JP4584303B2 - Power steering apparatus and manufacturing method thereof - Google Patents

Description

  The present invention relates to a power steering device that assists a driver's steering force with hydraulic pressure and a method of manufacturing the same.

  Conventionally, in the power steering device disclosed in Patent Document 1, a control valve is formed by an inner valve portion provided on the outer periphery of the input shaft and an outer valve portion provided on the inner periphery of the output shaft. The configuration is such that the left and right steering assist forces are obtained by distributing hydraulic oil through the.

When assembling, the input shaft and output shaft are inserted into the valve housing to form a control valve, a piston is attached to the output shaft, and the gear housing for housing the sector gear and the valve housing are supported by jigs (chucking). ). Thereafter, the piston and the output shaft are inserted into the gear housing with both the central axes aligned.
JP 2005-22636 A

  However, in the above prior art, the valve housing and the gear housing are chucked with different jigs, and the piston and the output shaft are inserted into the gear housing while the shaft centers of both housings are aligned. It was complicated.

  On the other hand, if the positioning accuracy is lowered and the process is simplified, the misalignment between the piston and the gear housing becomes large and the piston slides and the backlash between the piston and the gear housing is caused through the piston. It is transferred to the clearance between the output shaft and the input shaft, and the operation of the control valve formed by the input / output shaft is deteriorated. Further, since the coupling surface between the gear housing and the valve housing is also a sealing surface for the hydraulic oil, a decrease in positioning accuracy is not preferable from the viewpoint of ensuring sealing performance.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a power steering device that simplifies the process while ensuring positioning accuracy.

To achieve the above object, the present invention, the valve housing side coupling surface provided on the gear housing side of the valve housing, provided in the valve housing side of the gear housing, the valve housing side coupling surface that abuts gear A housing side coupling surface, a valve accommodating portion provided in the valve housing, a piston accommodated in the gear housing, and defining the inside of the gear housing into a first pressure chamber and a second pressure chamber; and the input shaft; An inner valve portion rotatably accommodated in the valve accommodating portion , and provided integrally with the output shaft, and provided on the outer peripheral side of the inner valve portion and rotatably in the valve accommodating portion. and a outer valve portion is constituted by, constructed from the inner valve portion and the outer valve portion, the inner valve And a valve portion that selectively switches a hydraulic oil supply path from an external hydraulic source to the first pressure chamber or the second pressure chamber by relative rotation between the valve housing portion and the outer valve portion. An oil groove provided between the parts, a ball bearing provided between the valve housing part and the outer valve part and formed from an inner race, an outer race, and a ball, and the valve housing part, the gear housing. A conversion mechanism that is formed so as to face the side and that is configured to include a bearing contact surface that contacts an axial end surface of the ball bearing , and a conversion unit that converts rotation of the output shaft into axial movement of the piston. And a transmission mechanism for transmitting the axial movement of the piston to the steered wheels, wherein the ball bearing includes the inner valve portion and the outer valve. A first pressure chamber communication passage that is provided on the gear housing side and is formed on the outer valve portion, and communicates with the inner peripheral side of the outer valve portion and the first pressure chamber. An annular fixed plug that is inserted from the gear housing side and fixes the outer race to the valve housing side, and an end portion on the inner peripheral side of the outer valve portion of the first pressure chamber communication passage overlap with the ball bearing in the axial direction. The end of the first pressure chamber communication path on the first pressure chamber side is open to the inner peripheral portion of the fixed plug .

  Therefore, it is possible to provide a power steering device that simplifies the process while ensuring positioning accuracy.

  Hereinafter, the best mode for realizing the power steering apparatus of the present invention will be described based on the embodiments shown in the drawings.

[Overall configuration of power steering system]
Example 1 will be described. FIG. 1 is an axial sectional view of the power steering device, and FIG. 2 is a radial front view of the output shaft 60 alone. 3 is a front view of the valve housing 10 in the y-axis positive direction, and FIG. 4 is a sectional view of the valve housing 10 in the axial direction.

  Note that the axial direction of the input / output shafts 40 and 60 is defined as the y-axis, and the input shaft 40 side is positive. Further, when viewed from the piston 70 side, the sector shaft 30 (transmission mechanism) side is the x-axis positive direction.

  The housing member 1 of the power steering apparatus includes a valve housing 10 that houses a control valve 600 that switches an assist direction, and a gear housing 20 that houses a piston 70 that generates assist force by hydraulic pressure. Moreover, it has the sector shaft 30 which meshes with the piston 70 and rotates by the reciprocating motion of the piston 70 to steer a steered wheel (not shown).

  Both the valve housing 10 and the gear housing 20 are substantially cup-shaped members and are connected to each other in the axial direction opening. The valve housing 10 has valve housing side coupling surfaces 13 and 14, and the gear housing 20 has gear housing side coupling surfaces 26 and 27. Each has axial coupling surfaces 13 and 26 parallel to the y-axis and radial coupling surfaces 14 and 27 perpendicular to the y-axis.

  The sliding part 25 of the gear housing 20 and the piston 70 is cylindrical. An input shaft 40 and an output shaft 60 connected to a steering wheel SW (not shown) are inserted into the valve housing portion 11 on the inner peripheral side of the valve housing 10.

  In accordance with the rotation of the input / output shafts 40, 60, the piston 70 in the gear housing 20 is slid in the y-axis direction by hydraulic pressure. The valve housing 10 is provided with a suction port 410 for supplying and discharging hydraulic oil and a discharge port 420, and is connected to an oil pump O / P (external hydraulic power source).

  Further, the gear housing 20 and the sector shaft 30 are provided at right angles to each other in the axial direction, and the tooth portion 71 provided on the piston 70 in the gear housing 20 and the tooth portion 31 provided on the sector shaft 30 mesh with each other, and the piston slides. The sector shaft 30 is rotated by the movement to perform steering assist.

  A piston 70 is accommodated in the gear housing 20 so as to be movable in the axial direction. The piston 70 causes the gear housing 20 to have a first pressure chamber 21 on the y-axis positive direction side and a second pressure chamber 22 on the y-axis negative direction side. It is separated while maintaining liquid tightness.

  The input shaft 40 is connected to the output shaft 60 by a torsion bar 50. The output shaft 60 is inserted into the piston 70 in the axial direction, and is fitted to the piston 70 by a ball screw (ball nut) 80. Further, a piston tooth portion 71 carved in the circumferential direction is provided on the outer periphery of the piston 70, and the piston 70 meshes with the sector shaft 30 in the piston tooth portion 71. The output shaft 60 is provided with a torsion bar press-fitting hole 63, and the y-axis negative direction side end portion of the torsion bar 50 is press-fitted and connected.

  The ball screw 80 includes a screw 81, a nut 82, and a ball 83. The screw 81 is formed by providing a ball screw groove 84 on the outer peripheral side of the output shaft 60 and on the negative y-axis side of the control valve 600 (outer valve portion 620), and the nut 82 is formed on the inner peripheral side of the piston 70. The The ball 83 is provided between the screw 81 and the nut 82 and converts the rotation of the outer valve portion 620 into the movement of the piston 70 in the y-axis direction.

  Since the output shaft 60 is provided with a ball screw groove 84 on the outer peripheral side and a torsion bar press-fitting hole 63 on the inner peripheral side, there is a concern about insufficient strength. Therefore, the y-axis direction positions of the ball screw groove 84 and the torsion bar press-fitting hole 63 are shifted from each other and separated from each other to ensure the strength of the output shaft 60.

  The piston 70 is supported by the output shaft 60 by inserting the screw 81 into the nut 82 from the y-axis positive direction side (valve housing 10 side). Here, the y-axis negative direction side end portion 62 of the output shaft 60 does not contact the bottom portion 24 of the gear housing 20, and the output shaft 60 is not supported by the gear housing 20.

  Further, the piston 70 and the gear housing 20 are merely slid, and the gear housing 20 does not positively support the piston 70. For this reason, the piston 70 is cantilevered by the valve housing 10 and the output shaft 60.

  As a result, the pressure receiving area on the second pressure chamber 22 side in the piston 70 becomes the same as the radial cross-sectional area of the sliding portion 25 on the inner periphery of the gear housing 20, and the pressure receiving area on the second pressure chamber 22 side increases. Is effectively moved in the y-axis direction.

  The gear housing 20 is provided so that its axis is orthogonal to the sector shaft 30, and a sector shaft storage portion 23 for storing a part of the sector shaft 30 is provided in a part of the gear housing 20 in the radial direction. Hydraulic oil is introduced into the sector shaft storage portion 23 and communicates with the first pressure chamber 21 to lubricate the sector shaft 30 and the piston tooth portion 71 in mesh.

  The first pressure chamber 21 in the gear housing 20 communicates with the control valve 600 through the first pressure chamber communication passage 15 provided in the valve housing 10, and the second pressure chamber 22 is provided across the gear housing 20 and the valve housing 10. The second pressure chamber communication passage 16 is communicated with the control valve 600.

  The control valve 600 includes an inner valve portion 610 formed on the input shaft 40 and an outer valve portion 620 formed on the output shaft 60. The inner valve portion 610 is formed by recessing the outer periphery of the input shaft 40 in the inner peripheral direction, and the outer valve portion 620 is formed by recessing the inner periphery of the output shaft 60 toward the outer peripheral side.

  The inner valve portion 610 has an inner valve groove 611 that is recessed in the inner diameter direction, and the outer valve portion 620 has an outer valve groove 621 that is recessed in the outer diameter direction. A plurality of valve grooves 611 and 621 are provided in the circumferential direction, and a seal ring 630 is provided between the grooves 611 and 621.

  The outer valve portion 620 is provided with oil grooves 310 and 320, and the control valve 600 is connected to the suction port 410 and the discharge port 420 via the oil grooves 310 and 320. Accordingly, the control valve 600 functions as a control valve mechanism that introduces or discharges oil from the suction port 410 and the discharge port 420 to the first and second pressure chambers 21 and 22 according to the rotation of the input shaft 40.

  When the input shaft 40 rotates to the left and right relative to the output shaft 60, the oil pump O / P communicates with the first pressure chamber 21 or the second pressure chamber 22.

  The oil grooves 310 and 320 are provided on the outer peripheral side of the outer valve portion 620. When it is provided in the valve housing part 11 of the valve housing 10, since it is necessary to make a groove on the inner periphery of the valve housing 10, workability is poor, but it is easily processed by providing it on the outer peripheral side of the outer valve part 620.

  A bearing contact surface 17 is provided on the outer peripheral side of the outer valve portion 620 (the outer peripheral side of the output shaft 60), and a ball bearing 100 (bearing) is provided on the bearing contact surface 17. The ball bearing 100 is a four-point thrust bearing that supports the output shaft 60 in a rotatable manner and takes a reaction force when a force in the y-axis direction acts on the output shaft 60.

  The bearing ball 130 is sandwiched between an inner race portion 110 that is integral with the output shaft 60 and provided on the outer periphery, and an outer race portion 120 that is separate from the output shaft 60. By integrating the inner race part 110 with the output shaft 60, the positioning of the control valve 600 is improved as compared with the case where the inner race part 110 is not integrated.

  A bearing ball groove 121 is provided on the outer periphery of the inner race portion 110 to hold the bearing ball 130. In addition, the inner race portion 110 (the output shaft 60) and the first outer ball groove 621 and the outer periphery of the outer valve portion 620 communicate with the bearing ball groove 121 on the y-axis negative direction side (the screw 81 side of the ball screw 80). A pressure chamber communication passage 15 (oil passage) is provided.

  When the outer valve portion 620 and the output shaft 60 are not integral, a member constituting the outer valve portion 620 is separately provided. In this case, an oil passage (the first pressure chamber communication) that connects the outer valve groove 621 and the outer periphery of the output shaft 60 is provided. It is difficult or complicated to form the passage 15). In the present application, since the outer valve portion 620 and the output shaft 60 are integrated, it is possible to easily form the first pressure chamber communication passage 15 only by drilling from the outer periphery of the output shaft 60.

  A fixed plug 140 is provided on the y-axis negative direction side of the outer race portion 120. The fixed plug 140 is a member that is inserted into the valve accommodating portion 11 of the valve housing 10 from the first pressure chamber 21 side and locks the y-axis negative direction side of the outer race portion 120. The outer race portion 120 is fixed by the fixed plug 140. Is fixed to the valve housing 10. The first pressure chamber communication passage 15 opens to the inner peripheral portion of the fixed plug 140.

  Since the input shaft 40 and the output shaft 60 are inserted into the valve housing 10 from the y-axis negative direction side, the fixed plug 140 is also inserted from the y-axis negative direction side. Further, the bearing contact surface 17 is also provided to face the y-axis negative direction side so that the ball bearing 100 is inserted and fixed from the y-axis negative direction side.

  In addition, a seal member 150 that seals the valve housing 10 and the outside on the y-axis positive direction side of the control valve 600 is also inserted from the y-axis negative direction side prior to the input shaft 40. The seal member 150 is locked to the flange portion 12 provided at the y-axis positive direction end portion of the valve housing 10 and is surrounded on the outer side (y-axis positive direction side). There is no need to provide a dust seal on the side.

  Each member (input / output shafts 40, 60, ball bearing 100, seal member 150, fixed plug 140) accommodated in the valve housing 10 can be inserted into the valve housing 10 from the y-axis negative direction side. , Improve workability.

  A needle bearing 640 is provided between the inner valve portion 610 and the outer valve portion 620 and on the positive side of the valve grooves 611 and 621 in the y-axis direction. On the other hand, no bearing is provided on the negative side of the y-axis of each of the valve grooves 611 and 621, and surface contact is made. For the sliding between the inner valve portion 610 and the outer valve portion 620, it is sufficient to provide the needle bearing 640 only on the y-axis positive direction side. .

  Therefore, the needle bearing 640 may be provided only on the y-axis negative direction side, or both the positive and negative direction sides of the y-axis may be omitted without providing the needle bearing 640.

  The needle bearing 640 is provided in a needle bearing holding groove 612 provided on the outer peripheral side of the inner valve portion 610 (input shaft 40). Since it is complicated to groove the outer valve portion 620 (output shaft 60) on the inner peripheral side, the outer valve portion 610 is provided on the outer periphery to facilitate the processing.

[Details near the control valve]
The ball bearing 100 is provided on the y-axis negative direction side of the outer valve portion 620. Also, when this passes through the center O _B of the bearing balls 130 of the ball bearing 100, defines a virtual line K inclined by 45 ° to the y-axis positive direction to the x-axis in the inner circumference side, the output shaft 60 y-axis positive The direction side end 61 is located on the y axis positive direction side with respect to the straight line K. Therefore, the flesh is present on the y axis positive direction side of the straight line K.

  When a force F in the y-axis direction is applied to the output shaft 60, the force F is decomposed into a force in the 45 ° direction with respect to the x and y axes by the bearing balls 130 of the ball bearing 100, and the inner race portion 110 of the ball bearing 100. Act on. Among the resolved forces, the force on the y-axis positive direction side acts along an imaginary line K, and the force on the y-axis negative direction side acts along a straight line orthogonal to the imaginary line K.

  In the embodiment of the present application, the imaginary line K and the y-axis positive direction side end portion 61 do not intersect each other, and therefore the weakest portion of the outer valve portion 620 is the inner peripheral side of the outer valve portion 620 and the y-axis positive direction side end portion. 61 and the outer valve groove 621 and the inner circumferential surface of the ball bearing 100 and the inner race part 110 side.

  Therefore, the distance between the bearing ball 130 and the y-axis positive direction side end 61 on the imaginary line K is increased, the distance of the weakest portion is increased, the strength is improved, and the possibility of breakage is reduced.

[Assembly process]
(First step: Chucking)
The valve housing 10 is chucked at the chucking position. The chucking position A is the y-axis positive direction side (input shaft 40 and steering wheel side) of the valve housing 10.

(Second process: Valve housing inner peripheral surface machining)
From the y-axis negative direction side (gear housing 20 side) of the valve housing 10, the valve housing portion 11 that is the inner peripheral surface is cut and polished.

(3rd step: Inter-housing contact surface processing)
The coupling surfaces 13 and 14 with the gear housing 20 are cut and polished from the y-axis negative direction side (gear housing 20 side) of the valve housing 10.

(4th step: valve assembly insertion / gear housing assembly)
After the seal member 150 is inserted into the valve housing 10, the valve assembly of the control valve 600 formed by the input / output shafts 40, 60, etc. is inserted from the y-axis negative direction side. The output shaft 60 and the piston 70 may be assembled to the gear housing 20 in advance, or the output shaft 60 and the piston 70 may be assembled to the valve housing 10 first, and then the gear housing 20 may be assembled.

  In this way, by adopting a configuration in which all the assembly can be performed from the y-axis negative direction side, the assembly process is performed with the valve housing 10 chucked from the y-axis positive direction side, thereby simplifying the process.

[Effect of Example 1]
(1) a valve housing side coupling surface 26 provided on the gear housing 20 side of the valve housing 10;
Gear housing side coupling surfaces 13 and 14 that are provided on the gear housing 20 side of the valve housing 10 and abut against the valve housing side coupling surface 26;
A valve housing portion 11 provided in the valve housing 10;
An inner valve portion 610 that is integral with the input shaft 40 and is rotatably accommodated in the valve accommodating portion 11;
An outer valve portion 620 provided integrally with the output shaft 60 and on the outer peripheral side of the inner valve portion 610 and rotatably provided in the valve housing portion 11;
The inner valve portion 610 and the outer valve portion 620 are configured to operate from the external hydraulic source O / P (oil pump) to the first pressure chamber 21 or the second pressure chamber 22 by relative rotation between the inner valve portion 610 and the outer valve portion 620. A control valve 600 (valve part) for selectively switching the oil supply oil path;
Oil grooves 310 and 320 provided between the valve housing portion 11 and the outer valve portion 620;
A bearing member 100 provided between the valve housing portion 11 and the outer valve portion 620;
A bearing abutment surface 17 which is the valve accommodating portion 11 and is formed to face the y-axis negative direction side (gear housing 20 side), and abuts the axial end surface of the bearing member 100;
A ball screw 80 (conversion unit) that converts the rotation of the output shaft 60 into the axial movement of the piston 70 and a conversion mechanism are provided.

  By adopting a configuration in which all the assembly can be performed from the y-axis negative direction side, the assembly process can be performed in a state where the valve housing 10 is chucked from the y-axis positive direction side. Therefore, it is possible to provide a power steering device that simplifies the process while ensuring positioning accuracy.

  (2) The bearing member 100 is the ball bearing 100 formed from the inner race portion 110, the outer race portion 120, and the bearing ball 130.

  (3) The ball bearing 100 is provided on the gear housing 20 side with respect to the inner valve portion 610 and the outer valve portion 620.

  Thereby, the site | part (bearing contact surface 17) which provides the ball bearing 100 can be easily processed from the y-axis negative direction side which is an opening part of the valve housing 10. FIG.

  (4) (19) It further includes a fixed plug 140 that is inserted into the valve housing 10 from the y-axis negative direction side (gear housing 20 side) and fixes the outer race portion 120 of the ball bearing 100 to the valve housing 10 side. .

  Thereby, the ball bearing 100 can also be assembled in one direction from the y-axis negative direction side.

  (5) The inner race part 110 of the ball bearing 100 is formed integrally with the outer valve part 620. By forming them integrally, positioning is less and accuracy is better than when other members are used separately. In addition, the number of parts can be reduced.

  (6) The ball bearing 100 is a four-point thrust bearing. Thereby, not only a y-axis direction but a radial load can be received.

  (7) It further includes an in-valve bearing 640 provided between the inner valve portion 610 and the outer valve portion 620.

  (8) The in-valve bearing 640 is a needle bearing. Since the needle bearing is small, space can be saved.

  (9) (21) The needle bearing 640 is provided in the needle bearing holding groove 612 provided so as to open to the outer peripheral side of the inner valve portion 610.

  By providing the needle bearing holding groove 612 on the outer periphery of the inner valve portion 610, processing can be performed more easily than when it is provided on the inner periphery of the outer valve portion 620.

(10) The inner valve portion 610 has a plurality of inner valve grooves 611 provided on the outer peripheral side,
The needle bearing 640 is provided on the y-axis positive direction side (one axial direction side) of the inner valve groove 611,
On the y-axis negative direction side (the other side in the axial direction) of the inner valve groove 611, the sliding between the inner valve portion 610 and the outer valve portion 620 is performed only by surface contact between the inner valve portion 610 and the outer valve portion 620.

  For the sliding between the inner valve portion 610 and the outer valve portion 620, it is sufficient to provide the needle bearing 640 only on the y-axis positive direction side. be able to.

(11) (20) The valve housing 10 further includes a seal member 150 inserted from the y-axis negative direction side (gear housing 20 side),
The seal member 150 is provided on the y-axis positive side (on the opposite side in the axial direction) with respect to the gear housing 20 and further away from the gear housing 20 than the oil grooves 310 and 320.

  Thereby, the seal member 150 can also be assembled in one direction from the y-axis negative direction side.

  (12) The flange portion 12 provided in the valve housing 10 and surrounding the outside of the seal member 150 is further included. Due to the presence of the flange portion 12, it is not necessary to provide a dust seal on the positive side of the valve housing 10 in the y-axis direction.

(13) The output shaft 60 is supported by the valve housing 10,
The piston 70 is cantilevered by the output shaft 60 from the y-axis positive direction side (valve housing 10 side).

  As a result, the y-axis negative direction side end 62 of the output shaft 60 does not contact the bottom 24 of the gear housing 20, and the pressure receiving area of the piston 70 on the second pressure chamber 22 side is slid on the inner periphery of the gear housing 20. It becomes the same as the radial cross-sectional area of the moving part 25, the pressure receiving area on the second pressure chamber 22 side is increased, and the piston 70 is effectively moved in the y-axis direction.

(14) The conversion mechanism includes a screw 81 in which a ball screw groove 84 is integrally formed on the outer peripheral side of the output shaft 60, a nut 82 provided between the screw 81 and the piston 70, and the screw 81 and the nut 82. A ball screw 80 composed of a plurality of balls 83 provided between
The output shaft 60 has a torsion bar press-fitting hole 63 into which the torsion bar 50 is press-fitted,
The output shaft 60 and the inner valve portion 610 are connected by a torsion bar 50 that is press-fitted into the torsion bar press-fitting hole 63.
The torsion bar press-fitting hole 63 and the ball screw groove 84 are provided at positions separated from each other in the y-axis direction on the output shaft 60.

  Since the output shaft 60 is provided with a ball screw groove 84 on the outer peripheral side and a torsion bar press-fitting hole 63 on the inner peripheral side, there is a concern about insufficient strength. The strength of the output shaft 60 can be ensured by shifting the directional positions and separating them from each other.

  (15) The oil grooves 310 and 320 are provided on the outer peripheral side of the outer valve portion 620. When it is provided in the valve housing portion 11 of the valve housing 10, it is necessary to make a groove on the inner periphery of the valve housing 10, so workability is poor, but it is easily processed by providing it on the outer peripheral side of the outer valve portion 620. Can do.

  (16) An inner race portion 110 that is integrally formed on the outer peripheral side of the outer valve portion 620 and provided on the screw 81 side with respect to the oil grooves 310 and 320, and a valve housing portion 11 that is formed on the outer peripheral side of the inner race portion 110. The ball bearing 100 includes an outer race portion 120 provided and a bearing ball 130 provided between the inner race portion 110 and the outer race portion 120.

  Since the ball bearing 100 is provided on the y-axis negative direction side of the outer valve portion 620 and the y-axis positive direction end 61 of the output shaft 60 is located on the y-axis positive direction side with respect to the straight line K, There will be meat on the positive side. Accordingly, the distance between the bearing ball 130 and the y-axis positive direction side end 61 on the imaginary line K is increased, the distance of the weakest portion is increased, the strength is improved, and the possibility of breakage can be reduced.

(17) It further has a first pressure chamber communication passage 15 that communicates the inner peripheral side and the outer peripheral side of the outer valve portion 620,
The first pressure chamber communication passage 15 is the inner race portion 110 of the ball bearing 100 and is formed on the screw 81 side of the bearing ball groove 121 that holds the bearing ball 130.

  The outer valve portion 620 and the output shaft 60 are not integrated, and a member constituting the outer valve portion 620 is separately provided. In this case, it is difficult to form an oil passage that connects the outer valve groove 621 and the outer periphery of the output shaft 60. Or it is complicated. In the present application, since the outer valve portion 620 and the output shaft 60 are integrated, the first pressure chamber communication path 15 can be easily formed only by drilling from the outer periphery of the output shaft 60.

(18) a first step of chucking the axial steering wheel SW side of the valve housing 10;
A second step of machining the inner peripheral surface of the valve housing portion 11 from the gear housing 20 side of the valve housing 10;
And a third step of machining the coupling surface 14 with the gear housing 20 from the gear housing 20 side of the valve housing 10.

  By adopting a configuration in which all the assembly can be performed from the y-axis negative direction side, the assembly process can be performed with the valve housing 10 chucked from the y-axis positive direction side, and the process can be simplified.

[Other embodiments]
As described above, the best mode for carrying out the present invention has been described based on the first embodiment. However, the specific configuration of the present invention is not limited to each embodiment and does not depart from the gist of the present invention. Such design changes are included in the present invention.

  In the first embodiment, the ball bearing 100 is provided on the y-axis negative direction side of the control valve 600, but may be provided on the y-axis positive direction side as shown in FIG.

It is an axial sectional view of a power steering device. It is a radial front view of the output shaft 60 alone. 3 is a front view of the valve housing 10 in the positive y-axis direction. FIG. 2 is an axial sectional view of the valve housing 10. FIG. This is another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing member 10 Valve housing 11 Valve accommodating part 12 Flange part 13, 14 Valve housing side coupling surface 15 1st pressure chamber communication path (oil passage)
16 Second pressure chamber communication path 17 Bearing contact surface 20 Gear housings 21 and 22 First and second pressure chambers 26 and 27 Gear housing side coupling surface 30 Sector shaft 40 Input shaft 50 Torsion bar 60 Output shaft 61 Y-axis positive direction Side end 63 Torsion bar press-fit hole 70 Piston 80 Ball screw 81 Screw 82 Nut 83 Ball 84 Ball screw groove 100 Ball bearing (bearing member)
110 Inner race portion 120 Outer race portion 121 Bearing ball groove 130 Bearing ball 140 Fixed plug 150 Seal member 310, 320 Oil groove 600 Control valve 610 Inner valve portion 611 Inner valve groove 612 Needle bearing holding groove 620 Outer valve portion 621 Outer valve groove 640 Needle bearing (valve Inner bearing)
O / P oil pump (hydraulic power source)
SW Steering wheel

Claims (12)

An input shaft connected to the steering wheel;
An output shaft connected to the input shaft;
A housing member comprising a valve housing and a gear housing combined with the valve housing;
A valve housing side coupling surface provided on the gear housing side of the valve housing;
A gear housing side coupling surface that is provided on the valve housing side of the gear housing and abuts on the valve housing side coupling surface;
A valve housing provided in the valve housing;
A piston housed in the gear housing and defining the inside of the gear housing into a first pressure chamber and a second pressure chamber;
An inner valve portion that is integral with the input shaft and is rotatably accommodated in the valve accommodating portion;
An outer valve portion which is provided integrally with the output shaft and which is provided on the outer peripheral side of the inner valve portion and is rotatably provided in the valve housing portion;
The inner valve portion and the outer valve portion are configured, and a hydraulic oil supply passage from the external hydraulic source to the first pressure chamber or the second pressure chamber is selected by relative rotation between the inner valve portion and the outer valve portion. A valve part to be switched automatically,
An oil groove provided between the valve housing portion and the outer valve portion;
A ball bearing provided between the valve housing portion and the outer valve portion and formed from an inner race, an outer race, and a ball ;
A bearing contact surface that is formed so as to be opposed to the gear housing side in the valve housing portion, and is in contact with an axial end surface of the ball bearing ;
A conversion unit configured to convert rotation of the output shaft into axial movement of the piston;
It possesses a transmission mechanism for transmitting the axial movement of the piston to the steered wheels,
The ball bearing is provided on the gear housing side with respect to the inner valve portion and the outer valve portion,
A first pressure chamber communication path formed in the outer valve portion and communicating the inner valve side of the outer valve portion and the first pressure chamber;
An annular fixed plug inserted from the gear housing side into the valve housing and fixing the outer race to the valve housing side;
An end of the first pressure chamber communication path on the inner peripheral side of the outer valve portion is disposed at a position overlapping the ball bearing in the axial direction,
An end portion of the first pressure chamber communication path on the first pressure chamber side opens to an inner peripheral portion of the fixed plug . The power steering apparatus according to claim 1, wherein
The power steering device according to claim 1, wherein an inner race of the ball bearing is formed integrally with the outer valve portion . In the power steering device according to claim 1 or 2,
The power steering device, wherein the ball bearing is a four-point thrust bearing . The power steering device according to any one of claims 1 to 3 ,
The power steering device further comprising an in-valve bearing provided between the inner valve portion and the outer valve portion . The power steering apparatus according to claim 4 , wherein
The power steering device according to claim 1, wherein the in-valve bearing is a needle bearing . In the power steering device according to claim 5 ,
The power steering device according to claim 1, wherein the needle bearing is provided in a needle bearing holding groove provided so as to open to an outer peripheral side of the inner valve portion . The power steering apparatus according to any one of claims 4 to 6 ,
The inner valve portion has a plurality of valve grooves provided on the outer peripheral side,
The in-valve bearing is provided on one axial side of the valve groove,
The power steering device according to claim 1, wherein the inner valve portion and the outer valve portion are slid only by surface contact between the inner valve portion and the outer valve portion on the other axial side of the valve groove . The power steering apparatus according to claim 1 ,
A seal member inserted from the gear housing side with respect to the valve housing;
The power steering device according to claim 1, wherein the seal member is provided on the opposite side in the axial direction with respect to the gear housing and further away from the gear housing than the oil groove . The power steering device according to claim 8,
A power steering apparatus , further comprising a flange portion provided in the valve housing and surrounding an outer side of the seal member . The power steering apparatus according to claim 1 , wherein
The output shaft is supported by the valve housing,
The power steering apparatus , wherein the piston is cantilevered from the valve housing side by the output shaft . The power steering apparatus according to claim 1, wherein
The conversion mechanism is provided between a screw having a ball screw groove integrally formed on the outer peripheral side of the output shaft, a nut provided between the screw and the piston, and between the screw and the nut. A ball screw composed of a plurality of balls,
The output shaft has a torsion bar press-fitting hole into which the torsion bar is press-fitted,
The output shaft and the inner valve portion are connected by the torsion bar press-fitted into the torsion bar press-fitting hole,
The power steering device according to claim 1, wherein the torsion bar press-fitting hole and the ball screw groove are provided at positions spaced apart from each other in the axial direction on the output shaft . The power steering apparatus according to claim 1 , wherein
The power steering device according to claim 1, wherein the oil groove is provided on an outer peripheral side of the outer valve portion .

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