KR100991990B1 - Piston structure of steering gear box - Google Patents

Abstract

The present invention relates to a piston structure of a hydraulic power steering device gearbox, which forms a groove in a piston fixed on a rack bar of a gearbox to induce the inflow of hydraulic pressure, thereby securing a piston ring fixed to the piston by the introduced hydraulic pressure. The purpose is to reduce the impact noise of the piston ring according to the change in the steering direction by pressing the pressure.

In the technical configuration of the present invention, the O-ring groove 40 is provided in the radially central recess of the piston 4 fixedly installed on the rack bar 3, and the O-ring 42 for oil sealing is provided in the O-ring groove 40. In the gearbox assembly piston structure in which the piston ring 44 is sequentially inserted, the piston 4 is pressurized by hydraulic pressure to the piston ring 44 coupled to the O-ring groove 40 to remove the noise caused by the piston operation. A plurality of grooves 46 are formed in the circumferential direction of both side edges of the inner ring of the o-ring groove 40.

Piston, O-Ring Groove, Piston Ring, Groove, Gap

Description

Steering gearbox piston structure

1 is a cross-sectional view showing the configuration of the gearbox assembly of the hydraulic steering device.

Figure 2 is a cross-sectional view showing an installation state of the steering gearbox piston applied to the present invention.

3 is a perspective view of a piston according to the present invention;

* Description of Signs of Major Parts of Drawings *

2.cylinder housing

3.Rack Bar

4 ... piston

40 ... O-Ring Groove

42 ... O-Ring

44.Piston Ring

46 ... Home

The present invention relates to a piston structure of a hydraulic power steering device gearbox, which in particular forms a groove in the piston fixed on the rack bar in the gearbox to induce the inflow of hydraulic pressure, thereby fixing to the piston by the inflow hydraulic pressure. The present invention relates to a steering mechanism gearbox piston structure capable of pressing the piston ring to reduce impact noise of the piston ring due to a change in steering direction of the handle.

In general, a vehicle steering device is a device that enables the driver to turn the vehicle in a desired direction by transmitting the rotational force of the steering shaft according to the steering of the steering wheel. In recent years, steering by steering the steering wheel using hydraulic pressure is provided. Hydraulic steering devices (power steering systems) are commonly installed in vehicles to generate steering lightening the steering wheel.

Such a hydraulic power steering system includes an operation mechanism including a steering wheel (handle) provided in a driver's seat, a link mechanism connected to the operation mechanism to transmit a rotational force, and a speed reduction of the input rotational force connected to the link mechanism. It is configured to include a gearbox assembly for changing the wheel by converting the rotational movement of the operating mechanism to linear movement.

Figure 1 is a schematic cross-sectional view showing the gearbox assembly of the hydraulic steering device having the above configuration, as can be seen through the figure, the gearbox assembly is provided with a cylinder housing (2) at the lower side, and It has an external shape as the valve housing 1 provided on the upper end to be coupled.

First, an input shaft 10, a torsion bar (not shown), and a pinion shaft (not shown) are installed in the valve housing 1 and connected to a steering shaft to receive rotational torque. A valve (not shown) is provided for controlling the flow direction of the high pressure oil supplied from the pump.

Next, in the cylinder housing 2, a rack bar 3 engaged with the pinion shaft of the valve housing 1 and converting the rotational movement into a horizontal movement is built in the longitudinal direction, and the center outer circumference of the rack bar 3 is provided. The piston 4 is provided in the associative form to form a pair of power cylinders 2a and 2b on both left and right sides of the piston 4.

At this time, the O-ring groove 40 is formed in the radially outer circumferential center portion of the piston so that the O-ring 42 and the piston ring 44 are sequentially inserted into the O-ring groove 40, and thus the inner diameter of the cylinder 2 is formed. In close contact with (see partial enlarged view of FIG. 1).

Therefore, the gearbox assembly having such a configuration acts on the piston 4 when the hydraulic pressure flows in one of the left and right power cylinders around the piston 4 in the cylinder housing 2 and the pressure increases. Due to the pressure difference between the left and right power cylinder, the rack bar (3) is sliding in the lower direction from the high pressure to assist the steering wheel steering force and at the same time to change the wheel.

However, when the piston 4 in the cylinder slides left and right due to the pressure difference of the pair of power cylinder portions as described above, the piston ring 44 fitted on the piston is conventionally the inner diameter of the cylinder housing 2. As the piston moves in close contact with the piston ring 44, the piston ring 44 is compressed and compressed to form a gap g with the inner wall of the O-ring groove, and the piston 4 according to the left and right steering of the handle due to this gap. The piston ring 44 flows in the O-ring groove 40 in accordance with the change in the direction of travel) and hits the inner wall of the O-ring groove 40 to cause a noise noise.

The present invention has been made in order to improve the above problems of the prior art, the object of which is to form a plurality of grooves (Groove) in the circumferential direction of the inner wall of the piston O-ring groove so that the hydraulic pressure introduced into the power cylinder inside the grooves In order to pressurize the piston ring to one side, it is to provide a steering gearbox piston structure that can effectively reduce the impact noise of the piston ring according to the steering direction change of the handle.

As a technical means for achieving the above object, the present invention, the O-ring groove is provided in the radially central recess of the piston fixedly installed on the rack bar O-ring and piston ring for the oil sealing in the O-ring groove sequentially fitted gearbox In the assembly piston structure, a plurality of grooves are formed in the circumferential direction of the inner wall edge of the O-ring groove of the piston so as to pressurize the piston ring coupled to the O-ring groove as hydraulic pressure to remove noise due to the piston operation. By providing a steering gearbox piston structure.

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

In the present embodiment, the same reference numerals and names will be used for the same parts as those shown in the related art.

Figure 2 is a cross-sectional view of the installation state of the steering gearbox piston applied to the present invention, Figure 3 is a perspective view showing a piston according to the present invention.

Referring to FIG. 2, a rack bar 3 for extending the rotational movement of the steering shaft into a horizontal motion is long in the cylinder housing 2, and a piston 4 is formed on the center outer circumference of the rack bar 3. It is provided to form a pair of power cylinders 2a and 2b on both the left and right sides of the piston 4.

At this time, the O-ring groove 40 is formed in the radially outer circumferential center portion of the piston 4 so that the O-ring 42 and the piston ring 44 for oil sealing are sequentially formed in the O-ring groove 40. It is fitted in close contact with the inner diameter of the cylinder 2.

Therefore, when hydraulic pressure flows into either of the left and right power cylinders around the piston 4 in the cylinder housing 2 along the handle steering direction and the pressure rises, the left and right acting on the piston 4 Due to the pressure difference between the right power cylinder portion, the piston (4) and the rack bar (3) is to slide in the lower direction at a high pressure to assist the steering wheel steering force and to change the wheel at the same time.

In the present invention, in particular, as a means for reducing the impact noise of the piston ring 44 fitted to the piston (4) during the operation of the piston according to the steering wheel, the circumference of the inner wall both edges of the O-ring groove 40 of the piston (4) A plurality of grooves 46 are formed in the direction.

Here, the groove 46 is a groove made by cutting a part of the inner wall edge of the O-ring groove as shown in FIG. 3, and when hydraulic pressure flows into one side of the power cylinder in the cylinder housing to assist the steering wheel steering force. In addition, this inflow hydraulic pressure presses the piston ring 44 in the O-ring groove 40 in the traveling direction of the piston via the groove 46 formed in the piston 4, thereby generating a gap due to the compression of the piston ring. It becomes possible to suppress it.

Therefore, according to the present invention, when the hydraulic pressure flows into the cylinder for wheel steering, it is possible to fix the piston ring 44 on the piston 4 by using the introduced hydraulic pressure, so that the steering wheel steering As described above, it is possible to suppress the occurrence of a gap due to the compression of the piston ring 44 as described above, thereby changing the steering direction of the piston, that is, the direction in which the piston 4 interlocks with the rack bar 3. The gap at the time of change makes it possible to effectively eliminate the impact noise generated when the piston ring 44 hits the wall of the O-ring groove 40. In addition, even if a gap occurs between the piston 4 and the O-ring groove 40 when the piston 4 moves in the direction of movement as described above, the smooth movement of the piston ring 44 is induced by the hydraulic pressure introduced into the groove. Therefore, noise can be minimized.

As described above, according to the present invention, the steering gearbox piston structure allows hydraulic pressure to flow through the groove formed in the inner wall of the O-ring groove of the piston to pressurize the piston ring, thereby reducing the impact noise generated by the reciprocating motion of the piston. It can be reduced.

While the invention has been shown and described with respect to specific embodiments thereof, it will be appreciated that various changes and modifications can be made in the art without departing from the spirit or scope of the invention as set forth in the following claims. Those of ordinary skill will want to know easily.

Claims (3)

A steering wheel, a steering shaft to which the steering wheels are connected, a steering column that internally fixes the steering shaft to support the vehicle body, and is connected by the steering shaft and the link mechanism in the steering column to control the rotational movement of the steering wheel. In the steering device consisting of a gearbox for converting the linear motion of the rack bar, An o-ring groove 40 is provided in the radially central recess of the piston 4 fixedly installed on the rack bar 3 of the gearbox, and the O-ring 42 and the piston ring 44 for oil sealing in the O-ring groove 40. ) Is sequentially inserted, the outer periphery is formed on the inner wall of the O-ring groove 40 of the piston (4) so that the piston ring 44 coupled to the O-ring groove 40 by hydraulic pressure to remove noise due to the operation of the piston Steering gearbox piston structure, characterized in that the groove 46 is formed in communication with the configuration. The method of claim 1, The groove 46 is a steering gear box piston structure, characterized in that formed on both inner walls of the O-ring groove (40). The method according to claim 1 or 2, Steering gearbox piston structure, characterized in that the groove 46 is formed by forming a plurality in the circumferential direction of the piston (4).

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