WO2024058015A1 - Dispositif de direction - Google Patents

Dispositif de direction Download PDF

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Publication number
WO2024058015A1
WO2024058015A1 PCT/JP2023/032443 JP2023032443W WO2024058015A1 WO 2024058015 A1 WO2024058015 A1 WO 2024058015A1 JP 2023032443 W JP2023032443 W JP 2023032443W WO 2024058015 A1 WO2024058015 A1 WO 2024058015A1
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WO
WIPO (PCT)
Prior art keywords
rack shaft
buffer member
rack
rack bar
steering device
Prior art date
Application number
PCT/JP2023/032443
Other languages
English (en)
Japanese (ja)
Inventor
昌也 竹野
剛 千葉
要 永利
良晃 城戸
祐也 佐藤
Original Assignee
日立Astemo株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日立Astemo株式会社 filed Critical 日立Astemo株式会社
Publication of WO2024058015A1 publication Critical patent/WO2024058015A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D3/00—Steering gears
    • B62D3/02—Steering gears mechanical
    • B62D3/12—Steering gears mechanical of rack-and-pinion type

Definitions

  • the present invention relates to a steering device.
  • a rubber buffer member is attached to the outer peripheral side of the axial end of the rack bar. This buffer member is compressed and deformed by being sandwiched between the ball joint connected to the axial end of the rack bar and the housing (rack housing), thereby buffering the collision between the housing (rack housing) and the ball joint. do.
  • the present invention was devised in view of such technical problems, and provides a steering device that can ensure stable shock absorbing characteristics of a shock absorbing member.
  • the recessed portion for attaching the buffer member to the rack shaft has a first inclined surface and a second inclined surface that are asymmetrical in the axial direction of the rack shaft, and the first inclined surface However, the slope is gentler than the second slope.
  • FIG. 1 is a schematic diagram of a steering device according to the present invention.
  • FIG. 2 is a cross-sectional view taken along line AA in FIG. 1.
  • 2 is a sectional view taken along line BB in FIG. 1.
  • FIG. FIG. 2 is an enlarged view of the vicinity of the axial end of the rack bar shown in FIG. 1;
  • FIG. 4 is an enlarged view of the main part of FIG. 3, showing a state of the buffer member before deformation.
  • FIG. 4 is an enlarged view of the main part of FIG. 3, showing the state of the buffer member after deformation in the lock end state.
  • FIG. 1 is a schematic diagram of the steering system according to the present embodiment, showing a partial cross-sectional view of the vicinity of the end of the rack bar 3 along the axial direction of the rack bar 3. As shown in FIG.
  • the steering device includes a steering mechanism SM that transmits the driver's steering force, and a steering assist mechanism AM that assists the driver's steering operation. Further, this steering device is suspended on the body of an automobile (not shown) via a pair of brackets BKT attached to the rack housing 1 that accommodates the steering mechanism SM.
  • the steering mechanism SM is connected to a steering wheel (not shown) at one end, a steering shaft 2 which is a pinion shaft having pinion teeth (not shown) formed at the other end, and a steered wheel (not shown).
  • the rack bar 3 is a rack shaft formed with rack teeth (not shown) that mesh with pinion teeth of the rack bar 3. Note that the steering shaft 2 and the rack bar 3 are linked via a conversion mechanism not shown. Further, the conversion mechanism includes the pinion teeth (not shown) formed on the other end side of the steering shaft 2 (output shaft 22 described later), and the rack teeth (not shown) formed on the rack bar 3. It is also a so-called rack and pinion mechanism.
  • the housing 1 is made of a metal material, for example, an aluminum alloy material, and mainly includes a steering shaft accommodating part 11, a retainer accommodating part 12, a rack bar accommodating part 13, and a transmission mechanism accommodating part 14 integrally.
  • the steering shaft accommodating portion 11 extends along the direction of the rotation axis Z of the steering shaft 2, and is formed into a generally cylindrical shape capable of accommodating the steering shaft 2 therein.
  • the retainer accommodating part 12 is formed in a generally cylindrical shape on the back side of the rack bar 3 so as to intersect with the steering shaft accommodating part 11 and perpendicular to the rack bar accommodating part 13.
  • a rack retainer (not shown) that supports the sides is housed inside.
  • the rack bar accommodating portion 12 extends along the direction of the central axis X of the rack bar 3, intersecting with the steering shaft accommodating portion 11, and is formed into a generally cylindrical shape capable of accommodating the rack bar 3 therein.
  • the steering shaft 2 is constructed by connecting an input shaft 21 that rotates integrally with a steering wheel (not shown) and an output shaft 22 that is linked to a rack bar 3 by a torsion bar (not shown).
  • the input shaft 21 has one end (the upper end in FIG. 1) in the direction of the rotational axis Z of the steering shaft 2 connected to a steering wheel (not shown), and the other end connected to a torsion bar (not shown).
  • the output shaft 22 has one end (upper end in FIG. 1) connected to a torsion bar (not shown) in the direction of the rotation axis Z of the steering shaft 2, and the other end linked to the rack bar 3.
  • pinion teeth are formed on the outer periphery of the other end of the output shaft 22, and by meshing the pinion teeth (not shown) with the rack teeth (not shown) of the rack bar 3, the output shaft 22 It is possible to convert the rotational operation of the rack bar 3 into an axial movement of the rack bar 3 and transmit the rotational movement of the rack bar 3.
  • a torque sensor TS is arranged on the outer peripheral side of the steering shaft 2 to detect steering torque inputted to the steering shaft 2 by the driver. This torque sensor TS detects steering torque based on the amount of relative rotational displacement between the input shaft 21 and the output shaft 22.
  • Both ends of the rack bar 3 are linked to left and right steered wheels (not shown) via tie rods 4, 4 and knuckle arms (not shown). That is, the rack bar 3 moves in the axial direction, and as the rack bar 3 moves in the axial direction, the knuckle arms (not shown) are pushed and pulled via the tie rods 4, 4, so that the steered wheels (not shown) are moved. The orientation of is changed. Further, tie rods 4, 4 are connected to both ends of the rack bar 3 via ball joints 40, 40, which are shaft couplings.
  • the vicinity of the axial end of the rack bar 4, that is, the vicinity of the rack end, is covered with rubber boot members 5, 5, and the ball joints 40, 40 are covered by rubber boot members 5, 5. protected from.
  • the boot members 5, 5 have a bellows cylindrical shape that can be expanded and contracted as the rack bar 3 moves in the axial direction, and have one end fixed to the rack bar housing section 13 and the other end fixed to the tie rods 4, 4. By doing so, the ball joints 40, 40 are surrounded.
  • the steering assist mechanism AM includes an electric motor 61 that generates the steering assist force, a control device 62 that controls the drive of the electric motor 61, and a transmission mechanism 63 that transmits the driving force of the electric motor 61 to the rack bar 3.
  • the steering assist mechanism AM moves the rack bar 3 in the axial direction using the driving force of the electric motor 61, which is drive-controlled by the control device 62 based on the detection results of various sensors such as the torque sensor TS and the vehicle speed sensor (not shown). assist.
  • FIG. 2 is a sectional view taken along line AA in FIG. 1, and shows a sectional view of the adjustment mechanism 7 in the steering device.
  • the steering device is disposed at a meshing portion between pinion teeth 220 formed on the steering shaft 2 (output shaft 22) and rack teeth 30 formed on the rack bar 3. It has an adjustment mechanism 7 that adjusts the meshing of the rack teeth 30.
  • the adjustment mechanism 7 includes a rack retainer 71 that supports the rack back surface 31 of the rack bar 3, a coil spring 72 that biases the rack retainer 71 toward the rack bar 3, and a coil spring 72 that holds the coil spring 72 and presses the coil spring 72. and a spring holding member 73 that adjusts the biasing force of the spring.
  • the adjustment mechanism 7 biases the rack bar 3 toward the output shaft 22 based on the biasing force of the coil spring 72 held by the spring holding member 73, which causes the rack retainer 71 that supports the rack back surface 31 of the rack bar 3 This adjusts the meshing of the rack teeth 30 with the pinion teeth 220.
  • the rack retainer 71 is made of a metal material such as an aluminum alloy and has a generally cylindrical shape, and extends in the direction of an axis Y orthogonal to the central axis X of the rack bar 3 inside the retainer accommodating portion 12 of the housing 1. It is housed so that it can be moved along.
  • the rack retainer 71 has a retainer abutting portion that is formed in an axial end facing the rack back surface 31 in the shape of a concave arc groove having a curvature corresponding to the curvature of the rack back surface 31 and that contacts the rack back surface 31. 710.
  • a sliding member 74 made of a material (for example, PTFE resin) having a lower frictional resistance than the rack retainer 71 is attached to the retainer contact portion 710.
  • annular seal holding groove 711 cut out along the circumferential direction is formed on the outer circumferential side of the rack retainer 71.
  • An annular seal member 75 such as a well-known O-ring, which can elastically come into contact with the inner circumferential surface of the retainer accommodating portion 12, is fitted into the seal holding groove 711. That is, by the seal member 75 slidingly contacting the inner circumferential surface of the retainer housing part 12, water and dust entering from the outer open end of the retainer housing part 12 are suppressed from entering the rack bar housing part 13. .
  • the coil spring 72 has a first spring seating part 712 formed in a concave shape at the axial end of the rack retainer 71 opposite to the retainer contact part 710, and a first spring seating part 712 formed in a concave shape at the end of the spring holding member 73 opposite to the rack retainer 71. It is accommodated in a compressed state with a predetermined preload between it and a second spring seating portion 731 formed in a concave shape.
  • the spring holding member 73 has a male threaded portion 730 on the outer circumferential side, and is screwed into a female threaded portion 120 formed inside the outer open end of the retainer accommodating portion 12. That is, by adjusting the amount by which the spring holding member 73 is screwed into the retainer housing portion 12, the amount of compression of the coil spring 72 can be adjusted, and the biasing force of the rack retainer 71 can be adjusted.
  • the spring holding member 73 can maintain the screwing amount of the spring holding member 73 into the retainer accommodating part 12 by screwing the lock nut 76 into the male threaded part 730 exposed from the retainer accommodating part 12.
  • FIG. 3 is a cross-sectional view taken along line BB in FIG. 1, and shows a cross-sectional view near the axial end of the rack bar accommodating portion 13 in the steering device.
  • the rack bar accommodating portion 13 of the housing 1 has a rack bar insertion hole 130 having a cross section corresponding to the outer shape of the rack bar 3.
  • the rack bar insertion hole 130 is formed in a penetrating state along the axial direction of the rack bar 3.
  • the rack bar insertion hole 130 has enlarged diameter portions 131 at both ends in the axial direction that widen in a step shape toward the outside in the axial direction.
  • the enlarged diameter portion 131 has an inner diameter capable of receiving a ball joint 40 (see FIG. 1) provided at an axial end of the rack bar 3, which is a rack end.
  • a step portion 132 is formed between the enlarged diameter portion 131 and the rack bar insertion hole 130, and functions as a restriction portion that restricts movement of the ball joint 40 by coming into contact with the ball joint 40.
  • a rack relief portion 133 is provided to avoid both widthwise ends 301 and 302 of the rack teeth 30 of the rack bar 3 when the rack bar 3 is bent toward the 30 side (Q direction in FIG. 3).
  • the rack relief portion 133 is provided on the opposite side of the retainer accommodating portion 12 across the central axis X of the rack bar 3, and is formed by recessing the outer circumferential surface of the rack insertion hole 130 radially outward, thereby forming a cross section as shown in FIG.
  • the surface (cross section perpendicular to the central axis X of the rack bar 3) is formed to have an arcuate concave shape.
  • FIG. 4 shows an enlarged view of the vicinity of the axial end (the left end in FIG. 1) of the rack bar 3 shown in FIG.
  • the rack bar accommodating portion 13 of the housing 1 has a rack bar insertion hole 130 having a cross section corresponding to the outer shape of the rack bar 3.
  • the rack bar insertion hole 130 is formed in a penetrating state along the axial direction of the rack bar 3.
  • the rack bar insertion hole 130 has enlarged diameter portions 131 at both ends in the axial direction that widen in a step shape toward the outside in the axial direction.
  • the enlarged diameter portion 131 has an inner diameter capable of receiving a ball joint 40 (socket portion 41 to be described later) attached to an axial end portion of the rack bar 3, which is a rack end.
  • a portion between the enlarged diameter portion 131 and the rack bar insertion hole 130 functions as a restriction portion that restricts movement of the ball joint 40 by coming into contact with an end surface (a contact surface 414 to be described later) of the socket portion 41 of the ball joint 40.
  • a stepped portion 132 is formed.
  • the stepped portion 132 has a buffer member receiving portion 134 formed in an inner region facing the ball joint 40 (a contact surface 414 described later) for sandwiching a buffer member 8, which will be described later, between the ball joint 40 and the ball joint 40. .
  • the buffer member receiving portion 134 has an inner diameter smaller than a contact surface 414 of the ball joint 40, which will be described later, and a larger inner diameter than the buffer member 8.
  • the stepped portion 132 has a regulating surface 135 that can come into contact with a contact surface 414 (described later) of the ball joint 40 to regulate the movement of the rack bar 3, and the buffer member receiving portion 134 has a regulating surface 135 that can regulate the movement of the rack bar 3.
  • a predetermined radial gap C1 is secured between the buffer member 8 and the outer peripheral surface thereof.
  • a ball joint 40 which is a shaft joint that connects the rack bar 3 and the tie rod 4 (see FIG. 1), is attached to the axial end of the rack bar 3.
  • the ball joint 40 includes a socket part 41 as a mounting base that is attached to the rack bar 3, and a stud part 43 as a shaft part that is supported via a ball part 42 that is rotatably held by the socket part 41.
  • the socket part 41 is provided at one end in the axial direction, and has a socket body part 411 surrounding the ball part 42, and is provided integrally with the socket main body part 411 at the other end in the axial direction, and is provided at the end in the axial direction of the rack bar 3. It has a screw part 412 to be screwed into.
  • the socket main body part 411 is formed into a cylindrical shape that gradually narrows at the distal end, and is provided with a concave ball receiving part 413 for receiving the ball part 42 therein. Further, the socket main body portion 411 has an outer diameter larger than the inner diameter of the rack bar insertion hole 130.
  • the screw portion 412 is reduced in diameter in a stepped manner with respect to the socket main body portion 411 and has an outer diameter smaller than the outer diameter of the rack bar 3.
  • a male threaded portion 413 is formed on the outer circumferential side of the screw portion 412 and engages with a female threaded hole 32 formed at the axial end of the rack bar 3 .
  • the socket part 41 has a contact surface 414 between the socket main body part 411 and the screw part 412 that can come into contact with the stepped part 132 of the rack bar accommodating part 13 of the housing 1.
  • the contact surface 414 is formed of a flat plane that is generally perpendicular to the central axis X of the rack bar 3. Note that the socket portion 41 is attached to the rack bar 3 with the inner peripheral side of the contact surface 414 abutting against the axial end surface of the rack bar 3.
  • the rack bar 3 has a generally annular buffer member 8 attached to the outer peripheral side of the axial end.
  • the buffer member 8 integrally has a convex portion 83 that protrudes inward in the radial direction, and the convex portion 83 engages with the concave portion 33 that is recessed inward in the radial direction from the outer peripheral surface of the axial end of the rack bar 3. , attached to the rack bar 3.
  • FIG. 5 is an enlarged view of the main part of FIG. 3, showing the state of the buffer member 8 before deformation.
  • FIG. 6 is an enlarged view of the main part of FIG. 3, and shows a state after deformation of the buffer member 8 in the lock end state.
  • the steering shaft 2 (see FIG. 1) side in the axial direction (direction along the central axis X) of the rack bar 3 is referred to as the first end side X1
  • the tie rod 4 ( (see FIG. 1) side is defined as the second end side X2.
  • the buffer member 8 is formed of a predetermined rubber material into a continuous ring shape along the circumferential direction of the rack bar 3.
  • the buffer member 8 includes a thick wall portion 81 having a relatively wide axial width, and a thick wall portion 81 that is narrowed in a stepped shape on the radial inner side of the thick wall portion 81.
  • a thin part 82 having an axial width narrower than the part 82; and a convex part formed on the inner peripheral side of the thin part 82 to protrude toward the rack bar 3 and capable of engaging with the recess 33 provided in the rack bar 3.
  • the buffer member 8 is formed symmetrically with respect to the axial center P of the convex portion 83.
  • the housing 1 includes a buffer member receiving part 134 that receives the end of the buffer member 8 on the first end X1 side at the axial end of the rack bar receiving part 13 and the inner circumferential end of the stepped part 132.
  • the buffer member receiving portion 134 has a first opposing surface 134a that faces the buffer member 8 in the axial direction, and a second opposing surface 134b that faces the buffer member 8 in the radial direction.
  • the inner diameter of the buffer member receiving portion 134 that is, the inner diameter R1 of the second opposing surface 134b is set larger than the outer diameter R2 of the buffer member 8 in an uncompressed state as shown in FIG.
  • a predetermined radial gap C1 is ensured between the thick wall portion 8 (thick wall portion 81) and the buffer member receiving portion 134 (second opposing surface 134b). Note that, as shown in FIG. 6, the radial gap C1 is such that when the buffer member 8 is compressively deformed, the thick portion 81 (third abutment surface 813 to be described later) of the buffer member 8 contacts the second contact surface of the buffer member receiving portion 134. It is desirable that the size is set to a size that allows contact with the opposing surface 134b.
  • the thick portion 81 is provided on the outermost side of the buffer member 8 and is sandwiched between the contact surface 414 of the socket portion 41 of the ball joint 40 and the buffer member receiving portion 134 of the rack bar receiving portion 13 of the housing 1. This provides a buffering effect.
  • the thick portion 81 has a first contact surface 811 that faces and comes into contact with the first opposing surface 134a of the buffer member receiving portion 134, and a second contact surface 811 that faces and comes into contact with the contact surface 414 of the ball joint 40. It has a contact surface 812 and a third contact surface 813 that faces and comes into contact with the second opposing surface 134b of the buffer member receiving portion 134.
  • the first contact surface 811 has a radial width T that is smaller than the radial width Wz of the first opposing surface 134a of the buffer member receiving portion 134. Furthermore, since the buffer member 8 is formed symmetrically with respect to the axial center P, the first contact surface 811 and the second contact surface 812 have approximately the same radial width T. .
  • the third contact surface 813 has an axial width W1 larger than the axial width Wx of the second opposing surface 134b in the uncompressed state shown in FIG.
  • the thin portion 82 is formed by narrowing both sides in the axial direction from the thick portion 81 in a stepped manner.
  • the thin portion 82 has a predetermined axial clearance C2 between the contact surface 414 and the first opposing surface 134a.
  • the axial width W2 of the thin portion 82 is set to approximately half (50%) of the axial width W1 of the thick portion 81 in the uncompressed state.
  • the axial width W2 of the thin portion 82 can be arbitrarily set depending on the axial clearance C2 to be secured between the contact surface 414 and the first opposing surface 134a, such as the specifications of the steering device, for example. It is possible.
  • a tapered reduced width part 84 is formed between the thin part 82 and the thick part 81, in which the axial width W1 of the thick part 81 is gradually reduced toward the inside in the radial direction.
  • the thin part 82 and the thick part 81 are smoothly continuous through a tapered stepped part (tapered reduced width part 84) that is non-perpendicular (non-parallel to the central axis X). It is formed. This suppresses stress concentration at the boundary between the thick portion 81 and the thin portion 82 during elastic deformation, which will be described later.
  • the thin portion 82 has a flat surface 820 that is approximately parallel to the direction of the central axis X of the rack bar 3 on the inner peripheral side where the convex portion 83 is formed.
  • the flat surface 820 is formed so as to be able to come into contact with the outer peripheral surface of the rack bar 3 when the buffer member 8 is in an uncompressed state. In this way, the buffer member 8 is held with the flat surface 820 in contact with the outer circumferential surface of the rack bar 3 in the uncompressed state, thereby preventing the buffer member 8 from tilting when the buffer member 8 is compressively deformed. suppressed.
  • the convex portion 83 has a tapered shape in which the axial width W3 gradually decreases, and is formed in a continuous annular shape along the circumferential direction of the rack bar 3.
  • the convex portion 83 has a first rounded surface 831 and a second tapered surface 832, which are a pair of arcuate surfaces whose axial width W3 is reduced by tapering, and a first rounded surface 831 and a second rounded surface. It has a tip rounded surface 833 that smoothly connects 832.
  • the concave part 33 that the convex part 83 engages with is formed so that the axial width gradually decreases toward the inside in the radial direction, and the groove center Px passing through the bottom part 330 in the axial direction (in FIG. It is formed so as to be asymmetrical with respect to the axial center P of 8).
  • the recess 33 has a first slope 331 facing the first round surface 831, a second slope 332 facing the second round surface 832, and a first slope 331 and a second slope 332. and a bottom surface 333 having an arcuate cross section formed by smoothly connecting the two.
  • first inclined surface 331 and the second inclined surface 332 are formed in a generally planar shape, but the first inclined surface 331 and the second inclined surface 332 have a so-called rounded shape, that is, The cross section shown in FIG. 5 may be formed in a circular arc shape.
  • first inclined surface and the second inclined surface according to the present invention include the above-mentioned round surface (arc surface) in addition to the plane disclosed in the present embodiment.
  • the first inclined surface 331 has a first inclination angle ⁇ 1, which is an inclination angle that roughly corresponds to the first rounded surface 831 of the convex portion 83.
  • the angle of inclination ⁇ 1 corresponds to the angle formed between the plane and the horizontal line H passing through the bottom 330
  • the first inclined surface 331 is a rounded surface (arc surface).
  • the angle formed by the tangent to the rounded surface and the horizontal line H passing through the bottom 330 corresponds to the angle.
  • the first inclined surface 331 is exemplified as having a substantially planar shape.
  • the second inclined surface 332 has a second inclined angle ⁇ 2 that is gentler (smaller) than the first inclined surface 331.
  • the second inclination angle ⁇ 2 corresponds to the angle formed by the plane and the horizontal line H passing through the bottom 330.
  • the surface 332 is a rounded surface (arc surface)
  • the angle between the tangent to the rounded surface and the horizontal line H passing through the bottom 330 corresponds to the angle.
  • the second inclined surface 332 is exemplified as having a generally planar shape.
  • the second inclination angle ⁇ 2 is such that the distance L2 from the center P to the edge of the second inclined surface 332 is approximately twice the distance L1 from the center P to the edge of the first inclined surface 331. It is set to about half (50%) of the first inclination angle ⁇ 1.
  • the buffer member 8 when the buffer member 8 is in an uncompressed state immediately before the lock end, as shown in FIG. and the protrusion 83 of the buffer member 8 is in contact with the bottom 330 of the recess 33, that is, the axial center P of the buffer member 8 and the groove center Px of the recess 33 are aligned, and the outer peripheral side of the rack bar 3 is maintained.
  • the first contact surface 811 of the buffer member 8 comes into contact with the first opposing surface 134a of the buffer member receiving portion 134 of the housing 1 while the axial center P and the groove center Px of the recess 33 are aligned.
  • the thick portion 81 of the buffer member 8 is disposed between the contact surface 414 of the ball joint 40 and the first opposing surface 134a of the buffer member receiving portion 134, as shown in FIG. It is pinched and compressed in the axial direction. Then, the buffer member 8 moves toward the second end side X2 so that the convex portion 83 climbs the second inclined surface 332, and the second rounded surface 832 or tip rounded surface 833 of the convex portion 83 climbs the second inclined surface 332. It will be in contact with.
  • the thick portion 81 expands in the radial direction, and the third contact surface 813 comes into contact with the second opposing surface 134b of the buffer member receiving portion 134.
  • the contact surface 414 of the ball joint 40 comes into contact with the stepped portion 132 of the housing 1 when the buffer member 8 is compressed to the maximum extent. This restricts the axial movement of the first end side X1 of the rack bar 3, resulting in a lock end state.
  • the buffer member 8 is compressively deformed in this way, the collision of the contact surface 414 of the ball joint 40 with the step portion 132 is alleviated.
  • the recess 33 provided on the outer peripheral side of the rack bar 3 is formed symmetrically with respect to the groove center Px, and the protrusion 73 having a shape corresponding to the recess 33 is engaged.
  • the buffer member 8 is fixed to the rack bar 3. Therefore, at the stroke end (lock end) of the rack bar 3, the buffer member 8 has a part of the thick portion 81 that bulges and deforms in the radial direction due to compression deformation in the axial direction. ) and the rack bar 3. This leaves room for improvement in that it becomes difficult to ensure stable buffering characteristics of the buffer member 8.
  • the steering device according to the present embodiment can solve the problems of the conventional steering device by achieving the following effects.
  • the steering device includes a housing 1 formed in a cylindrical shape extending in the vehicle width direction, and regulating portions ( A rack shaft (rack bar 3) whose movement is regulated by contacting the housing 1 with the contact surface 414 of the ball joint 40, a pinion shaft (output shaft 22 of the steering shaft 2) that engages with the rack bar 3, and a drive shaft.
  • a transmission mechanism 63 that transmits the driving force generated by a source (motor 61 in this embodiment) to the rack bar 3;
  • a recess 33 recessed inward in the radial direction of the bar 3 and a buffer member 8 attached to the recess 33 and sandwiched between the regulating portion (abutting surface 414 of the ball joint 40) and the housing 1 at the stroke end of the rack bar 3.
  • the recess 33 has a first inclined surface 331 and a second inclined surface 332 that are asymmetrical on both sides with the bottom 330, which is the most concave, as a border, and the bottom 330
  • the second inclined surface 332 located on the opposite side of the regulating part is the first inclined surface located on the opposite side of the regulating part (the contact surface 414 of the ball joint 40) than the bottom part 330.
  • the angle of inclination is smaller than that of the surface 331.
  • the recess 33 has the first inclined surface 831 and the second inclined surface 832 which are asymmetrical in the axial direction of the rack bar 3, and the second inclined surface 832 is different from the first inclined surface 831. It has a gentler slope. Therefore, when the buffer member 8 is sandwiched between the contact surface 414 of the ball joint 40 and the first opposing surface 134a of the buffer member receiving portion 134 of the housing 1 at the stroke end (lock end) of the rack bar 3, It becomes possible to guide the buffer member 8 to the second inclined surface 832 side.
  • the convex portion 83 floats up the second slope 832, and the second slope rises within the recess 33. It will shift toward the surface 832 side, that is, the side away from the housing 1 (rack bar accommodating portion 13) (see FIG. 6).
  • a part of the thick wall portion 81 which has bulged and deformed in the radial direction due to the compressive deformation in the axial direction of the buffer member 8 is disposed between the housing 1 (rack bar insertion hole 130) and the rack bar 3. It is possible to suppress changes in buffer characteristics due to being sandwiched between the two. As a result, stable buffering characteristics of the buffer member 8 can be ensured.
  • the buffer member 8 is formed symmetrically with respect to the axial center P, and the recess 33 is formed asymmetrically with respect to the groove center Px, thereby preventing the buffer member 8 from floating as described above. structure is constructed. In this configuration, since there is no front and back sides of the buffer member 8, it is possible to suppress the occurrence of incorrect assembly of the buffer member 8 to the rack bar 3.
  • the buffer member 8 has an annular convex portion 83 that can be engaged with the concave portion 33 on the inner circumferential side facing the concave portion 33, and when the convex portion 83 engages with the concave portion 33, It is attached to rack bar 3.
  • the buffer member 8 is attached to the rack bar 3 by the annularly formed convex portion 83 engaging with the concave portion 33. Therefore, the mounting rigidity of the buffer member 8 is increased, and stable buffer characteristics of the buffer member 8 are ensured.
  • the buffer member 8 has a plurality of protrusions 83 that can be engaged with the recess 33 on the inner circumferential side facing the recess 33, and when the plurality of protrusions 83 engage with the recess 33, the rack bar 3 may be attached.
  • the convex part 83 of the buffer member 8 is may be provided intermittently along the circumferential direction, for example, and the buffer member 8 may be attached to the rack bar 3 by engaging the plurality of protrusions 83 with the recesses 33.
  • the buffer member 8 it is possible to attach the buffer member 8 to the rack bar 3 (to engage the protrusion 83 with the recess 33) with a smaller force than when the protrusion 83 is formed in an annular shape.
  • the workability of attaching the member 8 can be improved.
  • the width (axial width W2) of the inner circumferential side (thin wall portion 82) where the convex portion 83 is provided in the buffer member 8 is different from the width (axial width W2) of the buffer member 8 on the outer circumferential side (thick wall portion 81). ) (axial width W1).
  • the axial width W2 of the thin portion 82 of the buffer member 8 is set smaller than the axial width W1 of the thick portion 81. Therefore, when the buffer member 8 is sandwiched between the ball joint 40 (the contact surface 414) and the housing 1 (the first opposing surface 134a of the buffer member receiving portion 134), Compression allowance can be secured. Thereby, more stable buffering characteristics of the buffer member 8 can be ensured compared to the case where the axial width of the buffer member 8 is constant in the radial direction of the rack bar 3.
  • the buffer member 8 has a flat portion 820 on the inner circumferential side where the convex portion 83 is formed, and the flat portion 820 is provided on the outer circumferential side with respect to the convex portion 83.
  • the flat portion 820 is provided on the inner peripheral side of the buffer member 8 and on the outer peripheral side than the convex portion 83. Therefore, at the lock end, when the buffer member 8 is sandwiched between the ball joint 40 (abutting surface 414) and the housing 1 (first opposing surface 134a of the buffer member receiving portion 134), the flat portion 820 is connected to the rack. By coming into contact with the outer peripheral surface of the bar 3, it becomes possible to suppress the tilting of the buffer member 8. Thereby, more stable buffering characteristics of the buffer member 8 can be ensured.
  • the housing 1 (rack bar accommodating portion 13) has a rack relief portion 133 at the end of the rack bar 3 in the axial direction to avoid the rack teeth 30 of the rack bar 3.
  • the rack escape portion 133 is provided at the axial end of the rack bar insertion hole 130 of the rack bar accommodating portion 13 to avoid the rack teeth 30 (widthwise both ends 301, 302). . Therefore, when the rack bar 3 is bent and deformed due to external input, the interference with the rack teeth 30 (both ends 301, 302 in the width direction) is reduced, and the interference from the rack teeth 30 (both ends 301, 302 in the width direction) is reduced. Stress can be distributed in stages.
  • the housing 1 has a retainer accommodating portion 12 that accommodates a rack retainer 71 for supporting the rack bar 3 on the opposite side of the rack relief portion 133 in the radial direction of the rack bar 3.
  • a retainer housing for housing the rack retainer 71 for supporting the rack bar 3 is provided on the opposite side in the radial direction of the rack relief part 133 across the central axis X of the rack bar 3.
  • a section 12 is provided. Therefore, the rack bar 3 can be appropriately supported by the rack retainer 71, and stable buffering characteristics by the buffer member 8 can be ensured.
  • the buffer member 8 when the buffer member 8 is sandwiched between the regulating portion (the contact surface 414 of the ball joint 40) and the housing 1 at the stroke end of the rack bar 3, the outer circumferential surface (the third contact surface 414) surface 813) comes into contact with housing 1 (second opposing surface 134b of buffer member receiving portion 134).
  • the third contact surface 813 of the buffer member 8 contacts the second opposing surface 134b of the buffer member receiving portion 134 of the housing 1. configured to be possible. This restricts elastic deformation of the buffer member 8 toward the outside in the radial direction, thereby ensuring more stable buffer characteristics of the buffer member 8.
  • the recess 33 is formed in a continuous annular shape along the circumferential direction of the rack accommodating part 13.
  • a plurality of convex portions 83 provided on the inner circumferential side of the buffer member 8 may be provided intermittently along the concave portion 33 to engage the convex portions 83 provided on the inner peripheral side of the buffer member 8 .
  • the plurality of recesses 33 at least some of the recesses 33 may be asymmetrical with respect to the groove center Px, that is, the second sloped surface 332 may have a gentler slope than the first sloped surface 331.
  • the present invention when a plurality of recesses 33 are provided, in addition to an aspect in which the second slope surface 332 of all the recesses 33 has a gentler slope than the first slope surface 331, the present invention provides a mode in which the second slope surface 332 of all the recesses 33 has a gentler slope than the first slope surface 331. This includes a mode in which the second inclined surface 332 has a gentler slope than the first inclined surface 331.
  • a housing 1 formed in a cylindrical shape extending in the vehicle width direction;
  • a rack shaft (rack bar 3) whose movement is regulated by the regulation parts (contact surfaces 414 of the ball joint 40) provided at both ends coming into contact with the housing 1;
  • a pinion shaft (steering shaft) which engages with the rack bar 3; 2), a transmission mechanism 63 that transmits the driving force generated by the drive source (motor 61 in this embodiment) to the rack bar 3, and a transmission mechanism 63 that transmits the driving force generated by the drive source (motor 61 in this embodiment) to the rack bar 3, and
  • a plurality of concave portions 33 are provided in parallel in the rack bar 3 and are recessed inward in the radial direction of the rack bar 3, and a restricting portion (abutment surface 414 of the ball joint 40) and the housing 1 are attached to the concave portion 33 at the stroke end of the rack bar 3.
  • a buffer member 8 is sandwiched between the plurality of recesses 33, and some of the recesses 33 are such that, in the axial cross section of the rack bar 3, both sides of the recess 33 are located at the bottom 330, which is the most recessed part.
  • the first inclined surface 331 may have a gentler slope than the first inclined surface 331 located closer to the regulating portion (the contact surface 414 of the ball joint 40) than the first inclined surface 330.
  • the present invention is not limited to the configuration of the above-described embodiments, and can be freely changed according to the specifications of the applied steering device, etc., as long as the configuration can achieve the effects of the present invention.
  • the buffer member 8 can be removed from the housing 1 (rack bar accommodating section 13) in the locked end state.
  • the housing 1 rack bar accommodating section 13
  • the buffer member 8 can be removed from the housing 1 (rack bar accommodating section 13) in the locked end state.
  • the problem is that a part of the thick wall portion 81 that bulges and deforms in the radial direction due to compression deformation of the impact member 8 is caught between the housing 1 (rack bar insertion hole 130) and the rack bar 3. It is determined by the relative relationship between the concave portion 33 and the convex portion 83 of the buffer member 8.
  • the problem that a part of the buffer member 8 is caught between the housing 1 (rack bar insertion hole 130) and the rack bar 3 is due to the inclination angle of the first rounded surface 831 of the convex part 83, not to the recess 33. It is also possible to solve this problem by setting the inclination angle of the second rounded surface 832 relatively small.
  • the relationship between the concave and convex portions of the rack bar 3 and the buffer member 8 may be reversed, and the convex portion is provided on the outer circumferential side of the rack bar 3, and the concave portion is provided on the inner circumferential side of the buffer member 8.
  • the inclined surface of the recess provided on the buffer member 8 side is formed asymmetrically with respect to the bottom of the recess (the center of the groove), and the slope of the outer side (the side far from the housing 1) of the recess is formed asymmetrically. It is sufficient that the inclination angle of the inclined surface on the inner side (the side closer to the housing 1) is set to be gentler than the inclination angle of the surface.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Power Steering Mechanism (AREA)

Abstract

Dans un dispositif de direction selon la présente invention, un évidement (33) présente une première surface inclinée (831) et une seconde surface inclinée (832) qui sont asymétriques dans la direction axiale d'une barre de crémaillère (3), et la seconde surface inclinée (832) présente une pente plus douce que la première surface inclinée (831). Ainsi, lorsqu'un élément d'amortissement (8) est interposé entre un joint à rotule (40) et une partie de stockage de barre de crémaillère (13) d'un boîtier (1) au niveau d'une extrémité de course de la barre de crémaillère (3), l'élément d'amortissement (8) peut être guidé vers le second côté de surface inclinée (832). En conséquence, il est possible d'inhiber un changement de propriétés d'amortissement provoqué par l'interposition, entre la barre de crémaillère (3) et un trou d'insertion de barre de crémaillère (130) du boîtier (1), d'une partie d'une section épaisse (81) de l'élément d'amortissement (8) qui a renflé et s'est déformée dans la direction radiale conjointement avec une déformation par compression dans la direction axiale, et il est possible de garantir des propriétés d'amortissement stables de l'élément d'amortissement (8).
PCT/JP2023/032443 2022-09-15 2023-09-06 Dispositif de direction WO2024058015A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022146650 2022-09-15
JP2022-146650 2022-09-15

Publications (1)

Publication Number Publication Date
WO2024058015A1 true WO2024058015A1 (fr) 2024-03-21

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008024076A (ja) * 2006-07-19 2008-02-07 Toyota Motor Corp ステアリング装置
JP2017077872A (ja) * 2015-10-22 2017-04-27 株式会社ジェイテクト ダンパ装置及びステアリング装置
WO2019031100A1 (fr) * 2017-08-10 2019-02-14 日立オートモティブシステムズ株式会社 Dispositif de direction
WO2020017503A1 (fr) * 2018-07-20 2020-01-23 日本精工株式会社 Ensemble boîtier de direction de type à crémaillère et à pignon
JP2020117174A (ja) * 2019-01-28 2020-08-06 日立オートモティブシステムズ株式会社 ステアリング装置、及びステアリング装置の製造方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008024076A (ja) * 2006-07-19 2008-02-07 Toyota Motor Corp ステアリング装置
JP2017077872A (ja) * 2015-10-22 2017-04-27 株式会社ジェイテクト ダンパ装置及びステアリング装置
WO2019031100A1 (fr) * 2017-08-10 2019-02-14 日立オートモティブシステムズ株式会社 Dispositif de direction
WO2020017503A1 (fr) * 2018-07-20 2020-01-23 日本精工株式会社 Ensemble boîtier de direction de type à crémaillère et à pignon
JP2020117174A (ja) * 2019-01-28 2020-08-06 日立オートモティブシステムズ株式会社 ステアリング装置、及びステアリング装置の製造方法

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