KR20080013490A - Steering system with vibration reducing device and vibration reducing method using of it - Google Patents

Abstract

A steering system with a vibration reducing device and a vibration reducing method using the same are provided to reduce vibration generated by unbalance of wheels of a vehicle by changing weight of a yoke of a steering wheel. A steering system with a vibration reducing device comprises a yoke pressing a rack bar with a constant weight, a vibration sensing unit(200) sensing change of a steering angle of a steering wheel and calculating a vibration number, an actuator(400) pressing the yoke to the rack bar, and a controller(300) analyzing the vibration number calculated by the vibration sensing unit to control the actuator pressing the yoke.

Description

Steering System With Vibration Reducing Device and Vibration Reducing Method Using Of It}

1 is a cross-sectional view showing a part of a rack and pinion type gearbox of a steering apparatus for a vehicle according to the prior art.

Figure 2 is a schematic diagram showing a steering system provided with a vibration reducing device according to the present invention.

3 is a flow chart showing a vibration reduction method using a steering system provided with a vibration reduction device according to the present invention.

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

100: gear box 200: vibration detection means

210: detector 220: calculator

300: control unit 400: actuator

The present invention relates to a steering system provided with a vibration reduction device and a vibration reduction method using the same, and more particularly, to a steering system capable of reducing vibration caused by an imbalance of an automobile wheel by changing a yoke load of a steering device and using the same. It relates to a vibration reduction method.

In general, a steering device for a vehicle is a device for changing a driving direction of a vehicle according to a driver's operation. A steering wheel provided in a driver's seat, a steering shaft provided below the gear, and a gear connected to the steering shaft to switch a power transmission direction. It consists of a box.

Among the components constituting the steering device for the vehicle, the rack and pinion type is most used in the gearbox, and the rack and pinion type gearbox is used to control the force generated by the driver from the steering shaft. Receives a rotating pinion and the rack bar (Rack Gear) to be moved to the left and right by the pinion.

1 is a cross-sectional view showing a part of a rack and pinion type gearbox of a steering apparatus for a vehicle according to the prior art, referring to the rack and pinion type gearbox with reference to the drawings.

As shown in FIG. 1, the gearbox includes a housing 11 forming an external shape, and the pinion shaft 12 and the pinion which receive the rotational force generated by the driver from a steering shaft (not shown) inside the housing 11. A pinion gear 13 formed below the shaft 12 is provided. In addition, a rack bar 15 having a rack gear 14 meshed with the pinion gear 13 is provided on the outer circumference thereof, and the rotational force of the pinion shaft 12 is matched with the pinion gear 13 and the rack gear 14 engaged therewith. Through the horizontal bar is converted to the horizontal motion of the rack bar (15). At this time, the yoke portion 20 that closely supports the rack bar 15 toward the pinion gear 13 from the rear of the rack bar 15 so that the pinion gear 13 and the rack gear 14 are well maintained. Is provided.

The yoke unit 20 is a hollow yoke cylinder 21 formed integrally with the housing 11 at the rear side of the rack gear 14 and is inserted into the yoke cylinder 21 so as to be slidable, and a rack bar at one side thereof. And a yoke 22 formed with a semicircular contact portion which can be in close contact with the outer circumferential surface of 15.

A spring 23 is provided at the rear side of the yoke 22 to elastically contact the yoke 22 to the rack bar 15, and at the rear of the spring 23, the yoke plug 24 supports the spring 23. ) Is provided with a yoke support 25 inserted and fastened. The yoke support 25 has a hollow cylindrical shape with one side open, and a groove having a circular cross section in which a thread is formed so that the yoke plug 24 can be inserted into the other side, which is not opened, has a through hole at the center thereof. Is formed. The yoke plug 24 is inserted into the groove of the yoke support 25 to be screwed and supports the spring 23 through the through hole, thereby generating a load by the elastic force in the arrow direction with respect to the yoke 22.

In addition, the yoke 22 has a cylindrical shape, and a stepped portion 27 in the circumferential direction is formed on the outer circumferential surface of the middle portion, and a rear end portion of the yoke 22 is formed in the circumferential protrusion 28. Correspondingly, the inner circumferential surface of the yoke support 25 is formed with a concave portion 26 including a free space for inserting the protrusion 28 of the yoke 22 to move a predetermined distance in the longitudinal direction of the yoke support 25. .

However, the conventional steering apparatus including the gearbox having the above structure has a rotational vibration (10 to 15㎐) on the steering wheel at a specific speed section (90 to 130 km), that is, shimmy (Shimmy: vibration in the direction of steering wheel rotation). ) Is generated. Simi generated during high-speed driving impairs steering stability, thereby causing anxiety for the driver and thus impairing safe driving.

Therefore, conventionally, a method of changing the natural frequency by increasing the operating frictional force of the mechanical components constituting the steering apparatus or by attaching a dynamic damper directly to the steering wheel to attenuate the shimi is used. However, these methods have limitations. Recently, there is a method of directly damping the vibration of the rack bar by installing an internal damper that reduces the flow rate of the fluid on the hydraulic line or by installing an external damper between the power cylinder and the rack bar. I use it.

However, according to the above device, it is possible to reduce the taste by attenuating and interrupting the transmission of vibration inputted back from the wheel to the steering wheel, but since the damping action is always performed in all speed ranges, the steering assist force by the power cylinder is reduced. As a result, the steering operation becomes difficult, and in particular, the steering wheel restoring force is reduced in the low speed region, so that a large amount of force is required for the steering wheel operation.

Accordingly, the present invention provides a steering system and a vibration reduction method using the vibration reduction device that can reduce the vibration caused by the imbalance of the automobile wheel by changing the yoke load of the steering apparatus as to solve the above-mentioned problems. Its purpose is to.

In addition, another object of the present invention is to reduce the vibration of the steering apparatus as described above to improve the NVH (Noise Vibration Harshness) performance, and furthermore, the steering system is provided with a vibration reduction device that can increase the marketability of the vehicle and vibration reduction using the same To provide a method.

Steering system provided with a vibration reducing device according to the present invention for achieving the above object, the vibration sensing means for detecting a change in the steering angle of the steering wheel to calculate the frequency, the actuator for pressing the yoke close to the rack bar and And a control unit for controlling the actuator for pressing the yoke by analyzing the frequency calculated by the vibration detecting unit.

In addition, the vibration reduction method using a steering system provided with a vibration reduction device according to the present invention, using the vibration sensing means for detecting a steering angle change of the steering wheel and calculating the frequency, and analyzing the calculated frequency and And changing the pressing force of the yoke by controlling the actuator according to the value analyzed by the controller.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this case, when it is determined that a detailed description of the known configuration and the function of the configuration of each component constituting the present invention may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, it should be noted that the same components among the components shown in the drawings have the same reference numerals as much as possible even though they are displayed on different drawings.

2 is a schematic diagram showing a steering system provided with a vibration reducing device according to the present invention, and FIG. 3 is a flowchart showing a vibration reduction method using a steering system provided with a vibration reducing device according to the present invention.

As shown in FIG. 2, the steering system provided with the vibration reducing device according to the present invention includes a rack and pinion type gear box 100 and a vibration sensing means 200 for detecting a frequency applied to a steering wheel (not shown). ), An actuator 400 for pressing the yoke 122 provided in the gear box 100, and a controller 300 for controlling the actuator 400. At this time, the rack and pinion type gearbox 100 is made of the same configuration and coupling structure as illustrated in the prior art bar, a detailed description thereof will be omitted.

The vibration detecting means 200 is provided in a steering wheel (not shown) of the steering system for a vehicle and detects a change in the steering angle when the vibration is applied to the steering wheel 210, and in the detection unit 210 Comprising a calculation unit 220 for calculating the frequency based on the change in the steering angle detected.

At this time, the frequency calculated by the vibration detecting means 200 is the required data for calculating the pressing force of the yoke 122 provided in the gear box 100, converted into a predetermined signal and transmitted to the control unit 300 Done.

The control unit 300 is for controlling the driving of the actuator 400 by analyzing the frequency signal received from the vibration detecting means 200. Here, the controller 300 determines whether the reference frequency is out of the range by comparing the received frequency, that is, the frequency detected and calculated by the sensing unit 210 and the calculating unit 220 with a reference frequency input in advance. Thereafter, when the calculated frequency deviates from the reference frequency, the kingpin moment is calculated using the calculated frequency, the rack load is calculated using the calculated kingpin moment value, and the calculated rack load is applied to the yoke 122 at that time. When the values do not coincide with the pressing force applied to the actuator, the pressing force of the yoke 122 is adjusted by controlling the actuator 400. In this case, when the calculated frequency is within the range of the reference frequency or the calculated rack load is equal to the pressing force applied to the yoke 122 at the corresponding time point, the actuator 400 is not driven and the pressing force at this time is maintained.

In addition, the actuator 400 is connected to the yoke plug 124 provided on one side of the yoke 122, as shown in FIG. 2, by pressing the yoke 122 by rotating the yoke plug 124. To be in close contact with the rack bar 113. Therefore, the actuator 400 is preferably a motor capable of rotating the yoke plug 124, and more preferably a stepping motor capable of adjusting the rotation angle and the rotation speed. That is, when the yoke plug 124 is rotated using a stepping motor, the pressing force of the yoke 122 may be finely adjusted.

Meanwhile, referring to FIGS. 2 and 3, a vibration reduction method using a steering system provided with a vibration reduction device configured as described above is as follows.

When vibration is applied to the steering wheel (not shown) while driving the vehicle, the sensing unit 210 provided therein detects a steering angle change of the steering wheel due to the vibration (S110), and calculates the detected change in the steering angle ( 220). The calculation unit 220 quantizes the received steering angle change and applies it to a previously input calculation formula, and when the frequency is calculated (S120) by the calculation formula, converts it to a predetermined signal and transmits it to the control unit 300. .

The received signal is analyzed by the controller 300. Looking at the analysis process, the calculated frequency is compared with a reference frequency input in advance to determine whether the reference frequency is out of the range (S130). Thereafter, when the calculated frequency is out of the reference frequency, the kingpin moment is calculated using the calculated frequency (S140), the rack load is calculated using the calculated kingpin moment value (S150), and the calculated rack load corresponds to the calculated rack load. When the value is not matched with the pressing force applied to the yoke 122 at a point in time (S160), the actuator 400 is controlled to change the pressing force of the yoke 122 (S170). In this case, when the calculated frequency is within the range of the reference frequency or the calculated rack load is equal to the pressing force applied to the yoke 122 at the corresponding time point, the actuator 400 is not driven and the pressing force at the time point is maintained (S180). Done.

As described above, the configuration, operation, and vibration reduction method using the same of the steering system provided with the vibration reduction device according to the preferred embodiment of the present invention are illustrated according to the above description and the drawings. Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the invention.

As described above, the steering system and the vibration reduction method using the vibration reduction device according to the present invention, by changing the load applied to the yoke of the steering apparatus according to the frequency can reduce the vibration caused by the imbalance of the automobile wheel. There is an advantage.

When the vibration of the steering apparatus is reduced as described above, it is possible to improve the vehicle's NVH (Noise Vibration Harshness) performance, and of course, it is possible to increase the merchandise of the vehicle.

Claims (6)

In a vehicle steering system comprising a yoke for pressing a rack bar under a constant load, Vibration sensing means for sensing a steering angle change of the steering wheel to calculate a frequency; An actuator for pressing the yoke to closely contact the rack bar; A control unit for controlling the actuator for pressing the yoke by analyzing the frequency calculated by the vibration detecting unit; Steering system provided with a vibration reducing device, characterized in that configured to include. The method according to claim 1, And a yoke plug for elastically supporting the yoke, wherein the actuator pressurizes the yoke plug. The method according to claim 1 or 2, The actuator is a steering system provided with a vibration reducing device, characterized in that the motor. The method according to claim 3, Steering system is provided with a vibration reducing device, characterized in that the motor is a stepping motor. In the vibration reduction method using a steering system provided with a vibration reduction device according to any one of claims 1 to 4, Calculating a frequency by detecting a steering angle change of a steering wheel using the vibration detecting means; Analyzing the calculated frequency; Changing the pressing force of the yoke by controlling the actuator according to the value analyzed by the controller; Vibration reduction method using a steering system provided with a vibration reduction device, characterized in that consisting of. The method according to claim 5, Analyzing the calculated frequency, Comparing the calculated frequency with a reference frequency; Calculating a kingpin moment value according to the frequency when the calculated frequency exceeds or falls below the reference frequency; Calculating a rack load using the calculated kingpin moment value; And Comparing the calculated rack load with the pressing force applied to the yoke at that time; Vibration reduction method using a steering system provided with a vibration reduction device, characterized in that consisting of.

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