KR20020040217A - Screw and gear type variable steering system for use in a car - Google Patents

Abstract

PURPOSE: A threaded gear type variable steering system for a vehicle is provided to reduce the radius of rotation of a vehicle by maximizing the steering angle of front wheels when a snow chain is not installed. CONSTITUTION: A threaded gear type variable steering system for a vehicle comprises a threaded gear(20) installed on one end of a steering shaft(12) and rotating with the steering shaft, a reducing gear(30) for reducing torque by driven via the threaded gear and having a fixing protrusion(31), a stopper(40) for stopping the rotation of the fixing protrusion, and a drive unit for selectively placing the stopper on the movement path of the fixing protrusion. When a snow chain is not installed in a vehicle, the stopper is not placed on the movement path of the fixing protrusion. Thus, a steering wheel(11) is operated without restraint. Therefore, the steering angle is extended while the radius of rotation of the vehicle is reduced.

Description

SCREW AND GEAR TYPE VARIABLE STEERING SYSTEM FOR USE IN A CAR}

The present invention relates to a steering system of a vehicle, and more particularly, it is possible to reduce the radius of rotation of a vehicle as needed by enabling the variable amount of rotation of a steering shaft that transmits a driver's steering control force to a rotational movement. The present invention relates to a variable steering device.

The steering device is a device that allows the driver's direction to be changed arbitrarily as the driver intends. A steering wheel and steering axis which transmits the driver's operating force to the rotary motion, and a steering gear that converts the operating force from the rotary motion to the linear motion It is composed of tie rods that transmit the operating force to the wheels, and ball and nut types and rack and pinion types are generally used according to the steering gear type.

1 shows a rack & pinion type steering mechanism, which engages the pinion 3 formed on the outer circumference of the steering shaft 2 with the rack 4 inside the gearbox 1 to linearly rotate the shaft 2. After the conversion to the rack (4) and the ball joint (6) through the tie rods (5) connected to the wheel (not shown) is structured to be.

Such a conventional steering apparatus is configured such that when the steering wheel is rotated to the maximum, steering is performed within a range in which the tire does not cause interference in the wheel house. In particular, the maximum steering angle of the wheel is limited in case of installing a snow chain in winter, so that the wheel house has some clearance even when the wheel movement is maximized.

Therefore, when the steering angle range of the wheel is increased by using the clearance inside the wheel house, the radius of rotation of the vehicle can be reduced. In the conventional steering apparatus, the steering of the wheel is made in consideration of the case where the snow chain is mounted as described above. The movement range of the rack is fixed so that the operation is made, thereby limiting the rotation range of the steering wheel, which is not suitable for realizing this.

The present invention is to solve the conventional problems as described above, the present invention enables to steer the wheel using the maximum amount of free space in the wheel house, while the amount of rotation of the steering shaft depending on whether the chain is installed It is an object of the present invention to provide a variable steering device that can reduce the radius of rotation of a vehicle in a general situation in which no chain is mounted by being able to adjust it variably.

The present invention for achieving the above object, the screw gear is provided on one end of the steering shaft, the gear is driven by the screw gear to reduce the rotational force, one side of the reduction gear having a locking projection, and a stopper to block the rotation of the locking projection And drive means for selectively positioning the stopper on the movement path of the locking projection.

According to the present invention, when the snow chain is mounted in winter, the stopper is placed on the rotation path of the locking projection to limit the rotation of the steering shaft within a certain range, so that the steering amount of the wheel is applied in the same way as a general vehicle.

On the contrary, when the snow chain is not mounted, the stopper is not positioned on the rotation path of the locking protrusion, thereby eliminating the rotational limitation of the steering shaft and increasing the steering angle of the wheel. In this case, since the wheels can be steered in the maximum range in which the interference does not occur in the wheel house, the radius of rotation of the vehicle can be reduced by that much.

1 is a cross-sectional view showing a conventional rack & pinion type steering mechanism,

2 is a block diagram of a screw gear type variable steering apparatus according to the present invention,

3 is an operating state diagram of the variable steering apparatus according to the present invention;

4 is another embodiment of the present invention.

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

11: Steering wheel 12: Steering shaft

20: screw gear 30: reduction gear

31: projection (of reduction gear) 40: stopper

50: operation lever (51): hinge

52: spring 53: eccentric cam (cam)

54: motor 55: rotational shaft (of the motor)

Such a characteristic configuration of the present invention and its effects will be more apparent through the detailed description of the embodiments with reference to the accompanying drawings.

Figure 2 shows a screw gear type variable steering apparatus according to the present invention, wherein the driver's steering force applied to the steering wheel 11 is transmitted to the rotational movement of the steering shaft 12 and in the gear box (not shown). Is converted into linear motion of the rack and transmitted to the wheels through tie rods.

The screw gear type variable steering apparatus according to the present invention variably adjusts the amount of rotation of the steering shaft 12 so that when the chain is mounted, the wheel can be steered within a range that does not cause interference in the wheel house, and the chain If it is not installed, it can reduce the turning radius of the vehicle by increasing the steering amount of the wheel by utilizing the free space in the wheel house.

Therefore, the configuration is, as shown in Figure 2, is installed on the steering shaft 12, the same as the screw gear 20 and the screw gear 20, driven in accordance with the screw gear 20 to reduce the rotational force, the locking projection on one side Reduction gear 30 having a 31, a stopper 40 for blocking the rotation of the locking projection 31, and drive means for selectively positioning the stopper 40 on the rotation path of the locking projection 31 Is done.

Here, the screw gear 20 rotates at the same speed as the steering shaft 12, the reduction gear 30 is driven to the screw gear 20 to reduce the rotational force to 3.5: 1. In order to do this, both sides are coupled in a worm gear or contacted in a general manner, while maintaining the circumferential ratio of both contact surfaces at 1: 3.5.

The projection 31 provided on the reduction gear 30 is preferably positioned to be adjacent to the circumferential surface of the reduction gear 30, and is installed so as to be located on the opposite side to the stopper 40 in a state in which the wheel is placed in a straight position. Accordingly, when the reduction gear 30 is driven by the screw gear 20 to rotate, the reduction gear 30 reduces the rotation speed of the screw gear 20 to 3.5: 1 as described above, so that the steering shaft 12 When the screw gear 20 rotates 1.75 laps together, the reduction gear 30 and the protrusion 31 rotate at a ratio of approximately 0.5 laps. At this time, as shown in Figure 2, when the stopper 40 is located on the movement path of the projection 31, the projection 31 is limited to the rotation by the stopper 40, the steering wheel 11 is No further rotation.

In addition, when the stopper 40 is not positioned on the movement path of the protrusion 31 as shown in FIG. 3, the rotation of the protrusion 31 is not limited, so that the steering wheel 11 can continuously rotate. .

On the other hand, the configuration of the drive means for selectively positioning the stopper 40 on the rotation path of the projection 31 is as follows.

First, in the case of FIGS. 2 and 3, the driving means is fixed by the hinge 51, and the stopper 40 is mounted at one end by the spring 52, and the stopper centered around the hinge 51. It consists of the eccentric cam 53 which contacts the operation lever 50 on the opposite side to 40, and the motor 54 which drives the eccentric cam 53. As shown in FIG. Accordingly, when the motor 54 is driven, the eccentric cam 53 rotates to rotate the operating lever 50 about the hinge 51, and the stopper 40 is positioned on the movement path of the protrusion 31. Or vice versa, it is separated from the movement path of the projection 31.

When the snow chain is mounted on the wheel in winter, when the stopper 40 is placed on the moving path of the protrusion 31, the reduction gear 30 is restricted because the locking protrusion 31 is restricted by the stopper 40. As a result, the rotation of the steering wheel 11 is limited. At this time, the steering angle of the wheel is the same as the setting value of the general vehicle, it is possible to steer the wheel within the range that does not cause interference in the wheel house with the snow chain mounted.

In the case of not mounting the snow chain, the steering wheel 11 is not limited to rotation because the stopper 40 is not positioned on the movement path of the protrusion 31, in which case the wheel is free space inside the first wheel house. Considering this, steering is possible up to the set range, and as a result, the turning radius of the vehicle is reduced.

On the other hand, Figure 4 shows the drive means as another embodiment, the operating lever 40 is directly screwed with the rotating shaft 55 of the motor 54, the other configuration and operation is the same.

As described above, the screw gear type variable steering apparatus according to the present invention is provided with a screw gear installed on a steering shaft, and a driving gear for selectively driving a stop gear and a stopper for limiting the rotation of the reduction gear, which follow thereto. It is possible to adjust the amount of rotation of the steering wheel variably. When the snow chain is not mounted, the rotation radius of the vehicle is reduced by securing the maximum steering angle of the front wheel by using the free space in the wheel house. do.

Claims (4)

In a vehicle steering device in which the steering operation force of the driver is transmitted to the rotational movement of the steering shaft, A screw gear 20 installed at one end of the steering shaft 12 and rotating together with the steering shaft 12, A reduction gear 30 having a locking protrusion 31 on one side thereof to reduce the rotational force by following the screw gear 20; A stopper 40 for blocking rotation of the locking protrusion 31 in response to the locking protrusion 31; And a driving means for selectively positioning the stopper (40) on the movement path of the locking projection (31). The method of claim 1, The driving means is fixed to the hinge 51, the stopper 40 is mounted at one end by the spring 52, the operating lever 50 and the hinge 51 around the opposite side of the stopper 40 Eccentric cam (53) in contact with the operation lever 50, and a motor-driven variable steering apparatus, characterized in that consisting of a motor (54) for driving the eccentric cam (53). The method of claim 1, The driving means is fixed to the hinge 51, the stopper 40 is mounted at one end by the spring 52, the operating lever 50 and the hinge 51 around the opposite side of the stopper 40 Vehicle control gear steering device, characterized in that the operating lever 50 and the rotating shaft 55 is made of a screwed motor (54). The method of claim 1, The reduction gear 30 is a vehicle screw gear type variable steering device, characterized in that for reducing the rotation of the screw gear (20) to 3.5: 1.