KR960000781Y1 - Integral type power steering system - Google Patents

Abstract

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Description

Integrated Power Steering Device

1 is a longitudinal sectional view of an integrated power steering apparatus according to an embodiment of the present invention.

2 is an enlarged view of the main portion of FIG.

3 is a view corresponding to FIG. 2 of the second embodiment;

* Explanation of symbols for main parts of the drawings

2: gear housing 4: cylinder

6: piston 8,10: pressure chamber

12 rack 14 sector gear

15: gear room 36,38: valve

40,42: valve body 44,46: sprue

48,50: Spring 56,58: Contact

The present invention relates to an integrated power steering device.

In general, a power steering apparatus divides a cylinder into two pressure chambers by means of pistons slidingly operated in a cylinder, introduces pressure fluids controlled by a control valve in these pressure chambers, The piston is operated by the pressure difference of and the auxiliary force in the steering direction is provided.

In such a power steering apparatus, after reaching the necessary steering angle so that excessive force does not act on the steering wheel link system, a stroke limiter is provided for releasing the steering assist force and limiting the stroke of the piston. number).

The conventional power steering apparatus described above limits the stroke of the piston by providing a check valve inside the piston.

The piston is carburized and quenched to satisfy its function, and when a check valve or the like is incorporated, a processing step after carburizing and quenching is necessary.

Moreover, the stroke adjustment cannot be performed externally, and the restriction on the position of the piston circumference is also great for providing a check valve to the piston.

In addition, there are various drawbacks such as a vehicle that requires the function of limiting the stroke of the piston and a vehicle that do not need the parts that make up the power steering apparatus, and the cost-up for management is large.

The present invention has been made to eliminate the above-described drawbacks, and provides a power steering apparatus capable of limiting the stroke of the piston without making any changes to the internal parts such as the piston.

An integral type steering apparatus according to the present invention is a piston which is slide-fitted into a cylinder, a rack formed on the side of the piston, a sector gear engaged with the rack, and two formed in the cylinder by the piston. Two pressure chambers and a gear chamber in which the sector gears are accommodated and communicating with one side of the pressure chamber, wherein the control valve is switched by a steering wheel operation to supply pressure fluid to both pressure chambers. In addition to providing a valve which is opened by a predetermined rotation or more in both directions, a communication passage for connecting the pressure chamber side which does not communicate with the gear chamber and the gear chamber through the above-described valve is formed.

In the integrated power steering apparatus according to the present invention, in order to open the valve at the limit position of the rotation of the sector gear and to depressurize the pressure chamber on the high pressure side of the cylinder, no excessive force is applied to the link system after the sector axis. .

Hereinafter, the present invention will be described by the illustrated embodiment.

1 is a longitudinal sectional view showing an integral type power steering apparatus according to an embodiment of the present invention. In the cylinder portion 4 of the gear housing 2, the piston 6 is fitted with a slide operation material. The inside of the cylinder 4 is divided into two pressure chambers 8 and 10 by this piston 6.

The rack 12 is formed in the side surface (lower surface in FIG. 1) of the piston 6, and the sector gear which interlocks with the steering wheel which is not shown in this rack 12 is engaged, and the reciprocation of the piston 6 is carried out. According to the movement, it is designed to rotate forward and backward.

The gear chamber 15 in which the sector gear 14 in the gear housing 2 is accommodated communicates with one pressure chamber 10 through the passage 2a.

A bore screw groove 18 is provided in the hole 16 of the shaft portion of the piston 6, and the dignity shaft 22 is screwed through a plurality of bowls 20 in the groove 18.

A valve housing 24 is fixed to one end of the gear housing 2 described above, and a stub shaft (input shaft) 26 is provided in the valve housing 24 so as to coincide with the dignity shaft 22 and the axis line.

A cylindrical hole 22a is formed in the stub shaft 26 side of the dignity shaft 22, and the end part of the stub shaft 26 is fitted in this hole 22a, and these two shafts 22 and 26 are It is connected by the torsion bar 28 inserted in the hole of each shaft center.

And the stub shaft 26 is linked to the steering wheel not shown.

In the valve housing 24, a rotary type composed of a valve rotor 30 fitted to the outer periphery of the stub shaft 26 and integrally rotating, and a valve sleeve 32 formed on the dignity shaft 22. Control valve 34 is housed.

The control valve 34 communicates with the oil pump (not shown) via the supply passage 24a and the inlet port 24b, and with the tank via the reflux passage and the outlet port (not shown). It communicates with the pressure chamber 8 of the left direction shown through (32a), 24c, and 2b, and it communicates with the pressure chamber 10 of the right via the channel | path 32b. When the control valve 34 is converted and operated by the steering wheel, the pressure fluid discharged from the oil pump is supplied to one of the pressure chambers 8 and 10, and the other pressure chamber is connected to the tank. A pressure difference occurs between the two chambers, and the pressure difference causes the piston 6 to operate to impart an auxiliary force in the steering direction.

On the wall surface of the gear chamber 15 described above, a pair of valves (cylinder pressure control valves) 36 and 38 are located near the rotational end in the left and right directions of the sector gear 14 which rotates in accordance with the movement of the piston 6. Is installed.

These valves 36 and 38 are formed in cylindrical valve bodies 40 and 42 which are screwed into the valve holes 2c and 2d formed in the gear housing 2 and in the valve bodies 40 and 42. The springs 44 and 46 which fit the slide operation material and the springs 44 and 46 which lay the springs 44 and 46 toward the gear chamber 15 are provided.

Annular stoppers 52 and 54 are screwed into the inner openings of the valve bodies 40 and 42, and are fixed by crossing the ends of the valve bodies 40 and 42. As shown in FIG.

The spurs 44 and 46 are provided with pins 44a and 46a which penetrate the inside of the annular stopper 52 and 54 and protrude into the gear chamber 15, and the sector gear 14 rotates. It rotates up to the limit and contacts the pins 44a and 46a, and the springs 44 and 46 are pushed into the valve bodies 40 and 42 against the springs 48 and 50.

Further, the gear chamber 15 and the spring are formed through the radial passages 44b and 46b formed at the bases of the pins 44a and 46a and the axial passages 44c and 46c in the springs 44 and 46. (48) (50) The concentration room is in communication.

Through-holes 40a and 42a and annular grooves 40b and 42b are formed on the wall surfaces of the cylindrical valve bodies 40 and 42.

The annular grooves 40b and 42b of both the valve bodies 40 and 42 are connected to the pressure chamber 8 on the left side of the drawing which is not in communication with the gear chamber 15 via the communication passages 56 and 58, respectively. It communicates with the passage 2b.

When the springs 44 and 46 are inoperative, the through-holes of the valve bodies 40 and 42 are blocked by the large diameter portions of the springs 44 and 46, and when operated, the springs 44 The pins 44a and 46a of the head 46 move into the through holes 40a and 42a to open the through holes 40a and 42a, and the gear chamber 15 and the pressure chamber 8 on the left side of the drawing. An aisle 2b communicates with the communication passages 56 and 58.

The operation of the integral type power steering apparatus according to the above configuration will be described.

When the control valve 34 is changed by the operation of the steering wheel, the pressurized oil from the pump is supplied to one pressure chamber 8 or 10, and the hydraulic oil in the other pressure chamber 10 or 8 is supplied. Is refluxed to the tank, and the piston 6 is moved by the pressure difference between the two chambers 8 and 10 to rotate the sector gear 14.

In the normal power steering operating state, the sector gear 14 does not rotate to the position where it touches the pins 44a and 46a at the tip of the springs 44 and 46 of both valves 36 and 38, and Since the hydraulic pressure acting on both ends of the springs 44 and 46 is the same pressure, the force for moving the springs 44 and 46 is not generated.

On the other hand, after the tire has reached the extreme position and the driver again applies excessive pressure to the steering wheel, for example, when shifting to the left side, the gear chamber 15 and the pressure chamber 10 in communication therewith This pressure becomes high, the pressure chamber 8 on the left side becomes low pressure, the piston 6 moves to the left side, and the sector gear 14 rotates and reaches the position shown on the virtual line of FIG.

As a result, the spring 44 of the left side valve 36 is pushed down by the sector gear 14, and the pin 44a of the spring 44 is through-hole 40a of the cylindrical valve body 40. The gear chamber 15 and the pressure chamber 8 on the left side communicate with each other through the through hole 40a, the annular groove 40b, the communication passage 56, and the passage 2b. The high pressure oil in the inside flows into the pressure chamber 8 of low pressure.

Therefore, the gear chamber 15 and the right pressure chamber 10 are depressurized, so that no sector shaft torque is necessary.

On the contrary, in the case of the right shift, the gear chamber 15 and the right pressure chamber 10 become low pressure, the pressure chamber 8 on the left becomes high pressure, and the piston 6 moves to the right, and the sector gear ( 14) rotates clockwise.

As described above, when excessive input is applied and the valve 38 on the right side operates, the gear chamber 15 of the low pressure and the left pressure chamber 8 of the high pressure communicate with the through hole 42a and the annular groove 42b. 58 and the passage 2b are connected, and the pressure chamber 8 on the left side is depressurized.

The tire angle adjustment can be performed by adjusting the entire valve assembly with screws.

In the above embodiment, the valves 36 and 38 are provided in both rotational directions of the sector gear 14, but in the case where there is anxiety in strength in only one direction, for example, a valve and a communication passage are provided only on one side thereof. You may also

3 shows a second embodiment, the basic structure of which is the same as the above-described embodiment, the same parts being denoted by the same reference numerals, and the description thereof is omitted.

In this embodiment, the spring 60 having a U-shaped cross section instead of the annular stoppers 52 and 54 screwed to the valve bodies 40 and 42 as the stopper for the springs 44 and 46. (One valve 38 is not shown) is attached to the openings of the valve bodies 40 and 42.

In this embodiment, the same effects as in the above embodiment can be achieved.

As described above, according to the present invention, the link system after the sector axis can be protected by reducing the high pressure cylinder pressure chamber at the gearing extreme position of the gear and limiting the output of the power steering.

Claims (7)

A piston (6) fitted in the cylinder (4) by sliding operation, a rack (12) formed on the side surface of the piston (6), a sector gear (14) engaged with the rack (12), and the piston Two pressure chambers 8 and 10 divided by (6) and formed in the cylinder 4 and the above-mentioned sector gear 14 are accommodated, and the gear chamber 15 communicating with one side of the pressure chamber is provided. In the integrated power steering apparatus which converts the control valve by steering wheel operation and supplies pressure fluid to both pressure chambers 8 and 10, the predetermined direction of the sector gear 14 in both directions is provided. In addition to providing a valve to be opened by the above-described rotation, the communication passages 56 and 58 for connecting the pressure chamber 8 side which is not in communication with the gear chamber 15 and the gear chamber via the above-described valves are provided. Integrated power steering device characterized in that formed. 2. An integrated power steering apparatus according to claim 1, wherein said valve is provided only in one side of the rotational direction of the sector gear (14). The integral type power steering apparatus according to claim 1, wherein the valve is provided in both rotation directions of the sector gear (14). The communication passage (56) or (58) according to claim 1, wherein the communication passages (56) and (58) provide a passage for supplying fluid from the rotary valve and the gear chamber (15) to the pressure chamber (8) which is not in communication with the gear chamber (15). An integral type power steering apparatus, characterized in that for connecting. 2. The valve according to claim 1, wherein the valve includes a cylindrical valve body (40) and (42), a spring (44) and (46) fitted with a slide operation in the valve body, and the valve body (40). Springs 48 and 50 accommodated in the springs 42 and 42, and the springs 44 and 46 are pressed against the springs, and the front end of the springs 44 and 46 are protruded into the gear chamber 15. Integrated power steering system. 6. The integrated power steering apparatus according to claim 5, wherein the valve is joined in a valve hole formed in the housing, and the amount of projection of the spout tip into the gear chamber is adjustable. 7. A chamber according to claim 6, wherein the interior of the springs (48) and (50) in the valve bodies (40) and (42) is in constant communication with the gear chamber via a passage formed in the spring. Integrated power steering device.