 5f is formed between the second chambers 5a and 5b, and the oil reservoir tank 10 side passes through the second chamber 5b from the bypass flow path 20 'on the oil pump 40 side. First and second openings 5c and 5d which are opened and closed by the first spool 1 while being communicated with the bypass flow path 20 'of the bypass flow path 20', and the bypass flow path 20 'on the oil pump 40 side is formed. ) And a valve body 5 having a third cylinder 5e for communicating the first chamber 5a; It is characterized by consisting of a solenoid 6 inserted into the rear end of the valve body 5 to advance or retract the first spool 1.

Description

Oil control system of electronically controlled power steering system {OIL PASSAGE CONTROL APPARATUS OF ELECTRONIC POWER CONTROLLED POWER STEERING SYSTEM}

The present invention relates to a flow path control device for an electronically controlled power steering system, and more particularly, to a flow path control device for an electronically controlled power steering system that provides a stable steering feeling to a driver during a steering operation according to a vehicle speed of a vehicle.

In general, in the steering system for changing the driving direction of the vehicle, when a larger operation force for the steering wheel is required or when a quick operation is required, a power steering apparatus provided with a power booster is introduced to cope with this.

In the electronically controlled power steering system, the microprocessor control unit and the solenoid valve precisely control the hydraulic system according to the driving conditions of the vehicle detected by the vehicle speed sensor, etc., thereby giving the driver a light and comfortable steering feeling at low speeds. In high-speed operation, it provides a good steering stability along with a solid steering feeling, and provides an optimal steering condition to the driver such that rapid steering is achieved in an emergency situation.

That is, the solenoid valve is mounted on the valve part of the rack / pinion gear, and the solenoid valve receives a signal from the vehicle speed sensor and controls the flow path of the hydraulic system according to the changed value so that the driver has a stable steering feeling.

The flow path control system using the solenoid valve is described in detail in Korean Patent Application No. 1997-46706.

However, the flow path control system made in the above-described conventional solenoid valve structure has a problem in that it cannot effectively control a phenomenon in which the steering wheel feels light at the same time as in high-speed driving, and thus does not provide a stable steering feeling to the driver.

The present invention is to solve the above problems, the electronically controlled power steering system of controlling the flow path of the hydraulic system according to the vehicle speed situation, such as during high-speed driving or low-speed driving of the car to give a stable steering feeling to the driver, especially during high-speed driving An object is to provide a flow path control device.

1 is a block diagram showing a flow path control device and a hydraulic system according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: 1st spool 2: 2nd spool

2a: protrusion 2b: insertion groove

3: first spring 4: second spring

5: valve body 5a: first chamber

5b: 2nd chamber 5c: 1st port

5d: 2nd port 5e: 3rd port

5f: Orifice 6: Solenoid

The present invention for achieving the above object, the first spool; A second spool positioned at the rear of the first spool, having a protruding end formed at an outer circumferential portion thereof, and having an insertion groove formed at a rear end thereof, into which an end portion of the first spool can be inserted; First and second springs for restoring first and second spools to their original state when the first and second spools are moved; The first spool and the second spool and the first spring and the second spring are built-in, and the inside is provided with a first chamber and a second chamber in which oil flows, the orifice between the first chamber and the second chamber And a first through hole and a second through hole which are opened and closed by the first spool while communicating from the bypass flow path on the oil pump side to the bypass flow path on the oil reservoir tank side via the second chamber. A valve body having a third passage for communicating the bypass passage on the oil pump side with the first chamber; And a solenoid inserted into a rear end of the valve body to advance or retract the first spool.

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

1 is a block diagram showing a flow path control apparatus and a hydraulic system according to the present invention.

As shown, the power steering system to which the present invention is applied is provided with an oil reservoir tank 10 filled with oil as a working fluid, and a flow path 20 which is a supply line of oil from the oil reservoir tank 10 is provided. It is drawn out and communicates with the hydraulic control valve 30, one end of the flow path 20 to the hydraulic control valve 30 is provided with an oil pump 40 for providing a transfer pressure for the oil.

The present invention, which is provided in the middle of the bypass flow path 20 'branched from the flow path 20, includes a first spool 1 and a second spool 2 located behind the first spool 1. And a valve body (5) having a first spring (3) and a second spring (4) together for restoring the original state when the first spool (1) and the second spool (2) are moved; The solenoid 6 is inserted into the rear end of the valve body 5 to control the electronic control device (not shown) to move the first spool 1 forward or backward.

In addition, a first chamber 5a and a second chamber 5b through which oil flows are provided in the valve body 5, and between the first chamber 5a and the second chamber 5b. An orifice 5f having a reduced cross-sectional area is formed.

Further, in the valve body 5, the bypass flow passage 20 'on the oil reservoir tank 10 side from the bypass flow passage 20' on the oil pump 40 side to the second chamber 5b. The first passage 5c and the second passage 5d which are opened and closed by the first spool 1 while being communicated with each other are formed, and the bypass passage 20 'of the oil pump 40 side is formed. And a third cylinder 5e for communicating the first chamber 5a with each other.

In addition, a protruding end 2a for opening and closing the second passage 5d is formed at an outer circumferential portion of the second spool 2, and a front end portion of the first spool 1 may be inserted into a rear end portion thereof. The insertion groove 2b is formed.

Referring to the operation of the present invention made as described above are as follows.

First, in the medium to low speed travel, the solenoid 6 moves forward, the leading end of the first spool 1 advances into the insertion groove 2b of the second spool 2, and closes the orifice 5f so that the bypass flow path ( The oil in the 20 ') is prevented from being bypassed, allowing the hydraulic system to act as a lightening steering wheel.

Then, when the vehicle speed increases, the vehicle speed sensor (not shown) which detects this sends a signal to the electronic control device (not shown), and the electronic control device operates the solenoid 6 and is located at the tip of the solenoid 6. The first spool 1 is retracted, and the first spool 1 is retracted while extending the first spring 3 located in front thereof to open the orifice 5f and flow into the third passage 5e. The oil to be flowed to the second chamber (5b) side through the orifice (5f).

Accordingly, the oil which is to be introduced from the oil reservoir tank 10 to the hydraulic control valve 30 side through the oil pump 40 passes through the bypass passage 20 'to the third passage 5e of the valve body 5. And through the first chamber (5a) and through the orifice (5f), the second chamber (5b) and the second passage (5d) to the oil reservoir tank 10, thereby reducing the operating pressure of the power cylinder of the hydraulic system Reduces action.

That is, the steering force to operate the steering wheel is increased as the back action is reduced, which makes the steering wheel feel heavy and the driver has a stable steering feeling.

As described above, the flow path control apparatus of the electronically controlled power steering system according to the present invention provides a stable steering feeling to the driver by controlling the flow path of the hydraulic system according to the vehicle speed situation, such as when driving at high speed or at low speed. In particular, it has the effect of optimizing the steering feeling in high speed driving.

Claims (1)

In the hydraulic system of the power steering system composed of the oil reservoir tank 10, the hydraulic control valve 30, the oil pump 40 and the flow path 20 for communicating them, A first spool 1; Located at the rear of the first spool 1, a protruding end 2a is formed at the outer circumferential portion, and an insertion groove 2b is formed at the rear end thereof, into which the distal end portion of the first spool 1 can be inserted. A second spool (2); A first spring (3) and a second spring (4) for restoring the first and second spools (1, 2) to their original state when the first spool (1) and the second spool (2) are moved; The first spool (1), the second spool (2), the first spring (3) and the second spring (4) is built in, the first chamber (5a) and the second chamber (5b) through which oil flows ) Is provided, and an orifice 5f is formed between the first chamber 5a and the second chamber 5b, and from the bypass passage 20 'on the oil pump 40 side, the second orifice is formed. The first passage 5c and the second passage 5d, which are opened and closed by the first spool 1 while communicating with the bypass passage 20 'on the oil reservoir tank 10 side through the chamber 5b, A valve body 5 formed with a third passage 5e for communicating the bypass passage 20 'on the side of the oil pump 40 with the first chamber 5a; And a solenoid (6) inserted into the rear end of the valve body (5) to advance or retract the first spool (1).