KR100998563B1 - Power steering device - Google Patents

Abstract

The present invention relates to a power steering apparatus provided with a reaction mechanism for generating a reaction force against the ground resistance of the tire, the gist of the technical configuration of the power steering apparatus provided with a reaction mechanism, the reaction mechanism unit 180 The V groove 182 is provided in the circumferential direction on the top surface of the valve body 115, and is fixed as a pin (P) on the input shaft 112 of the end of the valve body 115 and the V in the radial direction The guide plate 184 in which the same number of communication holes 185 are drilled at positions facing the grooves 182 in the vertical direction, and is inserted into and supported in the communication holes 185 of the guide plate 184. The ball 186 located in the V-groove of the valve body and the lifting and lowering on the input shaft 112 above the guide plate 184 to operate in the axial direction by the introduced hydraulic pressure to press the ball onto the V-groove. Consists of a piston (188) The point is to lose.

According to the present invention of such a configuration, when the torsion occurs between the valve body and the input shaft by the ball, the friction friction is induced between each other, thereby preventing the sliding due to the displacement to minimize the effect on the hysteresis (Hysteresis) There is.

Input shaft, valve body, reaction structure, ball, piston

Description

Power steering device

1 is a cross-sectional view showing a hydraulic control valve mechanism of a conventional power steering device.

Figure 2 is a schematic diagram showing the overall configuration of the power steering apparatus according to the present invention.

Figure 3 is an enlarged cross-sectional view showing the main portion of the reaction mechanism mechanism according to FIG.

Figure 4 is an exploded perspective view showing a separated state of FIG.

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

<Description of Signs of Major Parts of Drawings>

110 Hydraulic valve 111 Housing

112 Input shaft 113 Pinion

114 Torsion Bar 115 Valve Body

120 ... flow control valve 122 ... solenoid

180 ... Reaction Mechanism 182 ... V Groove

184 ... guide plate 185 ... communication hole

186 Ball 188 Piston

190.Reaction Cylinder

The present invention relates to a power steering apparatus, and more particularly, by installing a reaction force mechanism using rolling friction of the ball to the upper end of the valve body of the input shaft in which the valve body is fitted to control the relative displacement against the twist between the input shaft and the valve body Thus, when relative displacement occurs between the input shaft and the valve body due to the tire ground resistance, it prevents sliding friction between them to minimize the influence on hysteresis and to reduce the installation space with a simple structure. It relates to a steering device.

In general, the power steering device is to double the steering power by using a separate power, a hydraulic pump driven by the engine's power, a power cylinder having a rack bar and a piston therein so as to be operated by the hydraulic pressure transmitted therefrom, and a return It consists of a reservoir tank for storing the supplied hydraulic pressure and resupplying it with the hydraulic pump.

In particular, the middle one side of the power cylinder is operated by a steering wheel to install a hydraulic control valve to switch the flow of hydraulic pressure that is moved between the hydraulic pump and the power cylinder, one side thereof is operated in the up and down direction by the solenoid A flow rate control valve for adjusting the opening degree of the flow path between the hydraulic control valve and the spool is provided.

1 is a cross-sectional view showing a hydraulic control valve mechanism of such a conventional power steering device. As shown therein, the input shaft 12 is rotatably inserted into the upper portion of the housing 11 forming the hydraulic control valve 10, and the pinion 13 is disposed below the input shaft 12. The torsion bar 14 is installed between the input shaft 12 and the pinion 13.

And, the valve body 15 is installed on the outer side of the input shaft 12 to adjust the opening degree of the hydraulic pressure moved through them according to the rotation angle therebetween, for this purpose, one side of the outer peripheral surface of the hydraulic control valve 10 A pump (not shown) is connected, and the power cylinder 20 is connected to the other side of the hydraulic control valve 10.

In addition, one side of the hydraulic control valve 10 is connected to the flow path between the input shaft 12 and the valve body 15 is provided with a flow control valve 30 having a spool 31 to adjust the opening degree therebetween. On the lower side, a solenoid 32 connected to a controller (not shown) is provided to operate the spool 31 in the axial direction.

On the other hand, a reaction force cylinder 41 penetrates radially so as to communicate with an input shaft 12 installed therein at an upper end side of the pinion 13, and a reaction force piston 42 is installed inside the reaction force cylinder 41. At the tip of the reaction force piston 42, a rounded protrusion is integrally formed to be in close contact with a groove formed in the input shaft 12.

At this time, the rear side of the reaction cylinder 41 is connected to the flow control valve 30 side, the reaction force piston 42 and the input shaft 12 in the reaction cylinder 41 by the hydraulic pressure supplied in accordance with the operation of the flow control valve 30 ) By adjusting the degree of close contact between the pinion (13) and the input shaft (12), thereby adjusting the flow path between the input shaft (12) and the valve body (15), and eventually the power cylinder (20) Adjust the hydraulic pressure supplied to).

However, such a conventional power steering device has a projection which is in close contact with the input shaft 12 at the end of the reaction force piston 42 to generate a reaction force against the torsion as integrally formed as described above. When a torsion of a predetermined width occurs between the valve body 15 and the input shaft 12 as the ground resistance, the projection of the reaction force piston 42 causes the sliding friction on the groove of the input shaft 12, and thus the valve body 15 Since the amount of rotational displacement due to torsion is controlled between the input shaft 12 and the input shaft 12, reaction force loss is concerned and accurate control of the rotational displacement becomes difficult. As a result, the hysteresis of the steering resistance related to the vehicle speed may be affected, resulting in inadequate power generation in the driving state, resulting in a decrease in steering feeling, and induction of centering of the steering wheel.

In addition, since the reaction force cylinder is formed in the radial direction of the input shaft in order to form a section in which the reaction force piston 42 is operated, there is a problem that the installation space is enlarged in the radial direction to increase the volume of the device.

The present invention has been made in view of the above-described conventional problems, and provided to enable the piston to be elevated on the input shaft above the valve body, and between the piston and the valve body through the ball through the input shaft and the valve body By configuring the relative displacement in the mixed state of rolling friction and sliding friction, the reaction force loss is reduced when the relative displacement occurs between the input shaft and the valve body due to the tire ground resistance. It is an object of the present invention to provide a power steering apparatus which can minimize the hysteresis and reduce the volume of the apparatus because the reaction mechanism is provided in the space above the valve body in the form of an axial start.

As a technical means for achieving the above object, the present invention provides a power steering apparatus having a reaction force mechanism provided to regulate their relative displacement between the input shaft and the valve body by the hydraulic pressure supplied according to the operation of the flow control valve. Wherein, the reaction mechanism unit, the V groove provided in the circumferential direction on the valve body upper end surface, is fixed as a pin on the input shaft of the end of the valve body and in a position facing the V groove in the radial direction in the vertical direction The ball is located in the V groove of the valve body in a state where the same number of communication holes are drilled, the ball is positioned in the communication hole of the guide plate, and is supported in the axial direction by the introduced hydraulic pressure. Consisting of a piston that is pushed up and down on an input shaft above the guide plate to press the The power steering apparatus of the gong by maryeonham.

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

2 is a view showing a power steering apparatus according to the present invention. As shown therein, the input shaft 112 is installed inside the housing 111 of the hydraulic control valve 110, and the pinion 113 is installed at the lower end thereof, and the input shaft 112 and the pinion 113 The torsion bar 114 is installed inside.

At this time, the input shaft 112 and the pinion 113 which receives the rotational force therefrom are connected to have a predetermined rotational direction play, and the torsion bar 114 therein is provided to be twistable, and the input shaft 112. The valve body 115 is installed on the outside of the c) to adjust the opening amount of the flow path hole through which the hydraulic pressure moves according to the relative displacement with the input shaft.

In addition, a hydraulic pump 130 for supplying hydraulic pressure to the hydraulic control valve 110 is connected to one side of the outer circumferential surface of the hydraulic control valve 110, and a power cylinder 140 is connected to the other side, and another reservoir tank is connected to the other side. 150 is connected.

In addition, one side of the hydraulic control valve 110 is connected to the flow path between the input shaft 112 and the valve body 115 is provided with a flow control valve 120 having a spool 121 to adjust the flow rate is input thereto On the lower side, a solenoid 122 operated according to the instruction of the controller 160 is installed to operate the spool 121 in the axial direction.

In this case, the controller 160 is connected to the torque sensor 161, the speed sensor 162 and the angular speed sensor 163 to receive the current status of the vehicle detected by the electric signal, accordingly to the solenoid 122 A signal is sent to control this, which is identical to the conventional configuration.

On the other hand, between the input shaft 112 and the valve body 115 is operated as a hydraulic pressure transmitted through the flow control valve 120, the relative displacement due to the ground resistance of the tire between the input shaft 112 and the valve body 115 When a reaction force mechanism 180 for controlling such a displacement amount is provided.

In other words, when the driver rotates the steering wheel and the input shaft 112 is rotated, the torsion bar 114 is generated between the input shaft 112 and the valve body 115 via the torsion bar 114. The applied reaction force mechanism 180 is installed above the valve body 115 and is a hydraulic pressure supplied from the flow control valve 120 to directly determine a relative displacement, that is, a torsion angle between the input shaft 112 and the valve body 115. By controlling the opening degree of the flow path between the input shaft 112 and the valve body 115 according to the vehicle speed.

As shown in FIGS. 3 to 4, the reaction mechanism unit 180 includes a V-groove 182 provided in the circumferential direction on the upper surface of the valve body 115, and an input shaft 112 at the end of the valve body 115. The guide plate 184 is fixed as a pin (P) on the radial direction and the same number of communication holes (185) perforated at the position facing the V-groove 182 in the vertical direction, and the guide The ball 186 positioned in the V groove of the valve body in the state of being inserted into and supported in the communication hole 185 of the plate 184 and axially operated by the introduced hydraulic pressure to press the ball onto the V groove. It consists of a piston (188) fitted to be elevated on the input shaft 112 above the guide plate (184).

That is, the V groove 182 is formed in the circumferential direction of the upper surface rim of the valve body 115 to be fitted to the interruption of the input shaft 112 at equal intervals, and thus the valve body provided with the V groove 182 ( The guide plate 184 is fixed as the pin P on the input shaft 112 at the end (see FIG. 5).

At this time, the same number of communication holes 185 are drilled on the guide plate 184 at the same position as the position of forming the V groove 182 of the valve body 115, and the balls 186 are inserted into the guide plate 184. The lower end of the ball 186 supported by the guide plate 184 is positioned on the V-groove 182 to control the reaction force by rolling the left and right sides along the inclined surface of the V-groove 182 when displacement occurs. .

That is, the guide plate 184 prevents the detachment of the ball 186 installed on the V-groove and serves to support the ball 186 so that the ball 186 can roll along the inclined surface of the V-groove 182.

In addition, a piston 188 that pushes the ball 186 in close contact with the V groove 182 is fitted to the upper side of the ball 186 so that lifting and lowering is possible on the input shaft 112. The inner and outer diameters of the piston 188 are provided. The oil seal structure such as O-ring is provided to prevent the leakage of hydraulic pressure.

That is, the piston 188 is in the state in which the inner end is fitted to lift on the input shaft 112, the outer diameter is in close contact with the inner diameter of the housing 111 to form one cylinder 190 on the upper side of the piston after assembly, The cylinder 190 is a reaction force cylinder for controlling the reaction force to the displacement amount between the valve body 115 and the input shaft 112 according to the vehicle speed by adjusting the degree of pressurization of the ball (188).

Meanwhile, as shown in FIG. 2, a flow path is formed in the housing 111 to supply hydraulic pressure from the flow control valve 120 to the reaction force cylinder 190, and the housing 111 has a flow control valve 120. Of course it is connected to).

In the power steering apparatus of the present invention configured as described above, when there is no operation of the steering wheel, the hydraulic pressure supplied from the hydraulic pump 130 passes through the valve body 115 and the input shaft 112 and then returns to the reservoir tank 150. Both sides of the power cylinder 140 may maintain the driving state of the vehicle by maintaining an equilibrium state.

On the other hand, when the driver rotates the steering wheel in the left to right direction, the torsion bar 114 is twisted because the ground resistance is applied to the tire, and a relative displacement occurs between the valve body 115 and the input shaft 112. A flow path is opened. As a result, the hydraulic pressure supplied from the hydraulic pump 130 is moved to one side of the power cylinder 140 via the valve body 115 to generate the back force.

In detail, when the vehicle runs at a low speed, the reaction force mechanism 180 may be operated in a state of operating the steering wheel as described above rather than the hydraulic pressure transmitted to the valve body 115 under the control of the flow control valve 120 by the controller 160. The oil pressure delivered to the side becomes low. Accordingly, the reaction force mechanism 180 has no influence on the input shaft 112 so that the input shaft 112 and the valve body 115 are twisted by the torsion bar 114 to increase the opening area of the flow path. The hydraulic movement amount to the power cylinder 140 is increased through the input shaft 112 and the valve body 115 to generate a back force, so that the driver can feel a light steering feeling.

On the contrary, when the vehicle runs at a high speed, the solenoid 122 is operated by the controller 160 that detects the high speed, and as a result, the spool 121 of the flow control valve 120 is moved in the axial direction so that the reaction mechanism unit 180 is moved. The hydraulic pressure supplied to the side becomes high.

Therefore, when the hydraulic pressure is supplied to the reaction mechanism unit 180 in this way, the pressure in the reaction force cylinder 190 is increased to push the piston 188 and the ball 186 supported under the piston 188 downward. The ball 188 is strongly adhered to the V-groove 182 of the input shaft 112 by the pressing force of the piston 189 to generate a reaction force that resists relative displacement due to torsion. Due to this reaction force, the displacement amount between the input shaft 112 and the pinion 113 is reduced and the opening area of the flow path is reduced, so that the hydraulic pressure input to the power cylinder 140 is lowered, resulting in a heavy steering feeling and induction of centering of the steering wheel after steering. Will be improved.

In particular, in the present invention, when the relative displacement of the input shaft 112 and the valve body 115 due to the twist caused by the ball 186 interposed between the piston 188 and the V groove 182 of the input shaft 112. Since the rolling motion is induced between them, it is possible to minimize the influence on the hysteresis due to the sliding friction generated in the existing reaction mechanism structure to generate the optimum power according to the vehicle speed.

As described above, according to the power steering apparatus of the present invention, when the twist occurs between the valve body and the input shaft by the ball, rolling friction is induced between each other, thereby preventing slippage due to displacement, thereby minimizing the influence on hysteresis. You can do it. As a result, it is possible to improve the steering feeling by generating the optimum power according to the vehicle speed.

In addition, the reaction mechanism is controlled by the piston acting in the axial direction the reaction force generation degree, there is an effect that the installation space according to the reaction mechanism installation is reduced, thereby reducing the volume of the device.

Claims (1)

An input shaft installed inside the housing to receive an external rotational force, a pinion connected to the input shaft to receive a rotational force, and having a relative displacement with respect to the input shaft during steering, a torsion bar installed to be twistable in the pinion and the input shaft; A valve body installed outside the input shaft so that relative displacement occurs with the pinion as the torsion bar is twisted, a flow control valve installed at one side of the housing to control hydraulic pressure supplied between the valve body and the input shaft, and the flow control valve In the power steering apparatus having a reaction force mechanism portion provided to regulate their relative displacement between the input shaft and the pinion by the hydraulic pressure supplied in accordance with the operation of, The reaction mechanism unit 180 is fixed as a pin (P) on the V groove 182 provided in the circumferential direction on the upper surface of the valve body 115, and the input shaft 112 of the end of the valve body 115. In the radial direction, a guide plate 184 in which the same number of communication holes 185 are drilled at a position facing the V groove 182 in the vertical direction, and a communication hole 185 of the guide plate 184. Ball 186 positioned in the V-groove of the valve body in the state of being held inside and supported, and an input shaft on the upper side of the guide plate 184 to press the ball onto the V-groove by operating in the axial direction by the introduced hydraulic pressure. Power steering device, characterized in that consisting of a piston (188) fitted to be elevated on (112).

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