KR940004611Y1 - Power-driven steering - Google Patents

Abstract

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Description

Power steering

1 is a cross-sectional view of a power steering device showing an embodiment of the present invention.

2 is an enlarged view of the main part thereof.

FIG. 3 is a cross sectional view along line III-III in FIG. 2 showing the structure of the leaf springs and holders.

FIG. 4 is a cross sectional view along line IV-IV in FIG. 2 showing the structure of leaf springs and holders.

5 is a configuration diagram showing a state before the leaf spring is attached to the holder.

* Explanation of symbols for main parts of the drawings

22: output shaft (worm shaft) 22a: hole

26: input shaft 28: torsion bar spring

30: valve rotor 32: valve sleeve

34: control valve (rotary valve) 40: leaf spring

40a: arc portion 40b: contact portion

42: flat surface 44: bolt

46 holder 46a: penetrating portion

46b: accommodating part 48: holder side contact part

The present invention relates to a power steering apparatus, and more particularly, to a power steering apparatus in which an input shaft and an output shaft are connected to each other via a torsion bar spring.

Conventionally, for example, as disclosed in Japanese Unexamined Patent Publication No. 43-6022, an input shaft rotated by a steering wheel and an output shaft disposed on the same axis as the input shaft are connected by a torsion bar spring. In addition, a rotary valve is constituted by a pair of valve members provided to rotate integrally with each of the two shafts, and the rotary valves are switched according to the relative rotational displacement of the two shafts to the power cylinder. BACKGROUND OF THE INVENTION Power steering devices which are designed to control the pressure delivery of pressure fluids are generally known.

By the way, in the conventional power steering apparatus described above, only the reaction mechanism and the torsion rod spring are used. Therefore, the micro steering angle at high speed, the responsiveness of the micro steering angle at high speed, or the steering force of the micro steering angle at high speed, etc. There is a problem that the number of corrections increases because of poor controllability in the steering angle region.

The present invention has been made in view of the present situation, and it is possible to reduce the number of modifications to the handle by improving the responsiveness in the small steering angle region, the steering wheel restoration, the steering sensation at the start of steering, and the straightness. It is an object of the present invention to provide a power steering apparatus that can operate.

The present invention is an apparatus which achieves the above object, characterized in that one or more flat surfaces are formed on the outer circumferential surface of the input shaft and the plate springs supported by the output shaft are pressed against the flat surfaces.

In the power steering apparatus according to the present invention, the leaf spring supported by the output shaft is pressed against the flat surface formed on the outer circumferential surface of the input shaft, and the tightening force is applied by the elasticity of the leaf spring. Therefore, the response in the micro steering angle region, the steering wheel restoration, the steering sensation at the start of steering, and the straightness can be improved, and the predetermined number of steering wheels can be reduced.

EXAMPLE

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an example of an integrated power steering apparatus according to the present invention, and the piston 6 is inserted in the cylinder portion 4 of the gear housing 2 so as to be slidable, and the piston 6 The inside of the cylinder 4 is divided into two pressure chambers 8 and 10. A rack 12 is formed on the side surface (lower in FIG. 1) of the piston 6, and the rack 12 has a sector gear 14 that cooperates with a steering wheel (not shown in the drawing). ) Is engaged and is to be rotated forward and backward by the reciprocating operation of the piston (6).

A bore screw groove 18 is formed in a spiral in the hole 16 of the shaft portion of the piston 6, and an output shaft (worm shaft) 22 via a plurality of bowls 20 in the bore screw groove 18. ) Is fastened by screws. The valve housing 24 is fixed to one end of the above-mentioned gear housing 2, and the input shaft (stub shaft) 26 is arrange | positioned in this valve housing 24 so that the axis line with the said output shaft 22 may be matched. . The cylindrical hole 22a is formed in the input shaft 26 side of the output shaft 22, The edge part 26a of the input shaft 26 is inserted in this hole 22a, and these two shafts 22, ( 26 is connected by a torsion bar spring 28 inserted into a hole on each axis line. In the insertion portion of the input shaft 26 of the output shaft 22, a fail safe is configured to allow a predetermined amount of relative rotation of both shafts 22 and 26, and to restrict further rotation.

In addition, the input shaft 26 is configured to interlock with a steering wheel (display in the drawing is omitted).

In the valve housing 24, a rotary control valve including a valve rotor 30 connected to the input shaft 26 and integrally rotating with the input shaft 26 and a valve sleeve 32 formed on the output shaft 22. 34 is housed.

The control valve 34 communicates with an oil pump (not shown in the drawing) via a supply path and a tank (not shown in the drawing) via a reflux path. When the control valve 34 is switched, the pressure fluid discharged from the oil pump is supplied to the pressure chamber of one of the pressure chambers 8 and 10, and the pressure chamber of the other side is in communication with the tank. The pressure difference is generated between the pressure chambers, and the pressure difference is actuated to provide an auxiliary force in the steering direction.

As shown in FIG. 1, the end of the valve slide 32 constitutes an inner race of the bearing 36, and the output shaft 22 is provided with the valve housing described above via the bearing 36. The base end portion of the input shaft 26 is supported by the valve housing 24 via the bearing 38 in a rotational state. And between these bearings 36 and 38, as shown in FIG. 1 and FIG. 2, the leaf | plate spring 40 which gives fastening force to the input shaft 26 is assembled.

That is, the portions located between the bearings 36 and 38 of the input shaft 26, as shown in FIGS. 3 and 4, are cut flat on both sides facing the radial direction. Flat surfaces 42 are formed, respectively, and the outer surface of each of these flat surfaces 42 is press-fitted to each of the leaf springs 40 having a hat-shaped cross section, and both of the leaf springs 40 are shown in FIG. As shown in FIG. 4, it is accommodated in the holder 46 fixed to the cross section of the said valve slide 32 via the bolt 44. As shown in FIG.

As shown in FIGS. 3 and 4, the holder 46 has a penetrating portion 46a through which the input shaft 26 penetrates, and is located on both sides of the penetrating portion 46a. The leaf spring accommodating part 46b etc. which have the width of L) are formed, and it is formed by sintering or casting, and the flat surface mentioned above is at the upper and lower ends of the through part 46a side of each accommodating part 46b. The holder side contact parts 48 which coincide with 42 are formed, respectively.

On the other hand, as shown in FIG. 5, the leaf spring 40 is formed by the circular arc portion 40a and the contact portions 40b on both sides thereof, and the cross section is formed in the shape of a fed hat. In the state which is not accommodated in the accommodating part 46b of the inside, it is set so that it may become length L 'larger than the length L of the accommodating part 46b. The leaf spring 40 is elastically deformed and accommodated in the housing portion 46b, whereby the above contact portions 40b are pressed against the knitted surface 42 to provide a fastening force to the input shaft 26.

Next, the operation of the present embodiment will be described.

As shown in FIGS. 3 and 4, each of the leaf springs 40 accommodated in the respective housing portions 46b of the holder 46 has its contact portion 40b formed on the flat surface of the input shaft 26. 42) is pressed against the outer shaft. Therefore, the clamping force is applied to the input shaft 26 at the neutral position of the control valve 34 by the elasticity of the both leaf springs 40 mentioned above.

Therefore, the response in the small steering angle region, the restoration of the handle and the steering force sense at the start of steering can be improved, as well as the straightness can be improved, and the number of corrections of the handle can be reduced.

In addition, in the above-mentioned embodiment, the case where the flat surface 42 is formed in two places of the outer peripheral surface of the input shaft 26, and the fastening force is given to the input shaft 26 using two or more even leaf springs was demonstrated. When one or more leaf springs 40 are press-contacted to one flat surface 42, a desired effect can be obtained.

Moreover, after assembling the control valve 34 which consists of the output shaft 22, the input shaft 26, the torsion rod spring 8, the valve rotor 30, the pin 29, etc., the holder 46 and the board | plate are assembled. A presetting mechanism composed of a spring 40 is attached to the control valve 34 using a bolt, in which a gap is formed between the bolt 44 and the bolt hole, and the By fixing to the position of equilibrium by the paired leaf spring 40, the elastic force of the presetting mechanism can also maintain equilibrium.

As described so far, the present invention is designed to form a flat surface by processing one or more places on the outer circumferential surface of the input shaft and press-fit the plate spring supported on the output shaft to obtain a clamping force. The response in the small steering angle region can be improved, the steering wheel restoration can be improved, the steering force can be improved, and the straightness can be improved, and the number of corrections of the steering wheel can be reduced.

Claims (1)

The input shaft 26 rotates by the steering wheel, the output shaft 22 disposed on the same axis as the input shaft 26, and the input / output shafts 26 and 22, respectively, so that integral rotation is possible. And a torsion bar spring (28) disposed at the shaft member of the valve member and the input / output shafts (26) and (22) constituting the battery valve, and connecting the two shafts. In the power steering apparatus in which the end of the other shaft is inserted into the hole 22a formed in the one end, at least one flat surface 42 is formed in the outer peripheral surface of the input shaft 26, and this flat surface 42 The power steering device, characterized in that for pressing the leaf spring (40) supported by the output shaft (22).