KR100836041B1 - Steering Characteristics Control Device Using Stiffness Control of Torsion Bar - Google Patents

Abstract

The present invention relates to a steering characteristic control apparatus using the rigidity control of the torsion bar, and in particular, is connected to the upper end of the torsion bar to vary the length of the torsion bar to vary the effective length of the torsion bar, and transmits the rotational force of the steering wheel to the torsion bar and; A motor for driving the length variable stage up and down; An ECU for forward and backward driving of the motor according to a vehicle driving speed detected by a vehicle speed sensor to control a steering characteristic by varying a length of a torsion bar; By adjusting the length of the torsion bar according to the driving speed of the vehicle, the torsion bar's torsional rigidity is increased or decreased, and when the vehicle is traveling at a low speed, the steering force is increased so that the driver can operate the steering wheel smoothly. Steering characteristics are reduced by reducing the steering force when the vehicle is traveling at high speed, and the steering wheel is heavy, and the steering characteristics using the stiffness control of the torsion bar to simplify the structure of the product and expect the effect of productivity improvement and manufacturing cost reduction. It relates to a control device.

Torsion bar, steering wheel, steering characteristics, steering force, variable length stage, motor, ECU,

Description

Steering property control device using stiffness control of torsion bar

1 is a view showing a conventional torsion bar.

2 is a cross-sectional view taken along the line A-A of FIG.

3 is a view showing a steering characteristic control apparatus using the stiffness control of the torsion bar of the present invention.

4 is a cross-sectional view taken along the line B-B in FIG. 3.

5 is a cross-sectional view taken along the line C-C in FIG.

6 is a view for explaining the technical background of the present invention.

Explanation of symbols for main parts of the drawings

1: inner shaft, 2: torsion bar,

3: coupling, 4: pinion gear,

5; Press-in groove, 6: outer sleeve,

10: variable length, 11: ECU,

12: vehicle speed sensor, 13: extension,

20: variable shaft, 21: serration,

22: groove, 23: groove,

24: projection, 25: gear portion,

26: drive gear, 27: motor,

28: outer shaft, 29: connection,

30: receptacle,

The present invention relates to a steering characteristic control apparatus using stiffness control of the torsion bar, and in particular, by varying the length of the torsion bar according to the traveling speed of the vehicle, increasing or reducing the torsional rigidity of the torsion bar, thereby driving the vehicle at low speed. When the vehicle is driving at high speed, the steering wheel is heavier and the steering wheel is heavier, and the structure of the product is simplified to improve productivity and reduce manufacturing cost. A steering characteristic control apparatus using stiffness control of a torsion bar to expect an effect.

1 and 2 show the installation state of the conventional torsion bar.

1 shows a valve assembly of a steering gear box, and a torsion bar 2 is inserted into the inner shaft 1, and the upper part of the inner shaft 1 and the upper part of the torsion bar 2 are pins. Coupled to, the coupling portion 3 formed in the lower portion of the torsion bar (2) is fitted into the indentation groove 5 formed on the upper portion of the pinion gear (4) for supplying the steering force to the wheel is fixed as shown in FIG.

In addition, an outer sleeve is linked with a pin at an upper portion of the pinion gear 4.

In the related art, when the steering torque is supplied to the inner shaft 1 and the torsion bar 2 by the driver's steering wheel operation, the torsion bar 2 is twisted and the outer sleeve 6 and the inner shaft 1 are rotated. A rotational displacement proportional to the steering torque is generated, and the rotational displacement is supplied to the wheel through the pinion gear 4 to control the running direction of the vehicle.

As described above, the torsion bar 2 is a very important component having a function of transmitting the steering force of the steering wheel to the pinion gear 4, and when the stiffness coefficient of the torsion bar 2 is increased, the valve for the steering force is increased. The relative rotational displacement amount of the shaft is small, and the generated pressure is small.

As a result, the assist force becomes small, the steering wheel steering force becomes heavy, and conversely, the lower the stiffness coefficient of the torsion bar, the lighter steering force characteristics are obtained.

The ideal steering characteristics of the power steering system are light and soft characteristics at the stop and low speed, rigidity at the middle and high speeds, and solid (heavy) characteristics, and a steering characteristic control device for providing such steering characteristics is provided. .

The conventional steering characteristic control device is difficult to satisfy the two kinds of contradictory requirements as described above. If the light characteristics at low speed are important, the high speed region is unstable, and if the importance at high speed is emphasized, the steering force at the low speed becomes heavy. It is being designed at the optimum point of both.

In recent years, ECPS is a steering characteristic control device that detects vehicle speed and steering angle to operate steering characteristics in the most ideal state in order to satisfy steering steering force corresponding to driving conditions. It is divided into control method. However, the ECPS has a problem in that the operation is complicated and the cost is excessive for the performance effect.

Therefore, the present invention for solving the above problems is connected to the variable length of the upper end of the torsion bar to vary the effective length of the torsion bar, the length variable stage for transmitting the rotational force of the steering wheel to the torsion bar; A motor for driving the length variable stage up and down; An ECU for forward and backward driving of the motor according to a vehicle driving speed detected by a vehicle speed sensor to control a steering characteristic by varying a length of a torsion bar; By adjusting the length of the torsion bar according to the driving speed of the vehicle, the torsion bar's torsional rigidity is increased or decreased, and when the vehicle is traveling at a low speed, the steering force is increased so that the driver can operate the steering wheel smoothly. The stiffness of the torsion bar allows the steering wheel to be heavier by reducing the steering force when the vehicle is traveling at high speeds, and by simplifying the structure of the product compared to the conventional ECPS, improving productivity and reducing manufacturing cost. An object of the present invention is to provide a steering characteristic control apparatus using control.

The present invention for achieving the above object,

According to claim 2,

The torsion bar is inserted into the inner shaft, and the engaging portion formed at the lower portion of the torsion bar is fitted and fixed in the press-in groove formed in the upper portion of the pinion gear for supplying the steering force to the wheel.

A variable length end connected to the upper end of the torsion bar to vary the effective length of the torsion bar and transmitting the rotational force of the steering wheel to the torsion bar;

A motor for driving the length variable stage up and down;

An ECU for forward and backward driving of the motor according to a vehicle driving speed detected by a vehicle speed sensor so that an effective length of a torsion bar is changed to control steering characteristics;

Consists of including

delete

The length variable stage,

A length variable shaft having an insertion groove formed at a lower side of the center, the upper portion of the torsion bar is fitted into an insertion groove of the length variable shaft, a gear portion is formed at a side portion of the length variable shaft, and the gear portion is formed on a rotating shaft of the motor. It is characterized in that it is formed to engage the driven drive gear.

According to claim 3,

An outer shaft having an accommodating portion for accommodating an upper portion of the variable shaft is fitted to the upper side of the variable shaft, and coupled to the upper portion of the outer shaft to form a connection for connecting with a steering wheel. It is characterized in that the upper portion of the variable-shaft shaft and the receiving portion of the outer shaft to be engaged by forming a ration.

According to claim 4,

The upper part of the inner shaft is characterized in that the expansion portion for inserting the variable length shaft to move up and down.

According to claim 5,

A plurality of protrusions protrude in the longitudinal direction at the upper end of the torsion bar, and a groove corresponding to the protrusion is formed at the lower end of the variable shaft.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, FIGS. 3 to 6.

In the description of the present invention, the same components as in the prior art will be denoted by the same reference numerals to avoid redundant description.

According to the drawings, the present invention is largely composed of a length variable stage 10 and a control means.

The length variable stage 10 is connected to move up and down on the upper end of the torsion bar 2 to vary the effective length of the torsion bar 2, and to transmit the rotational force of the steering wheel to the torsion bar 2,

A longitudinally adjustable shaft 20 having an insertion groove 22 formed below the center is coupled to the upper portion of the torsion bar 2 by being inserted into the insertion groove 22 of the variable shaft 20.

In addition, the gear part 25 is formed on the side surface of the variable shaft 20, and the gear part 25 is engaged with the drive gear 26 held by the rotational shaft of the motor 27 laying down the gear part 25. An outer shaft 28 having an accommodating portion 30 accommodating an upper portion of the variable shaft 20 is fitted to the upper side of the variable shaft 20, and connected to a steering wheel at an upper portion of the outer shaft 28. The connecting portion 29 is formed.

The serration 21 is formed on the variable shaft 20 so that the upper portion of the variable shaft 20 and the receiving portion of the outer shaft 28 are engaged with each other, so that the steering rotational power supplied from the steering wheel is the outer shaft. It is to be transmitted to the variable-length shaft 20 through the (28).

In addition, the upper portion of the inner shaft 1 is formed with an extension 13 for inserting the variable length shaft 20 that moves up and down so that the variable length shaft 20 can be moved up and down smoothly. A plurality of protrusions 24 protrude from the upper end of the bar 2 in the longitudinal direction, and grooves 23 corresponding to the protrusions 24 are formed at the lower end of the variable shaft 20 to form the protrusions 24 and the protrusions 24. By the coupling of the groove 23, the rotational force of the variable-length shaft 20 can be transmitted to the torsion bar 2 as it is.

On the other hand, the control means constituting the present invention,

The drive gear 26 is driven on the axis of rotation of the motor 27 to drive the variable length 10 up and down, and the drive gear 26 of the gear 25 of the variable-length shaft 20 By coupling to the so that the longitudinally variable shaft 20 is moved up and down by the forward and reverse rotation of the motor 27,

The motor 27 is configured to forward and backward drive by a control signal output from the ECU 11 according to the vehicle running speed detected by the vehicle speed sensor 12.

The present invention is to allow the stiffness to be controlled by varying the effective length of the torsion bar 2 by using the variable length of the variable stage 10, so that the steering force of the steering wheel is increased or decreased, the technical background of FIG. This is described first with reference to.

In general, the torsional rigidity of a cylinder is influenced by the material, cross-sectional area, and length of the cylinder.

If the cylinder is of the same material, the torsional stiffness is proportional to the cross-sectional area of the cylinder and inversely proportional to its length.

That is, if the cylinder of the same length as shown in Fig. 6 (a), the larger the cross-sectional area is more torsional rigidity, and if the cylinder having the same cross-sectional area as shown in Fig. 6 (b), the torsional rigidity is larger Will lose.

The present invention is to vary the effective length of the torsion bar (2) by using the above principle to change the steering force of the steering wheel according to the vehicle running speed.

The operation of the present invention will be described as follows.

When the vehicle travels at a low speed, the ECU 11 drives the motor 27 according to the low speed information detected by the vehicle speed sensor 12 so that the variable-shaft shaft 20 rises.

As the length-variable shaft 20 rises, the effective length of the torsion bar 2 increases, and the torsional rigidity of the torsion bar 2 decreases relatively, thereby increasing the relative rotational displacement of the valve shaft. As the pressure increases, the assist force is increased, allowing the driver to operate the steering wheel lightly.

On the contrary, when the vehicle travels at a high speed, the ECU 11 reversely drives the motor 27 according to the high speed information detected by the vehicle speed sensor 12 so that the variable shaft 20 descends.

When the length-variable shaft 20 is lowered, the effective length of the torsion bar 2 is shortened, and the torsional rigidity of the torsion bar 2 is relatively increased, whereby the relative rotational displacement of the valve shaft is reduced, thereby generating pressure. As it decreases, the assist force is reduced, causing the driver to operate the steering wheel heavily.

As described above, the present invention includes a variable length end connected to the top of the torsion bar to vary the effective length of the torsion bar and transmitting the rotational force of the steering wheel to the torsion bar; A motor for driving the length variable stage up and down; An ECU for forward and backward driving of the motor according to a vehicle driving speed detected by a vehicle speed sensor to control a steering characteristic by varying a length of a torsion bar; By adjusting the length of the torsion bar according to the driving speed of the vehicle, the torsion bar's torsional rigidity is increased or decreased, and when the vehicle is traveling at a low speed, the steering force is increased so that the driver can operate the steering wheel smoothly. The stiffness of the torsion bar allows the steering wheel to be heavier by reducing the steering force when the vehicle is traveling at high speeds, and by simplifying the structure of the product compared to the conventional ECPS, improving productivity and reducing manufacturing cost. The effect of providing a steering characteristic control apparatus using control can be expected.

Claims (5)

delete The torsion bar 2 is inserted into the inner shaft 1, and the engaging portion 3 formed at the lower portion of the torsion bar 2 is press-fitted on the upper portion of the pinion gear 4 which supplies the steering force to the wheel. In the thing inserted in the groove 5 and fixed, A variable length stage 10 connected to the upper end of the torsion bar 2 to change the effective length of the torsion bar 2 and transmitting the rotational force of the steering wheel to the torsion bar 2; A motor 27 for driving the length variable stage 10 up and down; An ECU 11 for driving the motor 27 forward and backward according to the vehicle driving speed detected by the vehicle speed sensor 12 so that the effective length of the torsion bar 2 is variable to control steering characteristics; Consists of including The length variable stage 10, It is provided with a variable length shaft 20 having an insertion groove 22 formed in the center, the upper portion of the torsion bar 2 is fitted into the insertion groove 22 of the variable length shaft 20, the variable length shaft Stiffness control of the torsion bar, characterized in that the gear portion 25 is formed on the side of the (20), the gear portion 25 is formed to engage the drive gear 26 stored on the rotating shaft of the motor (27). Steering characteristic control device using. The method of claim 2, An outer shaft 28 having an accommodating portion 30 for accommodating an upper portion of the variable length shaft 20 is fitted to the upper side of the variable length shaft 20, and a steering wheel is mounted on the upper portion of the outer shaft 28. It forms a connecting portion 29 to be connected, the serration 21 is formed on the upper side of the variable shaft 20 so that the upper portion of the variable shaft 20 and the receiving portion of the outer shaft 28 is engaged. Steering characteristic control device using the stiffness control of the torsion bar. The method of claim 2, Steering characteristics control device using the rigid control of the torsion bar, characterized in that the upper portion of the inner shaft (1) is formed with an extension (13) for inserting the variable length shaft (20) moving up and down. The method of claim 2, A plurality of protrusions 24 protrude from the upper end of the torsion bar 2 in the longitudinal direction, and a groove 23 corresponding to the protrusion 24 is formed at the lower end of the variable shaft 20. Steering characteristic control device using the stiffness control of the torsion bar.

Images