JPH0332507B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a cylinder device used for power assistance of a power steering device, and particularly to a cylinder device used in a rack and pinion type power steering device.

<Prior Art> Generally, in such cylinder devices, the cylinder device integrated with the servo valve device is installed in a horizontal state on a support frame disposed in the lower part of the engine room of an automobile, and then the piping is connected to the pump unit. However, in this state, air remains inside the cylinder device, so it is necessary to vent the air by some method.

In order to make this air removal easier, it is possible to form the supply and discharge holes of the cylinder device at the top of the cylinder body, and to supply and discharge pressure oil from above the cylinder device. In a cylinder device in which a shaped pipe is used as the cylinder body and a cylindrical boss is welded to the cylinder body as a pipe attachment part, the central axis of the boss is It is necessary to fix the cylinder at a position that matches the diameter line of the cylinder body, and with the conventional boss shape where the connection hole for attaching the plumbing pipe is formed on the axis parallel to the central axis of the boss, the pipe attachment part of the boss is Since it faces upward, the vicinity of the cylinder device installation side of the piping that communicates between the cylinder body and the servo valve device extends considerably above the cylinder body, and when the engine is located above the cylinder body, has the problem of interfering with the oil pan etc. installed at the bottom of the engine.

<Purpose of the Invention> The present invention has been made in view of these conventional problems, and it can be installed even when there is no large space above the cylinder body, and the air remaining in the cylinder body can be easily removed. It is an object of the present invention to provide a cylinder device for a power steering device with a simple structure that can be removed.

<Structure of the Invention> In order to achieve the above object, the present invention fixes a cylindrical boss diagonally above the outer periphery of a cylinder body with its central axis aligned with the diameter line of the cylinder body, and the boss has the following features: A communication hole whose one end opens above the cylinder body and a connection hole for connecting a piping pipe are formed on an inclined axis that is inclined in a tangential direction touching the upper part of the cylinder body with respect to the central axis of the boss. be.

<Examples> Examples of the present invention will be described below based on the drawings. In FIG. 1, 10 is a rack-and-pinion type power steering device, and this power steering device 10 is supported by a pair of support bands 12, 12 so that the axis of the cylinder device 11 is horizontal. It is mounted on a mounting frame 13 of an automobile. A pair of tie rods 15, 15 connected to both ends of a rack shaft passing through the cylinder device 11 in the axial direction via a universal joint are connected to a knuckle arm (not shown).

A servo valve device 16 whose input shaft is connected to a handle via a connecting rod and a universal joint (not shown) is integrally attached to the right end of the cylinder device 11, and the servo valve device 16 and the cylinder device 11 A pair of plumbing pipes 17, 17 communicates between the two, so that hydraulic oil can flow therethrough. Further, the servo valve device 16 is connected to the power steering device 1
After the power steering device 10 is attached to the frame 13, it is connected to a pump unit (not shown) disposed above the power steering device 10 through a piping. Note that 18 is an oil pan attached to the bottom of the engine.

Next, the structure of the piping pipe attachment part in the cylinder device 11, which is a feature of the present invention, will be explained.
is constituted by a cylindrical pipe, and bosses 21, 21 for pipe attachment are welded to the outer periphery of this cylinder body 20.

In other words, the bosses 21, 21 are cylinders having an arcuate mounting surface 22 formed at one end of the cylinder centered on the central axis L1, and a flat notch 23 formed at the other end, as shown in FIGS. 2 to 4. The central axis L1 of the bosses 21, 21 having such a shape is diagonally above the axis of the cylinder body 20.
its arcuate mounting surface 22 to match the diameter line of
It is welded to the outer periphery of the cylinder body 20 by.

Connection holes 24, communication holes 25, and supply/discharge holes 26 are bored in the bosses 21, 21 and the cylinder body 20. The connection hole 24, the communication hole 25, and the supply/discharge hole 26 are located at the upper part of the cylinder body 20 with respect to the central axis L1 of the bosses 21, 21 so as to open upwardly of the cylinder body 20 when welded to the cylinder body 20. It is formed to be inclined in the tangential direction.

Due to this inclination, the amount of upward protrusion of the tightening nut 30 screwed into the connection hole 24 and the pipe 31 fixed by this tightening nut 30 is small, and interference with the oil pan 18 is prevented.

Note that 28 indicates a sheet member that engages with a flared portion formed at the tip of the pipe, and the flared portion of the pipe 31 is held between this sheet member 28 and the sleeve 30.

The bosses 21, 21 are welded by projection welding. In this case, as shown in FIG.
, and place the boss 21 on the cylinder body 20 placed on the support block 36 so that its center axis L1 is
is positioned so that it passes through the center of the cylinder body 20 and faces in the vertical direction. Then, the upper electrode 35 is lowered to apply a predetermined pressing force, and in this state, a predetermined voltage is applied between the upper electrode 35 and the support block 36 serving as the lower electrode.
The arcuate mounting surface 22 is melted by Joule heat, and the boss 21 is welded to the outer periphery of the cylinder body 20. At this time, since a pressing force can be applied to the boss 21 in the direction of its central axis L1, that is, in the diametrical direction of the cylinder body 20, the boss 21 may become misaligned during welding work, or the cylinder body 20 may
There is no risk of rotation, and welding work can be performed reliably.

In addition, the connection hole 24, the communication hole 25, and the supply/discharge hole 2
6, each hole 24, 2 is machined as shown in FIG.
The cylinder body 20 and the bosses 21, 21 are supported by the support block 38 so that the axis L2 opening upward of the cylinder bodies 20 of Nos. 5 and 26 is oriented vertically.
Position the drill tool 38 from above.
Alternatively, it can be easily processed by lowering the tap tool.

In the cylinder device having the above configuration, the boss 21,
Since the tightening nut 30 and the pipe 31 are oriented substantially horizontally, the piping does not interfere with the oil pan 18 located above the cylinder device 11, and the supply/discharge hole 26 is located near the top. Since it can be perforated, air remaining inside the cylinder body can also be easily removed.

That is, in order to vent air, the power steering device 1
After installing the 0 in the car and connecting the piping to the pump unit, air is removed using a vacuum pump, etc., and then hydraulic oil is supplied and discharged. However, in this state, air remains in the cylinder. ing. To remove this air, operate the pump to supply pressurized oil, and in this state rotate the steering wheel left and right several times to the end of its stroke. As a result, the piston in the cylinder device also moves repeatedly from the neutral position to the left stroke end and right stroke end, thereby causing the cylinder device 11
The air inside is exhausted from the supply/exhaust port. Since the piston stroke end is the position where the universal joint attached to the end of the rack shaft engages with the locking surface of the cylinder device, there is a considerable gap between the piston in the cylinder device and the inner surface of the end of the cylinder. Although air remains here, this air is also discharged through the supply/discharge hole 26 after the above operation is performed several times. Note that the air discharged from this supply/discharge hole 26 flows through the pipes 31, 31 and the servo valve device 16.
through the pump unit to the hydraulic tank of the pump unit, from where it is released to the atmosphere.

<Effects of the Invention> As described above, in the present invention, a cylindrical boss is fixed diagonally above the outer periphery of a cylinder body with its central axis aligned with the diameter line of the cylinder body, and the boss has a , a communication hole whose one end opens above the cylinder body and a connection hole for connecting a piping pipe are formed on an inclined axis that is inclined in a tangential direction touching the upper part of the cylinder body with respect to the central axis of the boss. Therefore, even if there is an oil pan, etc. near the top of the cylinder device, the supply/discharge hole can be formed near the top of the cylinder device, which has the advantage that air remaining in the cylinder device can be easily removed. There is.

Furthermore, since the connection hole and the communication hole are formed on the same axis, each hole can be machined at the same time, which has the advantage that the process is easy and the shape of the boss can be simplified.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an external view showing the installed state of a rack-and-pinion type power steering device, and FIG. 2 is an enlarged sectional view taken along the line - in FIG. Fig. 3 is a cross-sectional view taken along the - line in Fig. 2, Fig. 4 is a cross-sectional view taken along the - line in Fig. 3, Fig. 5 is a view showing the state when the boss is welded, and Fig. 6 is a view showing the processing state of the boss. FIG. 10...Power steering device, 11...Cylinder device, 20...Cylinder body, 21...Boss, 24
... Connection hole, 25 ... Communication hole, L1 ... Center axis line, L2 ... Inclined axis line.

Claims (1)

[Claims] 1. In a cylinder device for a power steering system in which a cylindrical cylinder body into which a piston is fitted is mounted horizontally on a vehicle, a cylindrical boss is installed diagonally above the outer periphery of the cylinder body so that its central axis is aligned with the cylinder body. The cylinder body is fixed so as to match the diameter line of the cylinder body, and the boss has a communication hole whose one end opens above the cylinder body and a connection hole for connecting a piping pipe to the cylinder body with respect to the central axis of the boss. A cylinder device for a power steering device, characterized in that the cylinder device is formed on an inclined axis that is inclined in a tangential direction and touches an upper part of a main body.