JPH0966850A - Rotary servo valve body unit for hydraulic type power steering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly absorb axial depth error in the cylindrical stepped part and axial dimensional error in the rolling bearing outer ring by interposing a continuous trapezoidal turn-up shape spring washer composed of a flat surface part on one side with a slant surface part inclined to the other side, and a flat surface part on the other side with a slant surface part inclined to one side toward circumferential direction. SOLUTION: A continuous trapezoidal turn-up shape spring washer 44, which is composed of a flat surface part 45 on one side with a slant surface part 47 inclined to the other side, and a flat surface part 46 on the other side with a slant surface part 48 inclined to one side, as advancing clockwisely along the circumferential direction, is interposed in the stepped part 38 of a valve housing 10 and the stepped part 39 of a gear housing 11. Error in the dimension between both ends of step parts 38, 39, when the valve housing 10 and the gear housing 11 are connected together, and the dimension in the axial width of an outer ring 41 of a rolling bearing 40 can be absorbed by the elastic deformation of the continuous trapezoidal turn-up shape spring washer 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary servo valve body unit of a hydraulic power steering device for reducing a steering force of an automobile, which hermetically seals an input shaft and a sleeve fitted to the outer periphery of the input shaft. Both end faces of the valve housing, the output shaft arranged on the same axis through the input shaft and the torsion bar, and the gear housing for sealing the rack meshing with the pinion integral with the output shaft are butt-joined to each other, and the butt joint is made. Located inside the joint,
The present invention relates to a rotary servo valve body unit for fixing an outer ring of a rolling bearing pivotally supporting the output shaft so as to be immovable in the axial direction.

[0002]

2. Description of the Related Art Japanese Patent Application No. 5-75932 filed by the present applicant
No. 1 is constructed as shown in FIGS.

That is, the rotary servo valve body unit 01 is constructed as shown in FIG. 8, and in the rotary servo valve body unit 01, the valve housing 02 and the gear housing 03 are arranged so that they are located on the same axis. And a stub shaft 04 is rotatably fitted to the valve housing 02, and a stub shaft sleeve 05 is rotatably fitted concentrically between the valve housing 02 and the stub shaft 04. The inner end of the pinion 07, which is the output shaft, is rotatably fitted to the outer circumference of the inner end of the stub shaft 04 via the bearing 06, and the outer end of the pinion 07 is attached to the gear housing 03 via the rolling bearing 08. It is rotatably fitted.

Further, a hollow center hole 09 is formed in the stub shaft 04, a torsion bar 010 is fitted in the center hole 09, and the outer end of the torsion bar 010 is integrally coupled to the stub shaft 04 and The inner end of the torsion bar 010 is integrally connected to the pinion 07, and the stub shaft 04 and the pinion 07 are relatively rotatably connected by the torsional deformation of the torsion bar 010.

Further, the valve housing 02 has an oil supply port.
An oil drain port 012 and an oil drain port 012 are formed, and a left cylinder port 013 and a right cylinder port 014 that communicate with the left and right cylinder chambers of a power cylinder (not shown) are formed.

[0006] Furthermore, a step portion 015 circumferentially oriented inwardly of the contact portion between the valve housing 02 and the gear housing 03,
016 are formed respectively, and the outer ring 018 of the rolling bearing 017 is fitted to the step portions 015 and 016, and the inner ring 019 of the rolling bearing 017 is fitted to the outer periphery of the pinion 07, and the stopper ring 020 fitted to the pinion 07. The inner ring 019 of the rolling bearing 017 is fixed so as not to move in the axial direction.

Further, the stepped portion 015 of the valve housing 02 and the outer ring 018 of the rolling bearing 017 are formed in a circular truncated cone shape in which the outer peripheral edge portion 023 of the frustoconical spring washer 021 is curved toward the end surface 027 of the outer ring 018 on the valve housing side. When the spring washer 021 is installed and the valve housing 02 and the gear housing 03 are combined, the rolling bearing 01
The axial backlash of 7 is removed, and the axial tolerance of the pinion 07 and rolling bearing 017 and the cumulative tolerance of the assembly tolerance of the valve housing 02 to the gear housing 03 are absorbed by the elastic deformation of the truncated cone spring washer 021. It has become so.

[0008]

In the frustoconical spring washer 021 shown in FIGS. 8 to 9, a frustoconical portion is provided at the inner peripheral edge portion 026 where the inner peripheral surface 024 of the valve housing 02 and the end surface 025 of the step portion 015 intersect. The outer curved surface 022 of the outer spring washer 021 locally abuts, a large stress is locally generated at the abutting portion of the outer curved surface 022, and permanent strain is likely to occur at that portion. As shown in the figure, after the load is increased from 0 to A ₁ and the displacement becomes B ₁ , the load is reduced to 0.
When returned to 0, the displacement does not return to 0, the displacement becomes C ₂ , a relatively large hysteresis X ₂ remains, and the deformable amount of the frustoconical spring washer 021 after one use is B ₁ -X. ₂ = Y ₂ , and when the deformable amount Y ₂ becomes a value that is less than or equal to the cumulative tolerance Δ of the axial tolerance of the pinion 07 and the rolling bearing 017 and the assembly tolerance of the valve housing 02 to the gear housing 03, the truncated cone spring washer is used.
Reuse of 021 becomes impossible and the frustoconical spring washer 021 is replaced less frequently, resulting in higher maintenance and maintenance costs.

In the rotary servo valve body unit 01 shown in FIGS. 8 to 9, when the direction of the curved surface of the frustoconical spring washer 021 is reversed, the frustoconical spring washer 021 is elastically deformed. Since it was impossible to absorb the cumulative tolerance, it was necessary to be careful when assembling the truncated cone spring washer 021.

Further, in the above-mentioned application, as another embodiment, the frustoconical spring washer 021 is replaced with the corrugated curved spring washer 028 shown in FIGS. 11 to 12.

The wavy curved spring washer 028 is
It is formed into a wavy curved shape as it goes in the circumferential direction,
Both top surface portions 029 of the wavy curved spring washer 028 abut on the end surface 025 of the stepped portion 015 of the valve housing 02 and the end surface 027 of the outer ring 018 of the rolling bearing 017 at the initial contact line 030 directed radially. The axial clamping force of the stub shaft 04,
The wavy curving spring washer 028 is easily deformed as shown in FIG. 13, that is, its elastic coefficient is small (the inclination angle of the displacement-load curve is small), so it gives a large deformation to obtain the required holding reaction force. As necessary, the end face of step 015
The amount of sliding of the initial contact line 030 with respect to the valve housing side end surface 027 of the outer ring 018 and the outer ring 018 is remarkably increased, and as a result, the wavy curved spring washer 028 has a large hysteresis X ₂ like the truncated cone spring washer 021.

[0012]

SUMMARY OF THE INVENTION The present invention relates to an improvement of a rotary servo valve body unit that overcomes the above problems, and relates to an input shaft and an output shaft arranged on the same axis through a torsion bar. A valve housing, which is relatively twistably connected and has a sleeve fitted relatively rotatably to the outer periphery of the input shaft, and seals the input shaft and the sleeve, forms the output shaft and the output shaft. A rotary servo valve body unit for a hydraulic power steering device, comprising: a gear housing that seals a rack that meshes with an integral pinion; and a valve housing end portion and a gear housing end portion that are butt-joined to each other. A rolling bearing is provided inside the housing end and the gear housing end to pivotally support the output shaft. One end surface of the outer ring is brought into contact with the inner end surface of the cylindrical stepped portion of the gear housing, and the other end surface of the outer ring and the inner end surface of the cylindrical stepped portion of the valve housing form one flat surface portion in the circumferential direction. It is characterized in that a spring washer having a continuous trapezoidal folded shape including an inclined surface portion inclined to the other side, another plane portion and an inclined surface portion inclined to one side is interposed.

Since the present invention is constructed as described above,
Even if there is an error in the axial depth of each cylindrical step of the valve housing and gear housing and the axial dimension of the outer ring of the rolling bearing, the elastic deformation of the continuous trapezoidal folded spring washer causes the shaft of the outer ring of the rolling bearing. Since the direction play is removed, the axial depth error of the cylindrical stepped portion and the axial dimension error of the rolling bearing outer ring are reliably absorbed.

Further, since both outer surfaces of the continuous washer-shaped folded-back-shaped spring washer for locking the outer ring of the plain bearing are flat, the frictional force of the flat outer surface due to the deformation of the spring washer is reduced and slipping becomes easier. , The absorbed energy when the spring washer is deformed is reduced, and the hysteresis (the amount of residual deformation that cannot be restored to the original shape when the spring washer is attached to the rotary servo valve body unit and then removed) ) Becomes small, and for the purpose of maintenance and maintenance, the rotary servo valve body unit can be disassembled into a valve housing and a gear housing to increase the number of times the spring washer is reused. As a result, the frequency of replacement of the spring washers can be reduced, and maintenance and maintenance costs can be reduced.

Further, since the continuous washer-folded spring washer is formed symmetrically on both sides of the center plane of the thickness, the spring washer has no front and back sides,
The spring washer can be mounted on the rotary servo valve body unit efficiently and easily without paying attention to the front and back of the spring washer.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention shown in FIGS. 1 to 6 will be described below. As shown in FIG. 1, a hydraulic power steering device 1 is arranged in front of a vehicle body, and an outer end of a stub shaft 12 of a rotary servo valve body unit 2 which is laid on the hydraulic power steering device 1 will be described below. A power cylinder 6 connected to a steering column shaft 4 integrated with a steering wheel 3 via a steering joint 5 and integrally connected to a rotary servo valve body unit 2.
Inside, a piston (not shown) is slidably fitted,
A tip of a tie rod 7 connected to the piston is pivotally attached to a knuckle arm attached to a front wheel 8, and a hydraulic pump 9 for supplying pressure oil to a valve housing 10 in the rotary servo valve body unit 2 is connected to the knuckle arm. The stub shaft 12 is provided near the power cylinder 6, and when the steering wheel 3 is rotated in either direction, the stub shaft 12 is rotationally driven correspondingly, and the operation of the rotary servo valve body unit 2 causes the power cylinder to rotate. The piston in 6 slides left and right, and the front wheel 8 is steered left and right.

In the rotary servo valve body unit 2 attached to the hydraulic power steering system 1 shown in FIG. 1, the valve housing 10 and the gear housing 11 are on the same axis as shown in FIG. Stub shaft 12, which is an input shaft, is rotatably fitted to the valve housing 10, and the valve housing 10 and the stub shaft
A stub shaft sleeve 13 is concentrically and rotatably fitted between the stub shaft sleeve 12 and the stub shaft 12, and a bearing 14 is provided on the outer circumference of the inner end of the stub shaft 12.
The inner end of the pinion 15, which is the output shaft, is rotatably fitted to the gear housing 11 via the rolling bearing 16, while the outer end of the pinion 15 is rotatably fitted to the gear housing 11 via the rolling bearing 16.

A hollow center hole 17 is formed in the stub shaft 12, and a torsion bar 18 is fitted in the center hole 17, and the outer end of the torsion bar 18 is integrally connected to the stub shaft 12 and The inner end of the torsion bar 18 is integrally connected to the pinion 15, so that the stub shaft 12 and the pinion 15 are relatively rotatably connected by the torsional deformation of the torsion bar 18.

Further, as shown in FIG. 2, a rack 19 oriented in the vehicle width direction is slidably fitted in the gear housing 11, and the rack 19 has a piston (not shown) of the power cylinder 6 as described above. It is connected to the front wheel 8 via the tie rod 7 and the tie rod 7. When the pinion 15 rotates, the rack 19 slides left and right, and the front wheel 8 turns left and right.

The valve housing 10 has a hydraulic pump 9
Is formed with an oil supply port 20 and an oil discharge port 21, which are respectively connected to the discharge port and the suction port of the power cylinder 6, and a left cylinder port 22 and a right cylinder port 23 which are connected to left and right cylinder chambers (not shown) of the power cylinder 6. Has been done.

Further, a circumferential oil supply groove 24 communicating with the oil supply port 20 is formed on the outer peripheral surface of the stub shaft 12, and a circumferential left cylinder communicating with the left cylinder port 22 and the right cylinder port 23, respectively. A groove 25 and a circumferential right cylinder groove 26 are formed on both axial sides of the circumferential oil supply groove 24.

Further, as shown in FIG. 3, the stub shaft sleeve 13 has four oil supply passages 27 which are oriented toward the central axis thereof and whose outer ends are open to the circumferential oil supply groove 24.
Are formed at equal intervals over the circumferential direction, and the left cylinder passage 28 and the right cylinder passage 29 are directed to the center line of the stub shaft sleeve 13 on both circumferential sides of the oil supply passage 27.
Are formed, and the outer ends of the left cylinder passage 28 and the right cylinder passage 29 are opened to the circumferential left cylinder groove 25 and the circumferential right cylinder groove 26, respectively.

Moreover, the center of the left cylinder passage 28 and the center of the right cylinder passage 29 are aligned with the center of the groove on the inner peripheral surface of the stub shaft sleeve 13.
Axial grooves 30 and 31 parallel to the axial direction of 4 are alternately arranged, 4 in total
The inner ends of the left cylinder passage 28 and the right cylinder passage 29 are open to the axial grooves 30 and 31, respectively.

On the outer peripheral surface of the stub shaft 12, axial grooves 32, 33 having a width equal to the width of the portion of the stub shaft sleeve 13 sandwiched by the axial grooves 30, 31 are alternately arranged at equal intervals in the circumferential direction. Is formed in the stub shaft 12 to form an oil drain passage 34 that connects the center hole 17 of the stub shaft 12 to the axial groove 33. The center hole 17 is connected to the oil drain port 21 via another oil drain passage 35. .

Further, as shown in FIG. 2, a locking pin 36 is provided on the pinion 15 side of the stub shaft sleeve 13 so as to project toward the center, and an axial engagement groove 37 is formed on the stub shaft sleeve 13 side of the pinion 15. The engaging pin 37 is engaged with the engaging groove 37, and the rotation of the pinion 15 is transmitted to the stub shaft sleeve 13.

Furthermore, a step portion 38 oriented in the circumferential direction inwardly of the abutting portion between the valve housing 10 and the gear housing 11,
39 are respectively formed, and the rolling bearings are formed on the step portions 38 and 39.
The outer ring 41 of the rolling bearing 40 is fitted, the inner ring 42 of the rolling bearing 40 is fitted on the outer periphery of the pinion 15, and the inner ring of the rolling bearing 40 is fitted by the stopper ring 43 fitted on the pinion 15.
42 is fixed so as not to move in the axial direction.

Moreover, in the step portion 38 of the valve housing 10 and the step portion 39 of the gear housing 11, one flat surface portion 45 and an inclined surface portion 47 inclined to the other as proceeding clockwise in the circumferential direction in FIG. A continuous trapezoidal folded-back spring washer 44 composed of a flat surface portion 46 on the other side and an inclined surface portion 48 inclined to the one side is interposed, and both step portions 38 when the valve housing 10 and the gear housing 11 are connected to each other. The errors in the dimension between both end faces of the roller bearing 39, 39 and the axial width of the outer ring 41 of the rolling bearing 40 can be absorbed by the elastic deformation of the continuous trapezoidal folded spring washer 44.

Further, oil seals 49 and 50 are provided on both sides of the stub shaft sleeve 13 in the valve housing 10 in the axial direction, so that the pressure oil in the valve housing 10 does not leak to the outside. To be formed.

Since the embodiment shown in FIGS. 1 to 6 is configured as described above, when the steering wheel 3 rotates to the left (counterclockwise when viewed from the driver's seat),
The stub shaft 12 overcomes the torsional reaction force of the torsion bar 18 and rotates in the same direction as the steering wheel 3 with respect to the stub shaft sleeve 13, and the axial groove 32 of the stub shaft 12 becomes the axial groove 30 of the stub shaft sleeve 13. The pressure oil flowing from the oil supply port 20 into the axial groove 32 via the oil supply groove 24 in the circumferential direction and the oil supply passage 27 flows from the axial groove 30 into the left cylinder passage 28, the circumferential left cylinder groove 25, and the left cylinder groove 25. It flows into the left cylinder chamber of the power cylinder 6 via the one cylinder port 22, the piston (not shown) moves to the right, and the steered wheels 8 face to the left. The oil discharge state in the right cylinder chamber is omitted.

The pinion 15 and the stub shaft sleeve 13 rotate in the same counterclockwise direction as the counterclockwise rotation direction of the stub shaft 12 in response to the rightward movement of the piston and the rack 19 (not shown), and the rotation angle of the stub shaft 12 increases. When the stub shaft sleeve 13 rotates at a rotation angle equal to, the communication between the axial groove 32 and the axial groove 30 is cut off,
The supply of hydraulic oil to the power cylinder 6 is stopped.

The inner ring 42 of the rolling bearing 40 is a pinion 15
It is fixed so as not to move in the axial direction by the step portion of and the stopper ring 43, and the axial play of the outer ring 41 of the rolling bearing 40 is on the end surface 51 of the step portion 38 of the valve housing 10 and the end surface 52 of the outer ring 41. Since it is removed by elastic deformation of the inserted continuous trapezoidal folded spring washer 44, the step portion 38,
39 axial depth tolerance and rolling bearing 40 outer ring 41
The cumulative axial tolerance, which is the tolerance of the axial dimension of the, is absorbed.

Further, on both sides of the continuous trapezoidal folded spring washer 44, a flat surface 45 having a smooth surface and a flat surface portion are provided.
Since 46 is formed, the continuous trapezoidal folded-back spring washers 44 are formed on the end surface 51 of the step portion 38 and the end surface 52 of the outer ring 41.
When the flat surface portion 45 and the flat surface portion 46 contact each other, the frictional force between the contact surfaces is small, and the elastic coefficient of the continuous trapezoidal folded spring washer 44 is large. Similar to the trapezoidal spring washer 021, a small deformation is sufficient to obtain the required holding reaction force, and the flat surface portion 45 and the flat surface portion of the continuous trapezoidal folded-back spring washer 44 with respect to the end surface 51 of the step portion 38 and the end surface 52 of the outer ring 41. The sliding force of 46 is small, so that the continuous trapezoidal folded spring washer 44 has a small hysteresis X ₁ as shown in FIG.

Therefore, as shown in FIG. 7, the deformable amount of the continuous trapezoidal folded spring washer 44 after one use of the continuous trapezoidal folded spring washer is B ₁ -X ₁ = Y _1. Since it is relatively large, the number of times the continuous trapezoidal folded spring washer 44 is reused is increased, the frequency of replacement of the continuous trapezoidal folded spring washer 44 is reduced, and maintenance and maintenance costs are reduced.

Furthermore, since there is no difference between the front and back of the continuous trapezoidal folded-back spring washer 44, the front and back of the continuous trapezoidal folded-back spring washer 44 is not distracted,
The continuous servo-type spring washer 44 can be easily attached to the rotary servo valve body unit 2.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating an entire hydraulic power steering apparatus including a rotary servo valve body unit according to the present invention.

FIG. 2 is a vertical sectional side view showing an embodiment of the rotary servo valve body unit of the present invention shown in FIG.

3 is a cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a plan view of a continuous trapezoidal folded spring washer.

5 is a view taken along the line VV of FIG.

FIG. 6 is an enlarged vertical side view of an essential part of FIG.

FIG. 7 is a characteristic diagram illustrating a state of elastic deformation and hysteresis of the continuous trapezoidal folded spring washer in the embodiment of the present invention.

FIG. 8 is a vertical sectional side view of a conventional rotary servo valve body unit.

9 is an enlarged vertical side view of an essential part of FIG.

FIG. 10 is a characteristic diagram illustrating states of elastic deformation and hysteresis of the end faces illustrated in FIGS. 8 to 9.

FIG. 11 is a perspective view of a wavy curving spring washer in another conventional rotary servo valve body unit.

FIG. 12 is a cross-sectional view in which the wavy curving spring washer is cut in the circumferential direction in a state where the one shown in FIG. 11 is applied to a rotary servo valve body unit.

FIG. 13 is a characteristic diagram illustrating a state of elastic deformation and hysteresis of the left cylinder passage illustrated in FIG.

[Explanation of symbols]

1 ... Hydraulic power steering device, 2 ... Rotary servo valve body unit, 3 ... Steering wheel,
4 ... Steering column shaft, 5 ... Steering joint, 6 ... Power cylinder, 7 ... Tie rod, 8 ...
Front wheel, 9 ... Hydraulic pump, 10 ... Valve housing, 11 ... Gear housing, 12 ... Stub shaft, 13 ...
Stub shaft sleeve, 14 ... Bearing, 15 ... Pinion, 16
… Rolling bearing, 17… Center hole, 18… Torsion bar, 19
… Rack, 20… Oil supply port, 21… Oil drain port, 22… Left cylinder port, 23… Right cylinder port, 24… Circumferential oil supply groove, 25… Circumferential left cylinder groove, 26… Circumferential direction right Cylinder groove, 27 ... Oil supply passage, 28 ... Left cylinder passage, 29 ...
Right cylinder passage, 30, 31, 32, 33 ... Axial groove, 34, 35
... Oil drainage passage, 36 ... Locking pin, 37 ... Engagement groove, 38, 39 ... Step portion, 40 ... Rolling bearing, 41 ... Outer ring, 42 ... Inner ring, 43 ... Stopper ring, 44 ... Continuous trapezoidal folded spring washer , 45, 46… Plane part, 47, 48… Inclined surface part, 49, 50… Oil seal, 51, 52… End surface.

Claims (1)

[Claims] 1. An input shaft and an output shaft arranged on the same axis are connected via a torsion bar so that they can be twisted relative to each other, and a sleeve is fitted on the outer periphery of the input shaft so as to be relatively rotatable. Forming a valve housing that seals the input shaft and the sleeve, and forming a gear housing that seals the output shaft and a rack that meshes with the output shaft and a pinion that is integral with the output shaft, the valve housing end and the gear housing end In a rotary servo valve body unit of a hydraulic power steering device formed by butt-joining a shaft portion with a roller portion, a rolling bearing that is positioned inside the valve housing end portion and the gear housing end portion and pivotally supports the output shaft. And the one end surface of the outer ring of the rolling bearing is brought into contact with the inner end surface of the cylindrical stepped portion of the gear housing, and the other end surface of the outer ring and the valve housing With the inner end surface of the cylindrical stepped portion of the stepped spring washer having a continuous trapezoidal folded-back shape including one flat surface portion, an inclined surface portion inclined to the other side, and the other flat surface portion and an inclined surface portion inclined to one side in the circumferential direction. The rotary servo valve body unit of the hydraulic power steering device, which is characterized by being equipped.