KR20030016852A - Apparatus for variation of steering force in power steering system - Google Patents

Abstract

PURPOSE: A steering force varying device of a hydraulic power steering system is provided to manipulate steering force as wanted at both low and high speed by adjusting the steering force according to the traveling speed of a vehicle. CONSTITUTION: A gear linkage installed with a steering force varying device is composed of a housing(41), a torsion bar(45) installed in the center of the housing, a pinion shaft(46) covering the torsion bar and a valve(47) operated by the change of a moment according to the operation of the torsion bar to control a hydraulic flow. A first electromagnet(110) having magnetic force by an electronic control unit is fixed on the outside of the pinion shaft. A second electromagnet(120) having magnetic force against the first electromagnet is fixed on the valve. Polarity of one of the first and second electromagnets is changed according to the direction of electronic flow applied. Thereby, the steering force of the vehicle is provided according to the traveling speed.

Description

Steering force variable device of hydraulic power steering system {Apparatus for variation of steering force in power steering system}

The present invention relates to a device for varying steering power in a hydraulic power steering device, and more particularly, to a steering force variable device of a hydraulic power steering device to be able to vary the steering power in accordance with the running speed in the gearing package of the hydraulic power steering device. will be.

In general, a vehicle is provided with a steering device so that the driving direction of the vehicle can be arbitrarily changed while driving, and in recent years, the driving force of the steering wheel by the driver is doubled at low speed to add steering speed and convenience. In addition, hydraulic or electric power steering systems have been developed to reduce the operating force of the steering wheel and to add stability when steering at high speed.

1 illustrates a configuration of such a hydraulic power steering device. The power steering device includes a steering wheel 1 provided in a driver's seat and a steering column coupled to the steering wheel 1 so that a driver can operate the vehicle for changing a driving direction. 2) and the steering gear portion 5 from the oil pump (not shown) is coupled to the end of the universal joint (3) connected to the steering column (2) in accordance with the rotation of the steering column (2) by operating the handle (1) ) Is composed of a gearing kit (4) for controlling the oil supply to the left and right hydraulic cylinder (6).

The gearing package 4 surrounds the torsion bar 45 coupled with the housing 41, the universal joint 3 connected to the steering column 2, and the torsion bar 45 as shown in FIG. When the torsion bar 45 is twisted by the driver's handle 1, the moment the valve 47 operates as shown in Figs. 3A to 3C. The fluid introduced through the input port 42 of the housing 41 is supplied to the left and right cylinders 6 (see FIG. 1) through the left and right hydraulic cylinder ports 44. Reference numeral 43 is a return port through which the fluid is returned to the oil pump (not shown).

4A and 4B illustrate a process in which the flow of the fluid introduced into the valve is returned. The fluid introduced into the valve 47 includes the first return hole 48a, the second return hole 48b, and the third return. It returns through the hole 48c one by one.

However, the conventional gear steering kit 4 for the power steering device should be able to easily receive hydraulic assistance at low speeds, and should be carefully structured to receive hydraulic assistance at high speeds. Since any one of them was selected and the components were designed by focusing on it, there was a problem that the steering force was damaged in the opposite driving conditions.

Conventionally, in most cases, the steering force is made light at a low speed, which is a lot of force.

Therefore, due to the above problems, the steering wheel neutrality is weakened when driving in the first straight state, the handle is moved to the left and right when driving in the second straight driving, the handle restoring force is weak in the third small rotation, and the handle even with the fourth weak force The left and right rotates to impair the driving safety, and when the fifth wheel is restored after a sharp rotation, the steering wheel is moved to the left and right, and the driving stability is also lowered.

Accordingly, the present invention has been made in order to solve the above problems, the steering force variable device of the hydraulic power steering device to obtain a desired steering force at both low speed and high speed by adjusting the steering force according to the running speed of the vehicle. The purpose is to provide.

1 is a perspective view showing the configuration of a general hydraulic power steering device,

Figure 2 is a longitudinal cross-sectional view showing the main portion of the structure of the gear ring used in the conventional hydraulic power steering device,

3A to 3C are cross-sectional views showing the operating states of the torsion bar and the valve of the gearing kit of FIG. 2, respectively.

3a shows the torsion bar is in a neutral state,

3b shows that when the torsion bar is rotated to the left,

3C shows when the torsion bar is rotated to the right.

4A and 4B are views illustrating a process of returning a fluid flow introduced into an input port from the gearing kit of FIG. 1, respectively;

Figure 5 is a corresponding view of Figure 1, a cross-sectional view showing a structure of a gearing device to which the steering force variable device according to the present invention,

6 is a configuration diagram illustrating the steering force variable device of FIG. 5.

Explanation of Reference Symbols in Major Parts of Drawings

4-Gearing Kit 41-Housing

45-Torsion Bar 46-Pinion Shaft

47-Valve 110-First Electromagnet

120-second electromagnet 130-switching unit

ECU-Electronic Control Unit

In order to achieve the above object, the present invention, the torsion bar that rotates in accordance with the handle operation, the pinion shaft is installed to surround the torsion bar, and operates by the moment generated by the rotation of the torsion bar and the hydraulic flow In the configuration including a valve for controlling, the first electromagnet having a magnetic force is fixed to the outer side of the pinion shaft is applied by the operation of the electronic control unit, the valve is in contact with the first electromagnet The second electromagnet having a magnetic force by the electric force to be correspondingly fixed to be installed, and any one of the first electromagnet and the second electromagnet has a polarity is switched according to the applied oil direction, Provides an inertial variable device.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the steering force variable device of the power steering apparatus according to the present invention will be described in detail.

5 shows a gearing kit structure in which a steering force variable device according to the present invention is installed, and FIG. 6 shows a steering force variable device installed in the gearing kit of FIG. 5, wherein the gearing package 4 includes a housing 41 and the A torsion bar 45 built in the center of the housing 41, a pinion shaft 46 provided to surround the torsion bar 45, and an outer side of the pinion shaft 46 and an inner surface of the housing 41; A valve 47 positioned and actuated by a moment change according to the operation of the torsion bar 45, a first electromagnet 110 fixed to the upper portion of the pinion shaft 46 in the housing 41, and It is configured to include a second electromagnet 120 is fixed to the upper end of the valve 47 to correspond to the first electromagnet 110 in contact.

Here, the first electromagnet 110 and the second electromagnet 120 are composed of cores 111 and 121, and induction coils 112 and 122 to surround the cores 111 and 121, respectively. When current is applied to the 112 and 122, the magnets are generated in the cores 111 and 121 along the current flow direction.

Each of the induction coils 112 and 122 of the first electromagnet 110 and the second electromagnet 120 serves to switch the polarity of the electromagnet by applying power to them and changing the current direction flowing through any one of the induction coils. It is connected to the switching unit 130, which is controlled by the electronic control unit (ECU) according to the vehicle speed.

The steering force variable device of the present invention configured as described above operates as follows.

First, for better understanding, one side of the second electromagnet 120 provided on the valve 47 side is called the first electrode part # 1, and the other side is the second electrode part # 2, the pinion shaft 46. The first end of the first electromagnet 110 installed on the side facing the first electrode part # 1 is called a third electrode part # 3 and is opposite to the second electrode part # 2 opposite to the second electrode part # 3. Is referred to as a fourth electrode portion # 4.

First, the electric current applied to the first and second electromagnets 110 and 120 is set according to the speed of the vehicle before the vehicle is driven, and the polarity thereof is set. Then, when the steering wheel is operated while driving the vehicle, each electronic control unit (ECU) is operated. By detecting the vehicle speed at the operation of the switching unit 130, each electromagnet has a predetermined polarity, and the torsion bar 45 is rotated in the magnetic force environment of the electromagnet set as described above.

Subsequently, as in the related art, the valve 47 is operated by the moment generated by the rotation of the torsion bar 45 so that the fluid flows in a desired direction, thereby steering.

For example, the first electrode part # 1 and the third electrode part # 3 each have an N pole and an S pole, respectively, between 30 km / h in a stationary state, and the second electrode part # 2. ) And the fourth electrode part # 4 set the current directions applied to the induction coils 112 and 122 from the switching unit 130 to have different polarities of the S pole and the N pole, respectively.

That is, each of the electrode parts facing each other of the first electromagnet 110 and the second electromagnet 120 is set to have different polarities, and thus a pulling force is generated.

Accordingly, the force of the electromagnet is combined with the force of the torsion bar 45, so that steering can be performed with a small force at low speed.

In addition, at a speed between 30 km / h and 80 km / h, the power is turned off in the switching unit 130 so that the first electromagnet 110 and the second electromagnet 120 do not have magnetic properties.

That is, the valve 47 is operated only by the force of the torsion bar 45.

In addition, at a speed of 80 km / h or more, unlike the initial stage, only the polarity of the first electromagnet 110 is changed, that is, the first electrode part # 1 and the third electrode part # 3 each have the same N pole, The second electrode part # 2 and the fourth electrode part # 4 on the opposite side are set to have the same S pole.

As a result, each electromagnet has a pushing force, and the operation of the torsion bar 45 is prevented by the force of the electromagnet so as to prevent steering too lightly at high speed.

As described above, according to the present invention, since the operating moment of the torsion bar can be adjusted by adjusting the polarity of the electromagnet according to the traveling speed of the vehicle, the steering wheel neutrality is improved even when driving at high speed, and the steering wheel does not move from side to side. It also secures stable steering power while driving, improving driving stability.

In addition, the handle restoring force becomes clear even at a small rotation, and since the handle does not pass the neutral during the restoration after the rapid rotation, the phenomenon in which the handle plays from side to side does not occur.

Claims (2)

A torsion bar that rotates according to a handle operation, a pinion shaft installed to surround the torsion bar, and a valve which operates by a moment generated by the rotation of the torsion bar and controls a hydraulic flow, A first electromagnet having a magnetic force when the electric force is applied by the operation of the electronic control unit is fixedly installed on the outer side of the pinion shaft, and the valve has a magnetic force by the electric force so as to be in contact with the first electromagnet 2, the electromagnet is fixedly installed, and the steering force variable device of the hydraulic power steering device, characterized in that the polarity is switched according to any one of the first electromagnet and the second electromagnet is applied. The hydraulic power steering apparatus of claim 1, wherein the first electromagnet and the second electromagnet each comprise a pinion shaft and a core fixed to surround the outer surface of the valve, and an induction coil configured to surround the core. Steering power variable.