JP2009191936A - Extensible shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extensible shaft and a steering system having the extensible shaft facilitating the assembly work of an elastically deformable sleeve and an energizing member to a male shaft, allowing the presence of the assembled energizing member to be externally confirmed, and effectively applying the energizing force of a spring as a previous load to the elastically deformable sleeve interposed in a clearance between the male shaft and a female shaft. <P>SOLUTION: Partial sleeves 71 with plate springs 84 connected beforehand thereto are assembled to the male shaft 12B. Assembly work is thereby facilitated, and an assembling time is reduced. When the partial sleeve 71 and the plate spring 84 are connected, a flat part 841 and a stepped part 842 of the plate spring 84 are exposed to the outer periphery 7142 of a connecting sleeve part 714. The presence of the assembled plate spring 84 can thereby be externally confirmed, and a failure to assemble the plate spring 84 can be easily prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a telescopic shaft, in particular, a telescopic shaft capable of transmitting rotational torque and relatively moving in the axial direction, for example, a telescopic shaft such as an intermediate shaft or a steering shaft, and a steering device having a telescopic shaft.

  In the steering device, a telescopic shaft connected to be able to transmit rotational torque and to be relatively movable in the axial direction is incorporated in an intermediate shaft, a steering shaft, or the like. That is, when the universal joint is fastened to the pinion shaft that meshes with the rack shaft of the steering gear, the intermediate shaft needs to have a telescopic function in order to be contracted and then fitted to the pinion shaft and fastened.

  In addition, the steering shaft transmits the steering force of the steering wheel to the wheel, and the position of the steering wheel needs to be adjusted in the axial direction according to the physique and driving posture of the driver. .

  In order to achieve good operability of the steering wheel with such a telescopic shaft, the backlash in the rotational direction between the relatively slidable male shaft and female shaft is small, and the male shaft and female shaft The axial sliding resistance with the shaft needs to be maintained at a predetermined sliding resistance over a long period of time. Such telescopic shafts are disclosed in Patent Document 1 and Patent Document 2.

  The telescopic shaft of Patent Document 1 is a male shaft having a non-circular outer periphery, a female shaft having a non-circular inner periphery, and between the outer periphery of the male shaft and the inner periphery of the female shaft, and integrally formed with the male shaft. It is composed of two wedge pieces that are inserted into a gap between the two sliding bushes and are urged in a direction away from each other by a spring.

  In the telescopic shaft of this Patent Document 1, since the number of parts is large, the manufacturing cost is increased, and manufacturing errors of parts are piled up, so that it is difficult to obtain play and sliding resistance in a predetermined rotation direction. Further, since the sliding bush is arranged at both end portions in the axial direction of the male shaft and the wedge piece is arranged inside thereof, the both end portions in the axial direction of the fitting portion of the male shaft and the female shaft are Preload by wedge piece does not work. Accordingly, the elimination of the play in the bending direction (moment direction) is insufficient, and if the spring force is increased in order to eliminate the play in the bending direction (moment direction), the sliding resistance becomes excessive.

  The telescopic shaft of Patent Document 2 is inserted into a male shaft having a non-circular outer periphery, a female shaft having a non-circular inner periphery, and an inclined gap between the outer periphery of the male shaft and the inner periphery of the female shaft. It is composed of a wedge-shaped member that is elastically deformable. The wedge-shaped member is annularly formed integrally and inserted in a gap between the outer periphery of the male shaft and the inner periphery of the female shaft by a leaf spring and a hinge for applying preload. In the telescopic shaft of this Patent Document 2, since many rust-like members, leaf springs, and hinges are integrally formed in an annular shape, it is necessary to form them with high accuracy, resulting in an increase in manufacturing cost. .

  Further, in the telescopic shaft of Patent Document 2, since the wedge-shaped member is integrally formed in an annular shape, a part of the spring force that applies preload to the wedge-shaped member is consumed as a force for bending the hinge. Therefore, the urging force of the leaf spring cannot be used effectively as the pre-pressure of the wedge-shaped member.

  In addition, when there is a temperature change or a humidity change, the wedge-shaped member formed of a synthetic resin causes expansion or contraction. However, in the telescopic shaft of Patent Document 2, since the wedge-shaped member is integrally formed in an annular shape, the wedge-shaped member cannot move smoothly along the inclined gap by the amount of expansion or contraction, The preload varies, and the axial sliding resistance between the male shaft and the female shaft varies.

Japanese Patent Laid-Open No. 5-116633 US Pat. No. 5,460,574

  The present invention makes it easy to assemble the elastically deformable sleeve and the urging member to the male shaft, the presence or absence of the assembled urging member can be confirmed in appearance, and the male shaft can be used even if there is a change in temperature or humidity. The fluctuation of the sliding resistance between the female shaft and the female shaft is small, and the biasing force of the spring effectively acts as a preload on the elastically deformable sleeve inserted in the gap between the male shaft and the female shaft. It is an object of the present invention to provide a telescopic shaft and a steering device having the telescopic shaft.

  The above problem is solved by the following means. That is, the first invention has a male shaft having a non-circular outer peripheral shape, and a non-circular inner peripheral shape that is fitted on the outer periphery of the male shaft so as to be capable of relative movement in the axial direction and to transmit rotational torque. A female shaft is formed in a gap between the non-circular outer circumference and the non-circular inner circumference, and is inserted into the plurality of inclined gaps and the inclined gaps whose intervals change at a predetermined inclination. It has an elastically deformable inclined sleeve that always contacts both the circular inner periphery and the non-circular outer periphery of the male shaft, and a plurality of them are arranged in the gap between the non-circular inner periphery and the non-circular outer periphery. The partial sleeve is formed separately from the partial sleeve in the axial direction and is formed as a separate part from the pair of through holes penetrating from the inner periphery to the outer periphery of the partial sleeve. The above through hole from the outer periphery The other end is inserted into the inner periphery of the partial sleeve from the outer periphery of the partial sleeve through the other of the through holes, and the central portion in the axial direction is Exposed to the outer periphery of the partial sleeve and coupled to the partial sleeve, and both ends thereof are inserted into a gap between the non-circular outer periphery and the inner periphery of the partial sleeve, so that the inclined sleeve portion is the largest gap of the inclined gap. The telescopic shaft is characterized in that it has a biasing member that biases from the portion side toward the minimum gap portion side and applies a preload to the partial sleeve.

  According to a second invention, in the telescopic shaft of the first invention, the partial sleeve is inserted in a gap between the non-circular outer periphery and the non-circular inner periphery, and the adjacent inclined sleeve portion is inserted. The telescopic shaft is characterized in that it has a connecting sleeve portion for connecting radially outer ends, and the pair of through holes are formed in the connecting sleeve portion.

  According to a third invention, in the telescopic shaft of the second invention, the engaging portion formed on the connecting sleeve portion engages with the urging member, and the urging member is axially moved with respect to the partial sleeve. The telescopic shaft is characterized in that the relative movement is impossible.

  According to a fourth aspect of the invention, in the telescopic shaft of the third aspect of the invention, the engaging portion is formed of the through-hole that engages with a radial step formed on both axial ends of the biasing member. The telescopic shaft is characterized by being side surfaces on both end sides in the axial direction.

  A fifth aspect of the present invention is the telescopic shaft according to the third aspect, wherein the engaging portion is an engaging protrusion that engages with an engaging hole formed in the biasing member. It is.

  According to a sixth aspect of the invention, in the telescopic shaft of the third aspect, the engaging portion is engaged with side surfaces on both end sides in the axial direction of the wide portion formed at a substantially central portion in the axial direction of the biasing member. In addition, the telescopic shaft is a step portion on the center side of the through hole having a narrower groove width than the wide portion.

  According to a seventh invention, in the telescopic shaft of the first invention, the male shaft is in contact with both axial ends of the partial sleeve and is relatively movable in a direction perpendicular to the axial direction of the male shaft. In addition, a locking portion for locking the partial sleeve to the male shaft is formed so as not to be relatively movable in the axial direction of the male shaft, and both axial ends of the urging member abut against the locking portion. Thus, the urging member is locked so as not to move in the axial direction.

  In an eighth aspect of the telescopic shaft according to any one of the first to seventh aspects, a flat portion substantially parallel to the axial direction is formed at a substantially central portion in the axial direction of the biasing member, The telescopic shaft is characterized in that arc-shaped portions that are curved toward the radially inner side are formed at both ends of the urging member toward the both ends in the axial direction.

  A ninth aspect of the invention is the telescopic shaft according to the eighth aspect of the invention, wherein the biasing member is a leaf spring.

  A tenth aspect of the invention is a steering device having the telescopic shaft of any one of the first to ninth aspects.

  In the telescopic shaft and the steering device of the present invention, a male shaft having a non-circular outer peripheral shape, and a non-circular inner periphery that is externally fitted to the outer periphery of the male shaft so as to be capable of relative movement in the axial direction and to transmit rotational torque A female shaft formed in a gap between a female shaft having a shape, a non-circular outer circumference and a non-circular inner circumference, the intervals changing at a predetermined inclination, and the inclined gap. The elastically deformable inclined sleeve portion that always contacts both the non-circular inner periphery of the male shaft and the non-circular outer periphery of the male shaft is disposed in a plurality of spaces between the non-circular inner periphery and the non-circular outer periphery. A partial sleeve, a pair of through holes formed in the partial sleeve so as to be spaced apart in the axial direction, penetrating from the inner periphery to the outer periphery of the partial sleeve, and the biasing member formed as a separate part from the partial sleeve, One end penetrates from the outer periphery of the partial sleeve. It is inserted into the inner periphery of the partial sleeve via one of the holes, and the other end is inserted from the outer periphery of the partial sleeve to the inner periphery of the partial sleeve via the other of the through holes. It is exposed to the outer periphery of the partial sleeve and joined to the partial sleeve, and both ends thereof are inserted into the gap between the noncircular outer periphery and the inner periphery of the partial sleeve, so that the inclined sleeve portion is located from the maximum gap portion side of the inclined gap. The preload is applied to the partial sleeve by urging toward the minimum gap portion side.

  Therefore, it is easy to assemble the sleeve and the urging member to the male shaft, and the presence or absence of the urging member can be confirmed by the appearance, so that it is possible to prevent forgetting to assemble the urging member, and to change the temperature and humidity. Even if there is, the fluctuation of the sliding resistance between the male shaft and the female shaft is small, and the urging force of the urging member is applied to the elastically deformable sleeve inserted in the gap between the male shaft and the female shaft. It works effectively as a preload.

  Embodiments 1 to 4 of the present invention will be described below with reference to the drawings.

  FIG. 1 shows the entire steering apparatus according to the first embodiment of the present invention, and is a side view with a part cut, showing an embodiment applied to an electric power steering apparatus having a steering assisting portion. FIG. 2 is a longitudinal sectional view of the main part of FIG.

  FIG. 3 shows a telescopic shaft according to the first embodiment of the present invention, and is a perspective view showing a state before the partial sleeve of the first embodiment is attached to the male shaft and the female shaft is externally fitted. 4 is an AA enlarged cross-sectional view of FIG. 2, showing a state in which the partial sleeve of Example 1 is attached to the male shaft, and the female shaft is externally fitted to the outer periphery of the partial sleeve.

  5A and 5B show a partial sleeve alone according to the first embodiment of the present invention, in which FIG. 5A is a plan view of the partial sleeve, and FIG. 6 (1) is a view taken along the arrow P in FIG. 5 (2), FIG. 6 (2) is a view taken along the arrow Q in FIG. 5 (2), and FIG. 6 (3) is a cross-sectional view taken along the line CC in FIG. FIG. 6 and FIG. 6 (4) are DD sectional views of FIG. 5 (2). FIG. 7 is a perspective view showing a single plate spring according to the first embodiment of the present invention.

  FIG. 8 shows a state in which a leaf spring is assembled to the partial sleeve according to the first embodiment of the present invention, wherein (1) is a plan view and (2) is an EE sectional view of (1). 9 (1) is a view taken in the direction of the arrow R in FIG. 8 (2), and FIG. FIG. 10 is an explanatory diagram showing a procedure for assembling a leaf spring to the partial sleeve according to the first embodiment of the present invention. FIG. 11 is a longitudinal sectional view showing a state where the partial sleeve according to the first embodiment of the present invention is assembled to the male shaft.

  As shown in FIGS. 1 to 2, the steering device having the telescopic shaft according to the first embodiment of the present invention includes a steering shaft 12 on which a steering wheel 11 can be mounted on the rear side of the vehicle body (the right side in FIGS. 1 and 2), A steering column 13 inserted through the steering shaft 12, an assist device (steering assisting portion) 20 for applying auxiliary torque to the steering shaft 12, and a vehicle body front side of the steering shaft 12 (left side in FIGS. 1 and 2). And a steering gear 30 connected through a rack / pinion mechanism (not shown).

  The steering shaft 12 is configured by combining an outer shaft (hereinafter referred to as a female shaft) 12A and an inner shaft (hereinafter referred to as a male shaft) 12B so that rotational torque can be transmitted and relative displacement in the axial direction can be achieved.

  That is, as shown in FIGS. 2 to 4, a plurality of axial ridges 51 are formed on the outer periphery of the male shaft 12B on the rear side of the vehicle body, and a plurality of axial directions are formed on the inner periphery of the female shaft 12A on the front side of the vehicle body. The groove 41 is formed at the same phase position as the axial ridge 51. The axial ridge 51 of the male shaft 12B and the axial groove 41 of the female shaft 12A are externally fitted with a predetermined gap so as to be able to transmit rotational torque and be relatively displaceable in the axial direction. ing. Therefore, the engaging portion of the female shaft 12A and the male shaft 12B can slide relative to each other at the time of collision, so that the overall length can be shortened.

  The cylindrical steering column 13 inserted through the steering shaft 12 combines an outer column 13A and an inner column 13B so as to be telescopically movable. That is, when an impact in the axial direction is applied at the time of a collision, a so-called collapsible structure is formed in which the entire length of the steering column 13 is reduced while absorbing energy due to the impact.

  The vehicle body front side end portion of the inner column 13B is press-fitted and fixed to the vehicle body rear side end portion of the gear housing 21. Further, the vehicle body front side end portion of the male shaft 12B is passed through the inside of the gear housing 21, and is coupled to the vehicle body rear side end portion of the input shaft 22 of the assist device 20.

  That is, a large diameter shaft portion 121B is formed on the vehicle body front side (left side in FIG. 2) of the male shaft 12B, and a small diameter shaft portion 122B is formed on the vehicle body front side of the large diameter shaft portion 121B. The small-diameter shaft portion 122B is press-fitted and coupled to an inner diameter hole 221 formed on the rear side of the vehicle body (right side in FIG. 2) of the input shaft 22 of the assist device 20, and the axial position of the input shaft 22 and the male shaft 12B. Is fixed.

  The steering column 13 is supported by a support bracket 14 at a middle portion thereof on a part of the vehicle body 18 such as a lower surface of the dashboard. Further, a locking portion (not shown) is provided between the support bracket 14 and the vehicle body 18, and when an impact in a direction toward the front side of the vehicle body is applied to the support bracket 14, the support bracket 14 is locked to the locking bracket 14. It moves away from the vehicle and moves to the front side of the vehicle.

  The upper end portion of the gear housing 21 is also supported on a part of the vehicle body 18. In the case of this embodiment, by providing a tilt mechanism and a telescopic mechanism, the position of the steering wheel 11 in the longitudinal direction of the vehicle body and the height position can be freely adjusted. Such a tilt mechanism and a telescopic mechanism are well known in the art and are not characteristic features of the present invention, and thus detailed description thereof is omitted.

  The output shaft 23 protruding from the end face on the vehicle body front side of the gear housing 21 is connected to the rear end portion of the male intermediate shaft 16 </ b> A of the intermediate shaft 16 via the universal joint 15. Further, the input shaft 31 of the steering gear 30 is connected to the front end portion of the female intermediate shaft 16B of the intermediate shaft 16 via another universal joint 17.

  The male intermediate shaft 16A is coupled to the female intermediate shaft 16B so as to be relatively movable in the axial direction and to transmit rotational torque. A pinion (not shown) is formed at the front end of the input shaft 31. A rack (not shown) meshes with the pinion, and the rotation of the steering wheel 11 moves the tie rod 32 to steer a wheel (not shown).

  As shown in FIG. 2, an input shaft 22 and an output shaft 23 are rotatably supported by bearings 29A, 29B, and 29C on the same axis in the gear housing 21 of the assist device 20, and the input shaft 22 and the output shaft 23 are connected by a torsion bar 24. A worm wheel 25 is attached to the output shaft 23, and a worm 27 is engaged with the worm wheel 25. A case 261 of the electric motor 26 is fixed to the gear housing 21, and a worm 27 is coupled to a rotating shaft (not shown) of the electric motor 26.

  In addition, a torque sensor 28 that detects torsion of the torsion bar 24 is provided around an intermediate portion of the input shaft 22. The torque sensor 28 detects the direction and magnitude of torque applied from the steering wheel 11 to the steering shaft 12. In response to this detection signal, the electric motor 26 is driven, and an auxiliary torque is generated at a predetermined magnitude in a predetermined direction on the output shaft 23 via a speed reduction mechanism including a worm 27 and a worm wheel 25.

  As shown in FIGS. 2 to 4, the telescopic shaft according to the first embodiment of the present invention is applied to a connecting portion between the female shaft 12 </ b> A and the male shaft 12 </ b> B of the steering shaft 12. The front side (left side in FIG. 2) of the female shaft 12A is externally fitted and connected to the rear side (right side in FIG. 2) of the male shaft 12B.

  As shown in FIG. 4, the female shaft 12A is formed in a hollow cylindrical shape, and the axial groove 41 is equidistant from the inner periphery of the female shaft 12A over the entire length of the expansion / contraction stroke, radially from the axis 19 of the female shaft 12A. Three are formed at intervals of 120 degrees. Each axial groove 41 has side surfaces 411 and 411 formed at an angle θ with respect to three center lines 193, 193 and 193 passing through the axis 19.

  An interval between the side surfaces 411 and 411 constituting one axial groove 41 becomes narrower toward the radially outer side. Further, the radially outer ends of the side surfaces 411 and 411 are smoothly connected to an arcuate bottom surface 412 that protrudes outward, and each axial groove 41 has a cross section perpendicular to the axis by the side surfaces 411 and 411 and the bottom surface 412. Is formed in a substantially U-shape. The radially inner ends of the side surfaces 411 and 411 are smoothly connected to the radially inner ends of the adjacent side surfaces 411 and 411 by an arc-shaped connecting surface 414 that protrudes inward.

  Further, three axial ridges 51 are formed on the male shaft 12B radially from the axis 19 at the same phase position as the axial groove 41 at equal intervals (120 degree intervals).

  The axial ridge 51 has side surfaces 511 and 511 that are parallel to the three center lines 193, 193, and 193, respectively. Therefore, the space | interval between the side surface 511 and the side surface 511 which comprise the one axial direction protruding item | line 51 is constant, and is formed in parallel toward the radial direction outer side.

  Further, the radially outer ends of the side surfaces 511 and 511 are connected to a linear top surface 512 orthogonal to the center line 193, and the axial ridges 51 are formed by the side surfaces 511 and 511 and the top surface 512. The cross section perpendicular to the axis is formed in a substantially U-shape. The radial inner ends of the side surfaces 511 and 511 are connected to the radial inner ends of the adjacent side surfaces 511 and 511 by an arc-shaped connecting surface 514 that protrudes inward.

  Accordingly, the inclined gap 62 between the side surfaces 511 and 511 of the axial ridge 51 of the male shaft 12B and the side surfaces 411 and 411 of the axial groove 41 of the female shaft 12A becomes narrower toward the radially outer side. Is formed.

  As shown in FIG. 4, three partial sleeves 71 formed of an elastic member are inserted in a gap between the outer periphery of the male shaft 12B and the inner periphery of the female shaft 12A. In the first embodiment, three partial sleeves 71 of the same part are used by being externally fitted to the outer periphery of the three axial ridges 51 of the male shaft 12B. The partial sleeve 71 includes two elements, an inclined sleeve portion 712 and a connecting sleeve portion 714.

  That is, the inclined sleeve portions 712 and 712 are inserted into the inclined gaps 62 and 62, respectively, and an arc-shaped connecting sleeve portion 714 is integrally formed at the radially outer ends of the inclined sleeve portions 712 and 712. . The connecting sleeve portion 714 is inserted into the outer arc-shaped gap 64 between the arc-shaped bottom surface 412 and the linear top surface 512 and is connected to the radially outer ends of the adjacent inclined sleeve portions 712 and 712. Yes.

  As shown in FIGS. 3, 5 (1), and 6 (1) to 6 (3), the inclined sleeve portions 712 and 712 are formed with a groove-like grease reservoir 7123 on the outer circumferences 7122 and 7122 thereof. Has been. Nine grease reservoirs 7123 are formed at equal intervals over the entire length of the inclined sleeve portions 712 and 712 in the axial direction. Therefore, grease can be effectively supplied to the sliding surface between the outer periphery 7122 of the inclined sleeve portion 712 and the side surface 411 of the female shaft 12A.

  The connecting sleeve portion 714 has through holes 72 and 73 formed at two locations. The through holes 72 and 73 are formed so as to penetrate from the inner periphery 7141 of the connection sleeve portion 714 to the outer periphery 7142 at positions equidistant from the axial center portion of the connection sleeve portion 714 toward both ends in the axial direction. Yes. The through holes 72 and 73 are rectangular, and the left and right groove widths W2 of the through holes 72 and 73 are slightly larger than the left and right widths W3 of the leaf springs 84 (see FIGS. 4, 7, and 8) as biasing members. Largely formed.

  When the partial sleeve 71 is externally fitted to the outer periphery of the axial protrusion 51 of the male shaft 12B, the leaf spring 84 is placed between the outer peripheral top surface 512 of the male shaft 12B and the inner periphery 7141 of the connecting sleeve portion 714. To be inserted.

  That is, as shown in FIGS. 5 and 6, a rectangular groove 713 is formed on the inner periphery 7141 of the connecting sleeve portion 714. The rectangular groove 713 extends from both ends of the connecting sleeve portion 714 in the axial direction to the center side in the axial direction, and is formed to side surfaces 721 and 731 on the center side in the axial direction of the through holes 72 and 73.

  The left and right groove width W1 of the rectangular groove 713 is slightly larger than the left and right width W3 of the leaf spring 84 (see FIGS. 7 and 9). The groove depth δ1 ( 6 (2)) is formed slightly larger than the plate thickness T1 of the leaf spring 84 (see FIG. 7).

  A rectangular groove 715 is formed on the outer periphery 7142 of the connecting sleeve portion 714 between the central side surface 721 of the through hole 72 and the central side surface 731 of the through hole 73. The left and right groove widths W4 of the rectangular grooves 715 are formed to be the same as the left and right groove widths W1 of the rectangular grooves 713. The groove depth δ2 (see FIG. 6 (3)) at the shallowest portion of the rectangular groove 715 is formed to be slightly larger than the plate thickness T1 (see FIG. 7) of the leaf spring 84.

  The leaf spring 84 is a separate part from the partial sleeve 71 and is made of thin spring steel. As shown in FIGS. 7 and 8, the leaf spring 84 has an arcuate shape as a whole, is formed symmetrically from the axial center to the both axial ends (end face side), and sequentially from the axial center. , Flat portions 841, stepped portions 842 and 842, flat portions 843 and 843, and arc-shaped portions 844 and 844 are formed.

  That is, the leaf spring 84 has a linear flat portion 841 at the central portion in the axial direction. As shown in FIG. 8, in a state where the flat portion 841 is placed on the groove bottom surface 7151 of the rectangular groove 715, the flat portion 841 extends from the center portion in the axial direction to the side surfaces 722 on both end sides in the axial direction of the through holes 72 and 73. It extends to just before 732. The flat portion 841 is bent at an angle of 45 degrees radially inward immediately before the side surfaces 722 and 732 on both end sides to form step portions 842 and 842, and along the groove bottom surface 7131 of the rectangular groove 713 in the axial direction. Flat portions 843 and 843 extending to both end sides of the plate are formed.

  The flat portions 843 and 843 slightly extend linearly on both end sides in the axial direction along the groove bottom surface 7131 of the rectangular groove 713, and then arc-shaped portions 844 and 844 are formed. The arc-shaped portions 844 and 844 are arc-shaped convex toward the outer side in the radial direction, and are curved in a direction approaching the inner side in the radial direction toward the both end sides in the axial direction.

  In order to couple the leaf spring 84 to the partial sleeve 71, as shown in FIG. 10 (1), an end portion 8441 of one arcuate portion 844 of the leaf spring 84 is connected to a connecting sleeve as shown by a white arrow. The portion 714 is inserted into one through hole 72 from the inner periphery 7141. When the leaf spring 84 is further pushed in, the arc-shaped portion 844 is curved in a direction closer to the inner side in the radial direction toward the end face side in the axial direction, and therefore, as shown in FIG. The end portion 8441 is smoothly inserted into the other through hole 73.

  When the leaf spring 84 is further pushed in, the end portion 8441 of the arc-shaped portion 844 moves toward the end surface side in the axial direction along the groove bottom surface 7131 of the rectangular groove 713, and the flat portion 841 is formed into the rectangular groove as shown in FIG. 715 is placed on the groove bottom surface 7151, and both flat portions 843 and 843 are in contact with the groove bottom surfaces 7131 and 7131 of the rectangular groove 713.

  Further, even if a force that causes the leaf spring 84 to shift in the axial direction with respect to the partial sleeve 71 is applied, the stepped portions 842 and 842 of the leaf spring 84 have side surfaces 722 on both end sides in the axial direction of the through holes 72 and 73. The leaf spring 84 abuts against the partial sleeve 71 so as not to move in the axial direction. In other words, the side surfaces 722 and 732 on both ends constitute an engaging portion that makes the leaf spring 84 relatively unmovable relative to the partial sleeve 71 in the axial direction.

  When the partial sleeve 71 and the leaf spring 84 are coupled, the flat portion 841 and the step portions 842 and 842 of the leaf spring 84 are exposed on the outer periphery 7142 of the connecting sleeve portion 714, so that the presence or absence of the assembled leaf spring 84 is determined by the appearance. This makes it easy to prevent forgetting to attach the leaf spring 84.

  Therefore, as shown in FIGS. 3 and 11, when the partial sleeve 71 to which the leaf spring 84 is coupled is externally fitted to the outer periphery of the male shaft 12B, the connecting portion between the connecting sleeve portion 714 and the inclined sleeve portion 712 is formed thin. Therefore, the partial sleeve 71 is easily elastically deformed at the connecting portion, and the sleeve 71 can be easily fitted on the outer periphery of the male shaft 12B.

  Therefore, the leaf spring 84 is inserted between the top surface 512 of the outer periphery of the male shaft 12B and the groove bottom surface 7131 of the connecting sleeve portion 714, and the partial sleeve 71 faces outward in the radial direction (radial direction). Energize. The leaf spring 84 is in contact with the male shaft 12B and the connecting sleeve portion 714 at the five solid ellipses J1 to J5 in FIG. 11, and the line connecting the five contact points is substantially M-shaped. The biasing force of the leaf spring 84 can be reliably applied to the partial sleeve 71.

  FIG. 3 shows a state in which one partial sleeve 71 to which the leaf spring 84 is coupled is externally fitted to the outer periphery of the male shaft 12B, but the remaining two partial sleeves 71 are also externally fitted to the outer periphery of the male shaft 12B. .

  Subsequently, as shown in FIG. 4, the female shaft 12A is externally fitted to the male shaft 12B on which the three partial sleeves 71 are externally fitted. Then, since the outer periphery of the inclined sleeve portion 712 has a predetermined tightening allowance with respect to the side surface 411 of the female shaft 12A, when the female shaft 12A is externally fitted to the male shaft 12B against the tightening allowance, the inclined sleeve The part 712 (partial sleeve 71) moves inward in the radial direction (radial direction).

  When the inclined sleeve portion 712 moves inward in the radial direction (radial direction), the leaf spring 84 is strongly compressed between the top surface 512 of the male shaft 12B and the groove bottom surface 7131 of the connecting sleeve portion 714. As a result, each partial sleeve 71 is urged outward in the radial direction (radial direction) by the urging force of the leaf spring 84, and the inclined sleeve portion 712 moves from the maximum gap portion side of the inclined gap 62 to the minimum gap portion side. Is pressed toward. Therefore, there is no backlash between the male shaft 12B and the female shaft 12A, and a predetermined preload is applied between the male shaft 12B and the female shaft 12A.

  When the vehicle body longitudinal direction position of the steering wheel 11 is adjusted in this state, the outer column 13A moves telescopically with respect to the inner column 13B, and the female shaft 12A slides in the axial direction with respect to the male shaft 12B.

  By sliding in the axial direction of the female shaft 12A, the outer periphery of the inclined sleeve portion 712 slides while always contacting the side surface 411 of the female shaft 12A. Accordingly, the outer periphery of the inclined sleeve portion 712 is gradually worn by the frictional force at the time of sliding, but the direction in which the inclined sleeve portion 712 is pressed against the inclined gap 62 by the elastic force of the leaf spring 84. Therefore, the female shaft 12A slides relative to the male shaft 12B without rattling.

  The flat portion 841 and the step portion 842 of the leaf spring 84 are exposed on the outer periphery 7142 of the connecting sleeve portion 714. However, the groove depth δ2 (see FIG. 6 (3)) of the rectangular groove 715 in which the flat portion 841 and the stepped portion 842 are accommodated is formed slightly larger than the plate thickness T1 of the leaf spring 84. Accordingly, the flat portion 841 and the stepped portion 842 of the leaf spring 84 do not contact the bottom surface 412 of the axial groove 41 of the female shaft 12A, and when the female shaft 12A slides in the axial direction with respect to the male shaft 12B. , Do not get in the way.

  Further, since each partial sleeve 71 can be individually relatively moved in a direction (radial direction) orthogonal to the axial direction of the male shaft 12B, all the elastic force of the leaf spring 84 is transmitted to the partial sleeve 71, which is effective as a preload. It works in the same way.

  As a result, even if the outer periphery of the inclined sleeve portion 712 is worn, the elastic force of the leaf spring 84 moves from the maximum gap portion of the inclined gap 62 toward the minimum gap portion by the amount of wear of the outer periphery of the inclined sleeve portion 712. The inclined sleeve portion 712 (partial sleeve 71) is further pressed. Therefore, a predetermined urging force always acts on the inclined sleeve portion 712.

  When there is a temperature change or a humidity change, the partial sleeve 71 formed of synthetic resin causes expansion or contraction. However, since the adjacent partial sleeves 71 are relatively movable in a direction (radial direction) perpendicular to the axial direction of the male shaft 12B, they can move smoothly along the inclined gap 62 by the amount of expansion or contraction, There is no fluctuation of the preload, and the axial sliding resistance between the male shaft 12B and the female shaft 12A is kept constant.

  When the steering wheel 11 is rotated and a wheel (not shown) is steered, rotational torque acts between the female shaft 12A and the male shaft 12B. Since the wedge angle θ of the inclined gap 62 is set to be equal to or less than the friction angle of the inclined sleeve portion 712, the inclined sleeve portion 712 does not move.

  Accordingly, there is no backlash between the male shaft 12B and the female shaft 12A, and a state in which a predetermined preload is applied between the male shaft 12B and the female shaft 12A is maintained, and the inclined sleeve portion 712 is maintained. Rotational torque is transmitted from the female shaft 12A to the male shaft 12B between the outer periphery and the side surface 411 of the female shaft 12A.

  The material of the partial sleeve 71 is preferably molded from natural rubber, synthetic rubber, or a mixture of natural rubber and synthetic rubber. The material of the partial sleeve 71 is a material in which at least one solid lubricant of molybdenum disulfide, graphite, or fluorine compound is contained in natural rubber, synthetic rubber, or a mixture of natural rubber and synthetic rubber. It is preferable to mold by injection molding, and it can be molded by injection molding.

  The material of the partial sleeve 71 is based on at least one polymer material selected from polytetrafluoroethylene, phenol resin, acetal resin, polyimide resin, polyamideimide resin, polyethersulfone resin, and polyphenylene sulfide resin. It is preferable to mold with a material containing at least one solid lubricant of molybdenum sulfide, graphite and fluorine compound, and it can be molded by injection molding.

  The material of the partial sleeve 71 is based on at least one polymer material of polytetrafluoroethylene, phenol resin, acetal resin, polyimide resin, polyamide imide resin, polyether sulfone resin, polyphenylene sulfide resin, and carbon. It is preferable to mold with a material containing at least one of fiber and carbon beads, and it can be molded by injection molding.

  In the first embodiment, since the partial sleeve 71 to which the leaf spring 84 is previously coupled is assembled to the male shaft 12B, the assembling work is easy and the assembling time is shortened. In addition, since the presence or absence of the assembled leaf spring 84 can be confirmed by appearance, it becomes easy to prevent forgetting to attach the leaf spring 84.

  Furthermore, if the leaf spring 84 and the partial sleeve 71 are formed as separate parts, it becomes possible to manufacture each part with high accuracy compared to the case where the leaf spring 84 and the partial sleeve 71 are integrally formed. The performance of the assembled telescopic shaft is improved.

  Moreover, in Example 1, since the adjacent partial sleeves 71 are independent from each other, high dimensional accuracy is not required. Further, since the shape is simple, the partial sleeves 71 are not entangled with each other when being transported, so that handling becomes easy. Furthermore, even if there is a thermal deformation due to a temperature change, the sliding performance is not easily adversely affected.

  Next, a second embodiment of the present invention will be described. FIGS. 12A and 12B show a state in which the leaf spring is assembled to the partial sleeve according to the second embodiment of the present invention, in which FIG. 12A is a plan view and FIG. 12B is a GG sectional view of FIG. FIG. 13 is a cross-sectional view taken along the line H-H in FIG. 12 (2), and FIG. FIG. 15 is an explanatory view showing a procedure for assembling a leaf spring to the partial sleeve according to the second embodiment of the present invention. In the following description, only structural portions and operations different from the above embodiment will be described, and redundant description will be omitted. Further, the same parts as those in the above embodiment will be described with the same numbers.

  The second embodiment is a modification of the first embodiment, and an engagement portion that engages with the leaf spring 84 and makes the leaf spring 84 axially incapable of relative movement with respect to the partial sleeve 71. This is an example of a different shape.

  In the second embodiment, as in the first embodiment, two through holes 72 and 73, a rectangular groove 713 on the inner periphery 7141 of the connecting sleeve portion 714, and a rectangular groove 715 on the outer periphery 7142 of the connecting sleeve portion 714 are formed. . On the groove bottom surface 7151 of the rectangular groove 715, a cylindrical engagement protrusion 716 is formed at the center in the axial direction. The engagement protrusion 716 protrudes radially outward from the groove bottom surface 7151 integrally with the connection sleeve portion 714, but is set to a height that does not protrude from the outer periphery 7142 of the connection sleeve portion 714. That is, the engagement protrusion 716 constitutes an engagement portion that makes the leaf spring 84 relatively unmovable relative to the partial sleeve 71 in the axial direction.

  As in the first embodiment, the leaf spring 84 has an arcuate shape as a whole, is formed symmetrically from the axial center to the end face in the axial direction, and in order from the axial center, the flat portion 841 and the circle. Arc-shaped portions 844 and 844 are formed. The plate spring 84 of the second embodiment does not have the step portions 842 and 842 and the flat portions 843 and 843 of the first embodiment, and a circular engagement hole 845 is formed instead of the step portions 842 and 842.

  That is, the leaf spring 84 has a linear flat portion 841 at the central portion in the axial direction, and a circular engagement hole 845 is formed at the central portion in the axial direction of the flat portion 841. The diameter of the engagement hole 845 is slightly larger than the diameter of the engagement protrusion 716. As shown in FIG. 12, the arcuate portion 844 is engaged with the engaging hole 845 engaged (externally fitted) with the engaging protrusion 716 of the rectangular groove 715 and the flat portion 841 placed on the groove bottom surface 7151 of the rectangular groove 715. 844 extend through the through holes 72 and 73 to the axial end face side along the rectangular groove 713 while contacting the side surfaces 722 and 732 of the through holes 72 and 73 on the axial end face side.

  The arc-shaped portions 844 and 844 are arc-shaped convex toward the outer side in the radial direction, and are curved in a direction closer to the inner side in the radial direction toward the end face side in the axial direction.

  In order to couple the leaf spring 84 to the partial sleeve 71, as shown in FIG. 15 (1), an end portion 8441 of one arcuate portion 844 of the leaf spring 84 is connected to a connecting sleeve as shown by a white arrow. The portion 714 is inserted into one through hole 72 from the inner periphery 7141. When the leaf spring 84 is further pushed in and the end 8441 of one arcuate part 844 is pushed downward, the arcuate part 844 is curved in a direction closer to the radially inner side toward the end face side in the axial direction. The end portion 8441 of the arc-shaped portion 844 is smoothly inserted into the other through hole 73.

  When the leaf spring 84 is further pushed in, the end portion 8441 of the arc-shaped portion 844 moves along the groove bottom surface 7131 of the rectangular groove 713 toward the end surface side in the axial direction, as shown in FIG. As shown in FIG. 12 (2), when the flat portion 841 is pushed downward and the engaging hole 845 of the flat portion 841 engages with the engaging protrusion 716, the flat portion 841 is placed on the groove bottom surface 7151 of the rectangular groove 715, Since the leaf spring 84 is engaged with the partial sleeve 71 so as not to move in the axial direction, the partial sleeve 71 and the leaf spring 84 are coupled.

  When the partial sleeve 71 and the leaf spring 84 are coupled, the flat portion 841 and the arc-shaped portions 844 and 844 of the leaf spring 84 are partially exposed to the outer periphery 7142 of the connecting sleeve portion 714. The presence or absence of this can be confirmed by the appearance, and it becomes easy to prevent the assembly of the leaf spring 84 from being forgotten.

  The flat portion 841 of the leaf spring 84, a part of the arc-shaped portions 844 and 844, and the engaging protrusion 716 of the connecting sleeve portion 714 are exposed on the outer periphery 7142 of the connecting sleeve portion 714. However, the flat portion 841, a part of the arc-shaped portions 844 and 844, and the engaging protrusion 716 are set to a height that does not protrude from the outer periphery 7142 of the connecting sleeve portion 714.

  Accordingly, the flat portion 841 of the leaf spring 84, a part of the arc-shaped portions 844, 844, and the engaging projection 716 do not contact the bottom surface 412 of the axial groove 41 of the female shaft 12A, and the female shaft 12A is male shaft 12B. It does not get in the way when sliding in the axial direction.

  Next, a third embodiment of the present invention will be described. FIG. 16 shows a state in which a leaf spring is assembled to the partial sleeve according to the third embodiment of the present invention, where (1) is a plan view and (2) is a KK sectional view of (1). FIG. 17 is a cross-sectional view taken along line LL in FIG. 16 (2), and FIG. FIG. 19 is an explanatory diagram showing a procedure for assembling a leaf spring to the partial sleeve according to the third embodiment of the present invention. FIG. 20 is an explanatory view showing another procedure for assembling a leaf spring to the partial sleeve according to the third embodiment of the present invention. In the following description, only structural portions and operations different from the above embodiment will be described, and redundant description will be omitted. Further, the same parts as those in the above embodiment will be described with the same numbers.

  The third embodiment is a modification of the first embodiment, and an engagement portion that engages with the leaf spring 84 and makes the leaf spring 84 axially incapable of relative movement with respect to the partial sleeve 71. This is an example of a different shape.

  In the third embodiment, as in the first embodiment, two through holes 72 and 73, a rectangular groove 713 on the inner periphery 7141 of the connecting sleeve portion 714, and a rectangular groove 715 on the outer periphery 7142 of the connecting sleeve portion 714 are formed. . The through holes 72 and 73 have a rectangular shape, and the left and right groove widths W2 of the through holes 72 and 73 are larger than the left and right widths W3 of the arcuate portion 844 of a leaf spring (see FIGS. 16 and 18) 84 as an urging member. Is also formed slightly larger.

  The left and right groove widths W <b> 1 of the rectangular grooves 713 are slightly larger than the left and right widths W <b> 3 of the arcuate portion 844 of the leaf spring 84. The groove depth δ1 (see FIG. 16B) of the rectangular groove 713 is slightly larger than the plate thickness T1 of the leaf spring 84 (see FIG. 18).

  A rectangular groove 715 is formed on the outer periphery 7142 of the connecting sleeve portion 714 between the central side surface 721 of the through hole 72 and the central side surface 731 of the through hole 73. The left and right groove widths W4 of the rectangular grooves 715 are formed to be the same as the left and right groove widths W1 of the rectangular grooves 713.

  The leaf spring 84 has an arcuate shape as in the first embodiment, is formed symmetrically from the axial center to the end face in the axial direction, and has a flat portion 841 and an arc shape sequentially from the axial center. Portions 844 and 844 are formed.

  The leaf spring 84 of the second embodiment does not have the step portions 842 and 842 and the flat portions 843 and 843 of the first embodiment, and the flat portion 841 forms a wide portion instead of the step portions 842 and 842. That is, the left and right width W5 of the flat portion 841 of the leaf spring 84 is slightly larger than the left and right width W3 of the arcuate portion 844 of the leaf spring 84 and the left and right groove widths W2 of the through holes 72 and 73. Yes.

  As shown in FIG. 16, the arc-shaped portions 844 and 844 are in contact with the side surfaces 722 and 732 on both end sides in the axial direction of the through holes 72 and 73 with the flat portion 841 placed on the groove bottom surface 7151 of the rectangular groove 715. However, it passes through the through holes 72 and 73 and extends along the rectangular groove 713 toward the end face in the axial direction.

  In this state, the side surfaces 86, 86 on both ends in the axial direction of the flat portion 841 of the leaf spring 84 engage with the step portions 723, 733 between the both ends in the axial direction of the rectangular groove 715 and the through holes 72, 73, The leaf spring 84 is set so as not to move in the axial direction with respect to the partial sleeve 71.

  The arc-shaped portions 844 and 844 are arc-shaped convex toward the outer side in the radial direction, and are curved in a direction closer to the inner side in the radial direction toward the end face side in the axial direction.

  In order to couple the leaf spring 84 to the partial sleeve 71, as shown in FIG. 19 (1), the arcuate portions 844, 844 are moved so that the end portions 8441, 8441 of the arcuate portions 844, 844 approach each other around the flat portion 841. The end portions 8441 and 8441 are inserted into both of the through holes 72 and 73 from the outer periphery 7142 side of the connecting sleeve portion 714 by bending in a U shape.

  When the force of bending the arc-shaped portions 844 and 844 is released and the leaf spring 84 is further pushed in, both arc-shaped portions 844 and 844 are moved in the axial direction of the through holes 72 and 73 as shown in FIG. The gaps between the end portions 8441 and 8441 of the arc-shaped portions 844 and 844 are increased by being pushed into both the through holes 72 and 73 along the side surfaces 722 and 732 on both end sides, and the urging force of the leaf spring 84.

  As shown in FIG. 16, when the flat portion 841 is placed on the groove bottom surface 7151 of the rectangular groove 715, the flatness of the leaf spring 84 is maintained even if a force that shifts the leaf spring 84 in the axial direction acts on the partial sleeve 71. Side surfaces 86, 86 on both ends in the axial direction of the portion 841 abut against stepped portions 723, 733 between the both ends in the axial direction of the rectangular groove 715 and the through holes 72, 73, so that the leaf spring 84 is against the partial sleeve 71. Does not move in the axial direction.

  When the partial sleeve 71 and the leaf spring 84 are coupled, the flat portion 841 and the arc-shaped portions 844 and 844 of the leaf spring 84 are partially exposed to the outer periphery 7142 of the connecting sleeve portion 714. The presence or absence of this can be confirmed by the appearance, and it becomes easy to prevent the assembly of the leaf spring 84 from being forgotten.

  Part of the flat portion 841 and the arc-shaped portions 844 and 844 of the leaf spring 84 is exposed on the outer periphery 7142 of the connecting sleeve portion 714. However, a part of the flat portion 841 and the arc-shaped portions 844 and 844 are formed at a height that does not protrude from the outer periphery 7142 of the connecting sleeve portion 714. Accordingly, a part of the flat portion 841 and the arc-shaped portions 844, 844 of the leaf spring 84 does not contact the bottom surface 412 of the axial groove 41 of the female shaft 12A, and the female shaft 12A is axially oriented with respect to the male shaft 12B. It will not get in the way when sliding.

  FIG. 20 is an explanatory view showing another procedure for assembling a leaf spring to the partial sleeve according to the third embodiment of the present invention. That is, as shown in FIG. 16 (1), the groove width W 6 in the diagonal direction of the through holes 72 and 73 is formed larger than the left and right width W 5 of the flat portion 841 of the leaf spring 84.

  Therefore, as shown in FIG. 20, the left and right width W5 of the flat portion 841 of the leaf spring 84 is made substantially parallel to the diagonal groove width W6 of the through holes 72 and 73. Subsequently, the end 8441 of one arcuate portion 844 of the leaf spring 84 is inserted into the one through hole 72 from the inner periphery 7141 of the connecting sleeve portion 714. Then, the flat portion 841 of the leaf spring 84 having the left and right groove width W5 wider than the left and right groove widths W2 of the through holes 72 and 73 can be passed through the through hole 72 to the outer periphery 7142 side of the connecting sleeve portion 714.

  Next, after the leaf spring 84 is made parallel to the groove bottom surface 7151 of the rectangular groove 715 of the flat portion 841, the end portion 8441 of one arcuate portion 844 is bent downward about the flat portion 841 to connect the connecting sleeve. One end 8441 is inserted into the other through-hole 73 from the outer periphery 7142 side of the portion 714.

  When the force to bend the arc-shaped portion 844 is released and the leaf spring 84 is further pushed in, one arc-shaped portion 844 is pushed into the other through-hole 73 along the side surfaces 732 on both end sides in the axial direction of the through-hole 73. Due to the urging force of the leaf spring 84, the end portion 8441 of one arcuate portion 844 is elastically restored.

  As shown in FIG. 16, when the flat portion 841 is placed on the groove bottom surface 7151 of the rectangular groove 715, the side surfaces 86, 86 on both axial sides of the flat portion 841 of the leaf spring 84 are both ends in the axial direction of the rectangular groove 715. Since the plate spring 84 is prevented from moving in the axial direction with respect to the partial sleeve 71, the partial sleeve 71 and the plate spring 84 are coupled. The

  Next, a fourth embodiment of the present invention will be described. FIG. 21 shows a telescopic shaft according to a fourth embodiment of the present invention, and is a perspective view showing a state before the partial sleeve 71 of the fourth embodiment is attached to the male shaft and the female shaft is externally fitted. FIG. 22 is a longitudinal sectional view showing a state where the partial sleeve according to the fourth embodiment of the present invention is assembled to the male shaft. FIG. 23 is a perspective view showing a single plate spring according to a fourth embodiment of the present invention. In the following description, only structural portions and operations different from the above embodiment will be described, and redundant description will be omitted. Further, the same parts as those in the above embodiment will be described with the same numbers.

  The fourth embodiment is a modification of the first embodiment, and an engagement portion that engages with the leaf spring 84 and makes the leaf spring 84 non-movable relative to the partial sleeve 71 in the axial direction is provided on the male shaft. This is an example of formation.

  Since the partial sleeve 71 of the fourth embodiment has substantially the same shape as that of the first embodiment, detailed description thereof will be omitted. However, as shown in FIG. A rectangular groove 713 on the inner periphery 7141 of the sleeve portion 714 and a rectangular groove 715 on the outer periphery 7142 of the connecting sleeve portion 714 are formed.

  As shown in FIG. 22 and FIG. 23, the leaf spring 84 of the fourth embodiment has an arcuate shape as in the first embodiment, and is formed symmetrically from the central portion in the axial direction toward the end face side in the axial direction. A flat portion 841 and arc-shaped portions 844 and 844 are formed in order from the central portion in the axial direction. The leaf spring 84 of the fourth embodiment does not have the step portions 842 and 842 and the flat portions 843 and 843 of the first embodiment, and has the effect of being the simplest in the above-described embodiments.

  Since the method of coupling the leaf spring 84 of the fourth embodiment to the partial sleeve 71 is exactly the same as that of the first embodiment, detailed description thereof is omitted. When the partial sleeve 71 and the leaf spring 84 of the fourth embodiment are coupled, the flat portion 841 of the leaf spring 84 is exposed on the outer periphery 7142 of the connecting sleeve portion 714, so the presence or absence of the assembled leaf spring 84 is confirmed by appearance. This is possible, and it becomes easy to prevent forgetting to assemble the leaf spring 84.

  Accordingly, as shown in FIGS. 21 and 22, when the partial sleeve 71 coupled with the leaf spring 84 is fitted on the outer periphery of the male shaft 12B, the connecting portion between the connecting sleeve portion 714 and the inclined sleeve portion 712 is formed thin. Therefore, the partial sleeve 71 is easily elastically deformed at the connecting portion, and the sleeve 71 can be easily fitted on the outer periphery of the male shaft 12B.

  Therefore, the leaf spring 84 is inserted between the top surface 512 of the outer periphery of the male shaft 12B and the groove bottom surface 7131 of the connecting sleeve portion 714, and the partial sleeve 71 faces outward in the radial direction (radial direction). Energize.

  FIG. 21 shows a state in which one partial sleeve 71 to which the leaf spring 84 is coupled is externally fitted to the outer periphery of the male shaft 12B. The remaining two partial sleeves 71 are also externally fitted to the outer periphery of the male shaft 12B. .

  As shown in FIGS. 21 and 22, the top surface 512 of the outer periphery of the male shaft 12B and the both end portions in the axial direction of the partial sleeve 71 protrude outward in the radial direction, and projecting portions (locking portions). Part) 515 is formed by caulking.

  Accordingly, the convex portions 515 are in contact with both end portions in the axial direction of the three partial sleeves 71 to fix the three partial sleeves 71 so as not to move relative to the male shaft 12B in the axial direction. Further, the convex portion 515 comes into contact with the axial ends 8441 and 8441 of the leaf spring 84, and the leaf spring 84 is locked so as not to move relative to the male shaft 12B in the axial direction. That is, the convex portion 515 constitutes an engaging portion that makes the leaf spring 84 relatively unmovable relative to the partial sleeve 71 in the axial direction.

  In the above embodiment, the axial groove 41 is formed on the female shaft 12A side and the axial ridge 51 is formed on the male shaft 12B side. However, the axial ridge is formed on the female shaft 12A side, and the male shaft An axial groove may be formed on the 12B side.

  In the above embodiment, three axial grooves 41 and three axial ridges 51 are formed at equal intervals. Furthermore, in the above-described embodiment, the example in which the present invention is applied to the steering shaft 12 has been described. However, the present invention can be applied to an arbitrary telescopic shaft constituting the steering device such as the intermediate shaft 16.

  Further, in the above embodiment, the shape of the outer peripheral surface of the female shaft 12A having the axial groove may be circular, rectangular or polygonal, and does not need to be similar to the axial groove of the female shaft 12A.

  Further, in the above embodiment, the convex portion 515 is formed on the inner peripheral surface of the female shaft 12A and on both end portions in the axial direction of the partial sleeve 71 so as to protrude radially inward, and the partial sleeve 71 and the leaf spring 84 are formed. You may fix so that it may not move relatively to the axial direction with respect to the female shaft 12A.

BRIEF DESCRIPTION OF THE DRAWINGS It is the side view which cut off one part and showed the whole steering apparatus of Example 1 of this invention, Comprising: The Example applied to the electric power steering apparatus which has a steering assistance part is shown. It is a longitudinal cross-sectional view of the principal part of FIG. It is a perspective view which shows the expansion-contraction axis | shaft of Example 1 of this invention, attaches the partial sleeve of Example 1 to a male shaft, and shows the state before fitting a female shaft externally. FIG. 3 is an AA enlarged cross-sectional view of FIG. 2, showing a state in which the partial sleeve of Example 1 is attached to the male shaft, and the female shaft is fitted on the outer periphery of the partial sleeve. The partial sleeve single-piece | unit of Example 1 of this invention is shown, (1) is a top view of a partial sleeve, (2) is BB sectional drawing of (1). (1) is a view taken along the arrow P in FIG. 5 (2), (2) is a view taken along the arrow Q in FIG. 5 (2), (3) is a cross-sectional view taken along the line CC in FIG. It is DD sectional drawing of FIG. 5 (2). It is a perspective view which shows the leaf | plate spring single-piece | unit of Example 1 of this invention. The state which attached the leaf | plate spring to the partial sleeve of Example 1 of this invention is shown, (1) is a top view, (2) is EE sectional drawing of (1), (3) is R arrow of (2) FIG. 4 is a cross-sectional view taken along line FF in (2). (1) is an R arrow view of FIG. 8 (2), and (2) is an FF cross-sectional view of FIG. 8 (2). It is explanatory drawing which shows the procedure which attaches a leaf | plate spring to the partial sleeve of Example 1 of this invention. It is a longitudinal cross-sectional view which shows the state which assembled | attached the partial sleeve of Example 1 of this invention to the male shaft. The state which assembled | attached the leaf | plate spring to the partial sleeve of Example 2 of this invention is shown, (1) is a top view, (2) is GG sectional drawing of (1). It is HH sectional drawing of Drawing 12 (2). It is a perspective view which shows the leaf | plate spring single-piece | unit of Example 2 of this invention. It is explanatory drawing which shows the procedure of attaching a leaf | plate spring to the partial sleeve of Example 2 of this invention. The state which attached | attached the leaf | plate spring to the partial sleeve of Example 3 of this invention is shown, (1) is a top view, (2) is KK sectional drawing of (1). It is LL sectional drawing of FIG. 16 (2). It is a perspective view which shows the leaf | plate spring single-piece | unit of Example 3 of this invention. It is explanatory drawing which shows the procedure of attaching a leaf | plate spring to the partial sleeve of Example 3 of this invention. It is explanatory drawing which shows another procedure which attaches a leaf | plate spring to the partial sleeve of Example 3 of this invention. It is a perspective view which shows the expansion-contraction shaft of Example 4 of this invention, attaches the partial sleeve 71 of Example 4 to a male shaft, and shows the state before fitting a female shaft externally. It is a longitudinal cross-sectional view which shows the state which attached the partial sleeve of Example 4 of this invention to the male shaft. It is a perspective view which shows the leaf | plate spring single-piece | unit of Example 4 of this invention.

Explanation of symbols

11 Steering wheel 12 Steering shaft 12A Outer shaft (female shaft)
12B Inner shaft (male shaft)
121B Large-diameter shaft portion 122B Small-diameter shaft portion 13 Steering column 13A Outer column 13B Inner column 14 Support bracket 15 Universal joint 16 Intermediate shaft 16A Male intermediate shaft 16B Female intermediate shaft 17 Universal joint 18 Car body 19 Axis 193 Center line 20 Assist device 21 Gear housing 22 Input shaft 221 Inner diameter hole 23 Output shaft 24 Torsion bar 25 Worm wheel 26 Electric motor 261 Case 27 Worm 28 Torque sensor 29A, 29B, 29C Bearing 30 Steering gear 31 Input shaft 32 Tie rod 41 Axial groove 411 Side surface 412 Bottom surface 414 Connection surface 51 Axial ridge 511 Side surface 512 Top surface 514 Connection surface 515 Convex portion 62 Inclination gap 64 Outer arcuate clearance 71 Partial sleeve 712 Inclination three Portion 7122 outer periphery 7123 grease reservoir 713 rectangular groove 7131 groove bottom surface 714 connecting sleeve portion 7141 inner periphery 7142 outer periphery 715 rectangular groove 7151 groove bottom surface 716 engaging protrusion 72, 73 through hole 721, 731 central side surface 722, 732 both end sides (end surface) Side) 723, 733 Stepped portion 84 Leaf spring 841 Flat portion 842 Stepped portion 843 Flat portion 844 Arc-shaped portion 8441 End portion 845 Engagement hole 86 Side surfaces on both ends

Claims (10)

A male shaft having a non-circular outer peripheral shape,
A female shaft having a non-circular inner peripheral shape that is fitted on the outer periphery of the male shaft so as to be capable of relative movement in the axial direction and to transmit rotational torque;
A plurality of inclined gaps formed in a gap between the non-circular outer periphery and the non-circular inner periphery, and the intervals change at a predetermined inclination;
An elastically deformable inclined sleeve portion that is inserted into the inclined gap and always contacts both the non-circular inner periphery of the female shaft and the non-circular outer periphery of the male shaft; A plurality of partial sleeves arranged in the gap between the non-circular outer periphery,
A pair of through holes formed in the partial sleeve so as to be spaced apart in the axial direction and penetrating from the inner periphery to the outer periphery of the partial sleeve;
The partial sleeve is formed as a separate part, and one end of the partial sleeve is inserted from the outer periphery of the partial sleeve into the inner periphery of the partial sleeve via one of the through holes, and the other end is inserted from the outer periphery of the partial sleeve. It is inserted into the inner periphery of the partial sleeve via the other of the through-holes, its axial center is exposed on the outer periphery of the partial sleeve and joined to the partial sleeve, and both ends of the non-circular outer periphery and the partial sleeve An urging member that is inserted into a gap between the inner circumference and urges the inclined sleeve portion from the maximum gap portion side to the minimum gap portion side of the inclined gap to apply a preload to the partial sleeve; Telescopic shaft characterized by that. The telescopic shaft according to claim 1,
The partial sleeve has a connecting sleeve portion that is inserted into a gap between the non-circular outer periphery and the non-circular inner periphery and connects the radially outer ends of the adjacent inclined sleeve portions;
The telescopic shaft, wherein the pair of through holes are formed in the connecting sleeve portion. In the telescopic shaft according to claim 2,
A telescopic shaft, wherein an engaging portion formed on the connecting sleeve portion engages with the urging member to make the urging member immovable relative to the partial sleeve in the axial direction. In the telescopic shaft according to claim 3,
The engaging portion is
A telescopic shaft, characterized in that the telescopic shaft is a side surface on both end sides in the axial direction of the through hole that engages with radial step portions formed on both end sides in the axial direction of the biasing member. In the telescopic shaft according to claim 3,
The engaging portion is
A telescopic shaft, wherein the telescopic shaft is an engaging protrusion that engages with an engaging hole formed in the biasing member. In the telescopic shaft according to claim 3,
The engaging portion is
A stepped portion on the center side of the through hole that engages with side surfaces of both ends in the axial direction of the wide portion formed at a substantially central portion in the axial direction of the biasing member and has a groove width narrower than the wide portion. Telescopic shaft characterized by being. The telescopic shaft according to claim 1,
The male shaft is in contact with both ends in the axial direction of the partial sleeve, is relatively movable in a direction perpendicular to the axial direction of the male shaft, and is not relatively movable in the axial direction of the male shaft. A locking part for locking the partial sleeve to the male shaft is formed,
A telescopic shaft, wherein both ends of the urging member in the axial direction abut against the locking portion, and the urging member is locked so as not to be relatively movable in the axial direction. In the telescopic shaft according to any one of claims 1 to 7,
A flat portion substantially parallel to the axial direction is formed at a substantially central portion in the axial direction of the urging member,
A telescopic shaft, characterized in that arc-shaped portions that are curved toward the radially inner side are formed at both ends of the urging member toward the both ends in the axial direction. In the telescopic shaft according to claim 8,
A telescopic shaft, wherein the biasing member is a leaf spring.   A steering apparatus having the telescopic shaft according to any one of claims 1 to 9.

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