KR100646397B1 - Low hiss noise input shaft and hydraulic power steering apparatus having the same - Google Patents

Abstract

An input shaft and a hydraulic pressure power auxiliary steering apparatus using the same are provided to reduce the discomfort sensation of a driver and simplify the working process by forming two return holes formed at the input shaft and lowering the hiss noise under the threshold while traveling. An input shaft(210) installed at a hydraulic pressure power auxiliary steering apparatus is composed of two return holes(250) formed at the inlet shaft. The two return holes are placed to face each other on the center shaft of the input shaft. The hiss noise is reduced through the increment of the minimum pressure applied at the gear box in the initial steering by forming the two return holes formed at the input shaft.

Description

Low Hiss Noise Input Shaft and Hydraulic Power Steering Apparatus Having The Same}

1 is a schematic configuration diagram showing a general configuration of a hydraulic power assist steering device;

2 is a longitudinal sectional view of the control valve housing and the gear box of the hydraulic power assist steering device;

Figure 3a is a block diagram of a hydraulic power assist steering device including the AA 'cross-sectional view of Figure 2 when the steering wheel neutral;

3b is a configuration diagram of a hydraulic power assist steering device including the sectional view taken along line A-A 'of FIG.

Figure 3c is a block diagram of a hydraulic power assist steering device including the AA 'cross-sectional view of Figure 2 when the steering wheel left,

4 is a cross-sectional view taken along line B-B 'of FIG.

5 is a cross-sectional view taken along line BB ′ of FIG. 2 according to the present invention.

<Description of Symbols for Main Parts of Drawings>

100: steering wheel 105: steering shaft

110: control valve housing 115: gear box

120: pinion gear 125: rack gear

130: rack housing 135: piston

140: tie rod 145: knuckle arm

150: wheel 160: power steering oil tank

165: engine 170: recovery flow path

175: supply flow path 180: left flow path

185: right side Euro 190: rack bar

195: sealing portion 200: torsion bar

210: input shaft 220: pinion shaft

230: valve body 250: return hole

The present invention relates to an input shaft and a hydraulic power assisted steering apparatus having the same. More specifically, the present invention relates to an input shaft and a hydraulic power assisted steering apparatus having the same, which reduce noise by increasing the minimum pressure applied to the gearbox during initial steering by forming two return holes formed in the input shaft.

In general, a vehicle steering device is a device that transmits the rotational force of the steering shaft according to the steering wheel to the steering device so that the driver can turn the vehicle in a desired direction, and is largely divided into an electric power assist steering device and a hydraulic power assist steering device. .

The electric power assisted steering device uses the steering power of the steering wheel according to the driving speed of the vehicle to reduce the steering power at the time of stopping or at low speed, and the steering power at the high speed to provide the driver with high speed stability. It is a kind of steering device.

On the other hand, the hydraulic power assist steering device drives the power steering pump using the driving force of the engine, and selectively injects the power steering oil output from the power steering pump into the cylinder to lighten the steering force at the time of stopping or at low speed, and at high speed It is a kind of steering device that provides the driver with high speed and heavy driving force.

1 is a schematic configuration diagram showing a general configuration of a hydraulic power assist steering device.

The hydraulic power assist steering device transfers the power energy generated by the engine 165 to the power steering pump 155 to suck the power steering oil stored in the power steering oil tank 160 through the suction flow path 173, and then supply the flow path. Supply to the control valve housing 110 through the (175).

When the components are divided into a front end and a rear end based on the control valve housing 110, the front end is provided through a supply flow path 175 and a supply flow path 175 which become flow paths of the power steering oil supplied from the power steering pump 155. A power steering pump 155 for supplying power steering oil to the recovery flow path 170 and the supply flow path 175 in which the supplied power steering oil is recovered, an engine 165 for providing driving power to the power steering pump 155, and power A suction flow path 173 through which the steering pump 155 sucks the power steering oil, one side is connected to the recovery flow path 170, and the other side is connected to the suction flow path 173, and the recovered power steering oil is suction path 173. And a power steering oil tank 160 that temporarily stays before being injected into the tank.

Meanwhile, the rear end guides the left and right linear motions of the rack bar 190 to the outer circumferential surface of the rack bar 190, and the inner housing surface of the rack bar 190 when the rack housing 130 and the rack bar 190 move left and right linearly around the rack bar 190. Fixed in the outer circumferential surface and the outer circumferential surface of the ring housing piston 180 and the relative piston movement of the ring housing 130, the rack housing 130 in the longitudinal direction of the rack housing 130 to the left and right both sides of the rack housing 130 It is fixed to the rack bar 190 to close the rack bar 190 when the rack bar 190 moves in a linear motion to prevent the leakage of the power steering oil while sealing the rack bar 190, the piston 180 in the rack housing 130 The left cylinder (A) and the right cylinder (B) is formed between the left and right sealing portions 195 around the center. The left cylinder A is connected to the left flow passage 180 and the right cylinder B is connected to the right flow passage 185.

2 is a longitudinal sectional view of the control valve housing and gear box of the hydraulic power assisted steering.

The gear box 115 has a structure for converting the rotational motion of the pinion gear 120 into a linear motion of the rack bar 190, and the inside of the input shaft 210 is hollow and is connected to one side of the steering shaft 105. . One side of the torsion bar 200 is inserted and fixed into the inner hollow of the input shaft 210 is interlocked with the input shaft 210 connected to the steering shaft 105, the other side is connected to the pinion shaft 220 and the pinion shaft 220 Form a pinion gear 120 meshed with the rack bar 190.

When the driver rotates the steering wheel 100, the input shaft 210, the torsion bar 200, the pinion shaft 220 and the pinion gear 120 has a structure to rotate. The torsion bar 200 is a kind of spring that generates a torsion caused by the rotation difference between the steering shaft 105 and the pinion shaft 220. The torsion bar 200 has a function of changing the flow path of the control valve housing 110 by the torsion bar 200. Has

The outer circumferential surface of the input shaft 210 is wrapped with a hollow valve body 230, the valve body 230 rotates in conjunction with the pinion shaft 220. That is, the pinion shaft 220, the pinion gear 120 and the valve body 230 has a structure to rotate in conjunction. In addition, a control valve housing 110 is wrapped around an outer circumferential surface of the valve body 230, and the control valve housing 110 includes a supply flow passage 175, a recovery flow passage 170, a left flow passage 180, and a right flow passage 185. ) Is formed. When the driver does not operate the steering wheel 100, the power steering oil entering through the supply flow path 175 exits through the recovery flow path 170, but the steering shaft 105 is rotated and twisted to the torsion bar 200. In this case, the power steering oil supplied to the supply flow path 175 is changed to the flow path caused by the difference in rotation between the outer circumferential surface of the input shaft 210 and the inner circumferential surface of the valve body 230. Is injected into.

Due to the friction force generated between the wheel 150 and the road surface, the pinion gear 120 rotates by applying a rotational force greater than the static friction force. However, when the driver rotates the steering wheel 100 to the right, the input shaft 210 also rotates to the right accordingly. However, when the pinion gear 120 does not rotate, the torsion bar 200 is twisted. As a result, the valve body 230 is connected to the pinion shaft 220 and is not rotated so as to be connected to the steering shaft 105 to rotate only one end of the input shaft 210 and the torsion bar 200. Accordingly, a difference in rotation occurs between the input shaft 210 and the valve body 230 by the torsion of the torsion bar 200, and a step difference between the groove formed between the inner circumferential surface of the valve body 230 and the outer circumferential surface of the input shaft 210 occurs. .

Figure 3a is a block diagram of a hydraulic power assist steering device including the AA 'cross-sectional view of Figure 2 when the steering wheel neutral. When the steering device is not operated, there is no difference in rotation between the outer circumferential surface of the input shaft 210 and the inner circumferential surface of the valve body 230 so that the power steering oil introduced through the supply passage 175 is formed on the inner circumferential surface of the valve body 230. It moves in the longitudinal direction of the torsion bar 200 through the return hole 250 to the recovery flow path.

3B is a configuration diagram of the hydraulic power assist steering device including the AA ′ cross-sectional view of FIG. 2 when the steering wheel is rotated to the right. The rotation difference between the input shaft 210 and the valve body 230 is rotated by rotating the steering wheel 100 to the right. When generated, the power steering oil introduced through the supply flow passage 175 is supplied to the right flow passage 185 through the groove formed on the inner circumferential surface of the valve body 230 and the groove formed on the outer circumferential surface of the input shaft 210. Therefore, the rack bar 190 is moved to the left by the pressure of the power steering oil supplied to the right cylinder (B) and the wheel is steered to the right. At this time, the power steering oil in the left cylinder (A) is introduced into the valve body 230 through the left flow passage 180 and eventually circulated to the power steering oil tank 160 through the recovery flow passage.

3C is a configuration diagram of the hydraulic power assist steering device including the AA ′ cross-sectional view of FIG. 2 when the steering wheel is turned to the left. The rotation difference between the input shaft 210 and the valve body 230 is rotated by rotating the steering wheel 100 to the left. When generated, the power steering oil introduced through the supply flow passage 175 is supplied to the left flow passage 180 through the groove formed on the inner circumferential surface of the valve body 230 and the groove formed on the outer circumferential surface of the input shaft 210. Therefore, the rack bar 190 is moved to the right by the pressure of the power steering oil supplied to the left cylinder (A) and the wheel is steered to the left. At this time, the power steering oil in the right cylinder (B) flows into the valve body 230 through the right flow passage 180 and is eventually circulated to the power steering oil tank 160 through the recovery flow passage.

4 is a cross-sectional view taken along line BB ′ of FIG. 2.

In the conventional input shaft 210, four circular return holes 250 radially penetrating from the inside of the input shaft 210 to the outside were formed around the central axis of the torsion bar 200 provided in the input shaft 210. .

Power steering oil which enters the supply flow path 175 by the pressure generated from the power steering pump 155, selectively delivers hydraulic pressure to the left or right cylinder according to the rotation direction of the valve body 230 and the input shaft 210, and is recovered. Exits through the return hole 250 formed in the input shaft 210 and returns to the power steering oil tank 160 through the recovery flow path 170. At this time, while the power steering oil moves due to the rotation of the input shaft 210, the flow path cross-sectional area between the valve body 230 and the input shaft 210 is continuously repeated to expand and contract. A change in the cross-sectional area of the flow path causes a change in the flow velocity, which generates strong noise as the power steering oil moves, and this noise causes the driver to stop when steering or parking while the engine noise is relatively low. There was a problem that makes you feel uncomfortable.

In order to solve this problem, an object of the present invention is to reduce the noise by increasing the minimum pressure applied to the gearbox during initial steering by forming the number of two return holes formed in the input shaft.

In order to achieve the above object, the present invention, in the hydraulic power assist steering device for changing the driving direction of the vehicle as the driver's will, the steering wheel, the rotation of the steering wheel receives the rotation torque for steering operation from the driver A steering shaft that transmits torque, an input shaft connected to the steering shaft, a rack bar having a rack gear for converting rotational torque input from the input shaft into linear motion, a gear box including pinion gears, a rack housing penetrating the gear box and enclosing the rack bar, Link mechanism including tie rods and ball joints to connect the knuckles for transmitting the linear motion of the rack bar to the wheels, power steering pump to generate pressure in the power steering oil and to circulate the power steering oil, Control valve housing to control input and output, control valve housing A hydraulic power assisted steering device comprising a cylinder for applying the action force of the rack bar according to the operation of the rack and a piston for reciprocating the left and right reciprocating motion in combination with the rack bar inside the cylinder, wherein two return holes are formed in the input shaft. to provide.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

Figure 5 is a cross-sectional view B-B 'in accordance with the present invention.

By reducing the return hole 250, which was four conventional, to two, the noise is reduced by increasing the initial minimum pressure applied to the gear box 115 during steering.

The two return holes 250 are formed to face each other based on the central axis of the torsion bar 200 provided in the input shaft 210.

As a result of experimenting with the conventional input shaft and the steering apparatus using the input shaft according to the present invention, the hydraulic power assisted steering apparatus using the conventional input shaft was a noise level slightly higher than 40 dB and the hydraulic power assist steering apparatus using the input shaft according to the present invention. Compared with the conventional method, the noise is reduced by 2-3 dB.

When the noise is lowered below the 40 dB threshold, the driver hardly recognizes the noise generated during steering, and the discomfort felt by the driver is completely eliminated.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, the number of return holes formed in the input shaft is reduced to two to reduce the noise generated during steering to be less than the threshold, thereby eliminating the discomfort felt by the driver during steering and simplifying the work process to reduce the manufacturing cost. There is.

Claims (2)

In the input shaft provided in the hydraulic power assist steering device, The input shaft provided in the hydraulic power assist steering device, characterized in that there are two return holes formed in the input shaft. The method of claim 1, The two return holes are provided in the hydraulic power assisted steering apparatus, characterized in that the opposite to each other about the central axis of the input shaft.

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