KR20030000864A - rack bar separation type steering system for an automotive vehicle - Google Patents

Abstract

PURPOSE: A steering apparatus for separating a rack bar in a vehicle is provided to improve freedom of design by dividing the rack bar into left and right parts and engaging with a driving pinion gear in mounting the steering gearbox. CONSTITUTION: A steering system is composed of a steering gearbox(4) having a driving pinion gear(13) rotating in applying operational force to a steering wheel; and an operating cylinder having a rack bar engaged with the driving pinion gear. The operating cylinder has a first operating cylinder(5') and a second operating cylinder(5'') including first and second rack bars(5a',5a'') engaged with the driving pinion gear. First and second rack gears(5b',5b'') are formed in rack bars, and engaged with the driving pinion gear. The freedom of design is improved by separating the operating cylinder into first and second operating cylinders and engaging rack gears with the driving pinion gear individually.

Description

Rack bar separation type steering system for an automotive vehicle

The present invention relates to a separate rack bar steering device of an automobile, and more particularly, by dividing a rack bar engaged with a drive pinion gear in a steering gear box to a left / right side and installing a steering gear box for a vehicle body. The present invention relates to a separate rack bar steering device of a vehicle that increases freedom of out and reduces the burden on the rigid design of the rack bar.

In general, a vehicle is provided with a steering device that enables the driver to change the direction of movement of the vehicle while driving. As an example of such a steering device, the steering wheel of the steering wheel is doubled by the driver during steering. The power steering device to add the convenience and convenience is as shown in FIG.

That is, the conventional power steering apparatus has a steering shaft (2) having a steering wheel (1) mounted on the upper end of the driver's steering operation, and a steering column (3) which surrounds the steering shaft (2) from the outside and is fixed to the vehicle body (3). ), A steering gear box 4 including a control valve mounted to the lower part of the steering shaft 2 to control the flow of hydraulic oil during steering, and a driving pinion gear provided at the lower end of the steering shaft 2; 2) and an operating cylinder (5) having an operating piston (shown in FIG. 2) which is engaged with the rotating shaft of the steering shaft (2) in a linear motion in a horizontal direction, and a crankshaft and a belt of the engine. An oil pump (6) for supplying hydraulic oil pressurized by the control valve of the steering gear box (4) when the steering is connected to operate by receiving power from it, a certain amount to supply the hydraulic oil to the oil pump (6) Consists of oil storage tank (7) for storing the working oil Lose.

In addition, between the steering gear box 4 including the control valve, the oil pump 6 and the oil storage tank 7, a supply line 8 (shown in solid line) and a recovery line 9 for supplying and recovering hydraulic oil, respectively, 9. ; Dotted lines) are disposed, and both ends of the operation cylinder 5 are exposed to the outside of the rack bar 5a connected to the internal working piston, and the rack bar 5a is connected to the front wheel side knuckle arms, respectively. The tie rod 10 is connected to push or pull the knuckle arm in the turning direction during steering.

In addition, the steering gear box 4 is provided with a pair of hydraulic lines 4a and 4b which communicate with pressure chambers formed on the left and right sides of the operating piston 5 in the interior of the operating cylinder 5, respectively.

Here, the specific configuration relationship between the steering gear box 4 and the operating cylinder 5 is shown in Figure 2, first, the steering gear box 4 is a torsion bar connected to the lower end of the steering shaft (2) (11) and the rotary sleeve 12 is provided on the outer periphery of the torsion bar 11 and linked with the rotation of the steering shaft (2) to change the flow path, and at the lower end of the torsion bar (11) It comprises a drive pinion gear 13 meshing with the rack gear (5b) formed on one side of the rack bar (5a) in the working cylinder (5).

In addition, the operation cylinder 5 is connected to the tie rod 10 at the left and right ends, and a rack bar 5a having a rack gear 5b formed at one side thereof, and mounted on the rack bar 5a. It comprises a working piston (5c) for partitioning the interior of the working cylinder (5) to the left / right pressure chamber.

In addition, the steering gear box (4) including the control valve is connected to the oil pump (6) and the supply line (8) as well as to the oil storage tank (7) via the recovery line (9). In addition, the left and right pressure chambers of the working cylinder 5 and the hydraulic lines 4a and 4b are connected to each other.

On the other hand, the engagement portion between the rack bar (5a) and the drive pinion gear 13 in the steering gear box (4) including the control valve, as shown in cross section in Figure 3, the steering gear box (4) In the housing H of the drive pinion gear 13 and the rack gear 5b formed on one side of the rack bar 5a of the operation cylinder 5 are meshed so as to intersect with each other, the steering gear box 4 The operating force according to the rotation of the drive pinion gear 13 is transmitted to the rack bar 5a through the rack gear 5b coupled thereto, and the tie rod 10 connected thereto according to the movement of the rack bar 5a. ) Will move to steer.

However, in the conventional steering apparatus configured as described above, since the rack gear 5b of the operation cylinder 5 engaged with the drive pinion gear 13 in the steering gear box 4 is formed integrally with the left / right sides, When the steering gear box 4 is installed in the vehicle body, the lay-out of the steering gear box 4 as well as the tie rod 10 coupled to the front end of the rack bar 5a should be considered at the same time.

That is, since the differential gear box of the transmission is protruded to the side where the drive pinion gear 13 is located in a normal passenger car, when the steering gear box 4 is positioned with a constant clearance therebetween, the rack gear ( Since the rack bar 5a forming 5b) must move as a whole, the selection of the lay-out for the actuating cylinder 5 including the rack bar 5a is dependent upon the lay-out of the steering gear box 4. Inevitably, the freedom of design is reduced in terms of effective utilization of space.

In addition, since the rack bar 5a of the operating cylinder 5 has a structure in which left and right sides are integrally formed around the driving pinion gear 13 of the steering gear box 4, the rack bar 5a is used during steering. Receives a compressive force on one side and a tensile force on the other side centering on the engagement portion with the drive pinion gear 13, in the case of a member that is simultaneously applied to the tensile force and the compressive force during operation, any one of the tensile force or the compressive force Since the axial stiffness should be improved when designing the shaft rather than the member to which only the load is applied, the post-treatment is required to improve the weight or other axial stiffness of the member.

In addition, the rack bar (5a) of the operating cylinder (5) can not only transmit the impact force input from one of the tires while driving the other side as it is, the transmission and vibration of the impact force to the various link members (members of the suspension arm system) connected thereto. There are disadvantages in terms of.

Accordingly, the present invention is conceived in view of the above, by dividing the rack bar to the left / right side to transfer the rotational force applied to the steering wheel during steering to the left / right wheels in a linear direction to the left / right side of the steering gear box. Separate rack bar steering system for automobiles by internally engaged with drive pinion gears to increase the degree of freedom in lay-out when installing the steering gear box for the vehicle body and to reduce the burden on axial rigidity design for the rack bar. The purpose is to provide.

The present invention for achieving the above object, the vehicle includes a steering gear box having a drive pinion gear that rotates by the steering operation force applied to the steering wheel, and an operation cylinder having a rack bar engaged with the drive pinion gear. In the steering apparatus, the actuating cylinder comprises a first actuating cylinder and a second actuating cylinder having first and second rack bars meshed with the drive pinion gear, respectively, and the first and second rack bars are steered. Characterized in that the first and second rack gear to be spaced up and down spaced with the drive pinion gear of the gear box.

1 is a perspective view showing the configuration of a general type steering device.

FIG. 2 is a cross-sectional view illustrating a configuration relationship between a steering gear box including a control valve and an operation cylinder in the steering apparatus illustrated in FIG. 1.

FIG. 3 is a cross-sectional view showing the engagement portion between the rack bar and the drive pinion gear in the steering gear box shown in FIG.

Figure 4 is a perspective view showing the configuration of a separate rack bar steering device according to the present invention.

FIG. 5 is a cross-sectional view showing the engagement portion between the rack bar and the drive pinion gear in the steering gear box shown in FIG. 4; FIG.

Figure 6 is a schematic diagram for illustrating a state in which the rack bar detachable steering apparatus according to the present invention can be installed on the vehicle body.

<Description of Symbols for Main Parts of Drawings>

1-steering wheel 2-steering shaft

3-steering column 4-steering gearbox

5-operating cylinder 5'-first actuating cylinder

5 "-2nd working cylinder 5a ', 5a"-1st, 2nd rack bar

5b ', 5b "-1st and 2nd rack gear 10-Tie rod

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

Figure 4 is a perspective view showing the configuration of a separate rack bar steering device according to the present invention, Figure 5 is a cross-sectional view showing the engagement portion between the rack bar and the drive pinion gear in the steering gear box shown in Figure 4, Figure 6 Is a schematic diagram for illustrating a state in which the rack bar detachable steering apparatus according to the present invention can be installed on a vehicle body, the same reference region as in FIGS. 1 to 3 showing the configuration of a conventional steering apparatus for a detailed description of the present invention. The same reference numerals will be given together.

The present invention, as shown in the figure, a steering shaft (2) equipped with a steering wheel (1) for the steering operation of the driver, and a steering column (3) surrounding the steering shaft (2) and fixed to the vehicle body A steering gear box 4 mounted at a lower portion of the steering shaft 2 and including a control valve configured to control the flow of hydraulic oil during steering; and a driving pinion gear 13 provided at a lower end of the steering shaft 2; ) And a working cylinder (5) having a working piston for linear movement in the left and right directions in accordance with the rotational movement of the steering shaft (2), and the steering gear box for reducing the steering force during steering by receiving power from the engine. An oil pump (6) for supplying hydraulic oil pressurized by the control valve (4) and an oil storage tank (7) for storing a certain amount of hydraulic oil to supply hydraulic oil to the oil pump (6).

In addition, between the steering gear box 4 including the control valve, the oil pump 6 and the oil storage tank 7, a supply line 8 and a recovery line 9 for supplying and recovering hydraulic oil are disposed. At both ends of the actuating cylinder 5, the rack bar 5a connected to the actuating piston is exposed to the outside, and the rack bar 5a is connected to the front wheel side knuckle arms, respectively, in a turning direction during steering. A tie rod 10 is connected to push or pull the knuckle arm to rotate.

Here, the operating cylinder (5) is composed of a first operating cylinder (5 ') and a second operating cylinder (5 ") of the type independently separated to the left / right around the steering gear box (4). The first actuating cylinder 5 'on one side and the second actuating cylinder 5 "on the other side are engaged with the driving pinion gear 13 in the steering gear box 4, respectively.

That is, as shown in FIG. 5, the first rack gear 5b "formed in the first rack bar 5a 'in the first actuating cylinder 5' and the inside of the second actuating cylinder 5". The second rack gears 5b "formed on the second rack bar 5a" are respectively spaced apart from each other on the drive pinion gear 13 positioned in the housing H of the steering gear box 4, and are individually engaged. The first rack bar 5a 'of the first actuated cylinder 5' and the second rack bar 5a "of the second actuated cylinder 5" as the drive pinion gear 13 rotates. The respective linear movements in the same direction to move the tie rods 10 connected to each so that steering can be made.

In addition, the steering gear box 4 has two pairs of hydraulic pressures which are respectively communicated to the pressure chambers formed at the left and right sides of the operating pistons, respectively, inside the first operating cylinder 5 'and the second operating cylinder 5 ". Pipe lines 4a and 4b are provided.

Accordingly, as described above, operation cylinders 5 engaged with the steering gear box 4 including the control valve and converting the rotational force applied to the steering wheel 1 in the linear direction during steering are respectively left / right. When the first actuating cylinder 5 'and the second actuating cylinder 5 "are separated, the first and second as shown in FIG. 6 when the steering gear box 4 is installed on the vehicle body. Although the positions of the tie rods 10 coupled to the front end portions of the rack bars 5a 'and 5a "are fixed, the steering gear box 4 can be freely set in the front and rear directions of the vehicle body. The freedom of design for the gearbox 4 can be increased.

That is, the actuating cylinder (5) is composed of a first actuating cylinder (5 ') and a second actuating cylinder (5 ") of the left and right, and they are respectively driven with the drive pinion gear (13) of the steering gear box (4). Since the structures are individually engaged, the degree of freedom of arrangement with respect to the steering gear box 4 is increased as described above.

Meanwhile, as described above, the first rack bar 5a 'and the second operation cylinder 5 of the first and second operating cylinders 5' on the left and right sides are independently of the driving pinion gear 13 of the steering gear box 4, respectively. When the second rack bar 5a of ") is engaged, the first rack of the left / right first actuating cylinder 5 'around the driving pinion gear 13 of the steering gear box 4 during steering. Since the bar 5a 'and the second rack bar 5a "of the second actuating cylinder 5" receive only the axial load of any one of the compressive force and the tensile force according to the steering direction, the rack bar (when steering conventionally) In 5a), the load on the axial rigidity can be lessened by the fact that the compressive and tensile forces do not act simultaneously.

In addition, the first and second rack bars 5a 'and 5a "of the actuating cylinder 5 have a structure in which left and right sides are separated with respect to the drive pinion gear 13 of the steering gear box 4. Since the impact force input from one tire T is not transferred to the other side as it is while driving, the impact force is transmitted to the various link members (members of the suspension arm system) and vibrations connected to the tire T installed on the opposite side. It is advantageous from the side.

As described above, according to the rack bar detachable steering apparatus of the present invention, an operating cylinder engaged with the driving pinion gear 13 of the steering gear box 4 to impart movement force to the tie rod 10 during steering ( 5) is separated into the left / right first actuating cylinder 5 'and the second actuating cylinder 5 ", and the first and second rack bars 5a' and 5a" are respectively formed of first, As the second rack gears 5b 'and 5b "are individually engaged with the drive pinion gear 13, the degree of freedom of design for the installation of the steering gear box 4 is increased, as well as the first and second racks during steering. Since the operating force transmitted to the bars 5a 'and 5a "is selected as either tensile or compressive force, respectively, the burden on consideration of axial rigidity in designing the first and second rack bars 5a' and 5a" can be reduced. do.

Claims (2)

Steering gear box 4 having a drive pinion gear 13 that rotates by a steering operation force applied to the steering wheel 1, and an operating cylinder 5 having a rack bar 5a meshed with the drive pinion gear 13. In the steering device of a vehicle comprising: The actuating cylinder (5) is a first actuating cylinder (5 ') and a second actuating cylinder (5) having first and second rack bars (5a', 5a "), respectively engaged with the drive pinion gear (13). Rack bar separate steering device of the vehicle, characterized in that consisting of "). The method of claim 1, The first and second rack bars 5a 'and 5a "are first and second rack gears 5b' and 5b" which are spaced up and down and engaged with the drive pinion gear 13 of the steering gear box 4, respectively. Rack bar separate steering device of the vehicle, characterized in that formed.