JP2006177517A - Telescopic shaft for vehicle steering - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To significantly reduce sliding force while preventing rattling between shafts in sliding and to transmit torque in a high rigidity state in transmitting torque. <P>SOLUTION: It is important to improve lubricity between a cylindrical body 8 and both shafts 1, 2 to keep low sliding force in a state that torque is loaded. As a plurality of circumferential grooves 40 are formed on an outer peripheral face of the cylindrical body 8, oil and grease can be stored in the circumferential grooves 40, thus the lubricant hardly run short, and the lubricity can be improved. As the absence of an oil film hardly occurs even in sliding under the state that the torque is loaded, the sliding force can be kept low. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a telescopic shaft for vehicle steering that is incorporated in a steering shaft of a vehicle and has a male shaft and a female shaft that are non-rotatable and slidably fitted to each other.

  The telescopic shaft of the steering mechanism portion of the automobile is required to absorb the axial displacement generated when the automobile travels and to transmit the displacement and vibration on the steering wheel. Further, in order to obtain an optimum position for the driver to drive the automobile, a function of moving the position of the steering wheel in the axial direction and adjusting the position is required.

  In any of these cases, the telescopic shaft is required to reduce the rattling noise, to reduce the rattling on the steering wheel, and to reduce the sliding resistance during the sliding operation in the axial direction. The

  Therefore, conventionally, the male shaft of the telescopic shaft is coated with a resin film, and grease is applied to the sliding portion to absorb or reduce metal noise, metal hitting sound, etc., and to reduce sliding resistance. The rotation direction play has been reduced.

  However, the wear of the resin film may progress with the course of use, and the rotational play may increase. In addition, under conditions where the engine room is exposed to high temperatures, the volume of the resin film changes, and the sliding resistance increases remarkably or wear significantly increases, which may increase the backlash in the rotational direction. .

  For this reason, in Patent Document 1, a plurality of sets of sliding bodies are fitted between a plurality of sets of axial grooves formed on the outer peripheral surface of the male shaft and the inner peripheral surface of the female shaft, Between a plurality of sets of axial grooves formed on the outer peripheral surface of the male shaft and the inner peripheral surface of the female shaft, rolling elements that roll in the axial relative movement of both shafts are fitted.

  A preload leaf spring for applying preload to the male shaft and the female shaft is provided between the rolling element and the axial groove through the rolling element.

This prevents backlash between the male shaft and the female shaft during sliding, and the male shaft and the female shaft can slide in the axial direction with a stable sliding load without backlash. . Further, at the time of torque transmission, the male shaft and the female shaft can prevent backlash in the rotational direction and transmit torque in a highly rigid state.
JP 2003-336658 A

  However, sliding force at various temperatures (−40 to 140 ° C.) between the resin-coated stretchable shaft coated with the resin and the mechanical stretchable shaft interposed between the cylindrical body and the spherical body was measured while applying a torque. .

  As a result, the sliding force between the resin-coated telescopic shaft and the mechanical telescopic shaft was lower on the resin-coated telescopic shaft than on the mechanical telescopic shaft at each temperature.

  The present invention has been made in view of the above-described circumstances, and at the time of sliding, while preventing backlash between both shafts, the sliding force can be significantly reduced. An object is to provide a telescopic shaft for vehicle steering that can transmit torque in a rigid state.

In order to achieve the above object, a telescopic shaft for vehicle steering according to claim 1 of the present invention is incorporated in a steering shaft of a vehicle, and is for vehicle steering in which a male shaft and a female shaft are fitted non-rotatably and slidably. In the telescopic axis,
Between at least one row of axial grooves formed on the outer peripheral surface of the male shaft and the inner peripheral surface of the female shaft, a sliding body that slides and slides in the axial relative movement of both wheels is interposed. Yes,
At least one groove is formed on the outer peripheral surface of the sliding body.

  Further, the telescopic shaft for vehicle steering according to claim 2 of the present invention has an elastic body interposed between at least one row of axial grooves formed on the outer peripheral surface of the male shaft and the inner peripheral surface of the female shaft. In addition, a rolling element that rolls when the two shafts move in the axial direction is interposed.

  In order to keep the sliding force low while torque is applied, it is important to improve the lubricity between the sliding body and both shafts. The reason for this is that the resin-coated telescopic shaft is superior for simple sliding.

  According to the present invention, since at least one groove is formed on the outer peripheral surface of the sliding body, oil or grease can be stored in the groove, so that the lubricant is hardly interrupted and the lubricity is improved. Can do. Therefore, even when sliding with a torque applied, the oil film is not cut, so that the sliding force can be kept low.

  Therefore, the sliding force can be remarkably reduced while preventing backlash between the two shafts during sliding, while the torque can be transmitted in a highly rigid state during torque transmission.

  Hereinafter, a telescopic shaft for vehicle steering according to an embodiment of the present invention will be described with reference to the drawings.

(Overall configuration of vehicle steering shaft)
FIG. 1 is a side view of a steering mechanism portion of an automobile to which a vehicle steering telescopic shaft according to an embodiment of the present invention is applied.

  In FIG. 1, an upper steering shaft portion 120 (a steering column 103 and a swinging shaft 104 rotatably supported by the steering column 103 are attached to a member 100 on the vehicle body side via an upper bracket 101 and a lower bracket 102. A steering wheel 105 attached to the upper end of the steering shaft 104, a lower steering shaft portion 107 connected to the lower end of the steering shaft 104 via a universal joint 106, and a steering shaft joint 108 to the lower steering shaft portion 107. A pinion shaft 109 connected via a pin, a steering rack shaft 112 connected to the pinion shaft 109, and the steering rack shaft 112 is supported to elastically move to another frame 110 of the vehicle body. Steering mechanism from a fixed steering rack support member 113 via 111 is formed.

  Here, the upper steering shaft portion 120 and the lower steering shaft portion 107 use the vehicle steering telescopic shaft (hereinafter referred to as the telescopic shaft) according to the embodiment of the present invention. The lower steering shaft portion 107 is formed by fitting a male shaft and a female shaft. The lower steering shaft portion 107 absorbs axial displacement generated when the automobile travels, and the steering wheel. The performance which does not transmit the displacement and vibration on 105 is required. In such performance, the vehicle body has a sub-frame structure, and the member 100 for fixing the upper part of the steering mechanism and the frame 110 to which the steering rack supporting member 113 is fixed are separated, and the steering rack supporting member 113 is This is required in the case of a structure that is fastened and fixed to the frame 110 via an elastic body 111 such as rubber. In other cases, when the steering shaft joint 108 is fastened to the pinion shaft 109, an operator may need to have a telescopic function so that the telescopic shaft is once contracted and then fitted to the pinion shaft 109 and fastened. . Further, the upper steering shaft portion 120 at the upper part of the steering mechanism also has a male shaft and a female shaft fitted to each other. The upper steering shaft portion 120 is used for a driver to drive a car. In order to obtain an optimal position, the function of moving the position of the steering wheel 105 in the axial direction and adjusting the position is required, and thus a function of expanding and contracting in the axial direction is required. In all the cases described above, it is possible to reduce the rattling noise of the fitting portion on the telescopic shaft, to reduce the backlash on the steering wheel 105, and to reduce the sliding resistance when sliding in the axial direction. Required.

(First embodiment)
FIG. 2A is a longitudinal sectional view of the telescopic shaft for vehicle steering according to the first embodiment of the present invention, and FIG. 2B is a perspective view of a leaf spring that is an elastic body.

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

  As shown in FIG. 2, the telescopic shaft for vehicle steering includes a male shaft 1 and a female shaft 2 that are non-rotatable and slidably fitted to each other.

  As shown in FIG. 3, three axial grooves 3 that are equally arranged at intervals of 120 degrees (phase) in the circumferential direction are formed to extend on the outer circumferential surface of the male shaft 1. Correspondingly, three axial grooves 5 that are equally arranged at intervals of 120 degrees (phase) in the circumferential direction are formed to extend on the inner peripheral surface of the female shaft 2.

  Between the axial groove 3 of the male shaft 1 and the axial groove 5 of the female shaft 2, a plurality of rigid spherical bodies 7 (rolling bodies, which roll when the two shafts 1 and 2 move in the axial direction relative to each other). Ball) is installed to roll freely. The axial groove 5 of the female shaft 2 has a substantially arc-shaped cross section or a Gothic arch shape.

  The axial groove 3 of the male shaft 1 is composed of a pair of inclined planar side surfaces 3a and a bottom surface 3b formed flat between the pair of planar side surfaces 3a.

  A leaf spring 9 (elastic body) for contacting and preloading the spherical body 7 is interposed between the axial groove 3 of the male shaft 1 and the spherical body 7.

  The leaf spring 9 has a substantially arc-shaped spherical body-side contact portion 9a that contacts the spherical body 7 at two points, and is bent at a predetermined interval in the circumferential direction with respect to the spherical body-side contact portion 9a. The groove surface side contact portion 9b that can come into contact with the planar side surface 3a of the axial groove 3 of the male shaft 1, and the spherical body side contact portion 9a and the groove surface side contact portion 9b are elastically biased in a direction away from each other. And an urging portion 9c bent so as to have a flat bottom surface 9d facing the flat bottom surface 3b of the axial groove 3.

  The urging portion 9c has a substantially U shape and is bent in a substantially arc shape, and the spherical body side contact portion 9a and the groove surface side contact portion 9b are mutually connected by the bent urging portion 9c. Can be elastically biased so as to be separated from each other.

  As shown in FIG. 3, three axial grooves 4 that are equally arranged at intervals of 120 degrees (phase) in the circumferential direction are formed to extend on the outer circumferential surface of the male shaft 1. Correspondingly, three axial grooves 6 that are equally arranged at intervals of 120 degrees (phase) in the circumferential direction are formed to extend on the inner peripheral surface of the female shaft 2.

  A plurality of rigid cylindrical bodies 8 (sliding bodies) that slide between the axial grooves 4 of the male shaft 1 and the axial grooves 6 of the female shaft 2 when the two shafts 1 and 2 move relative to each other in the axial direction. , A needle roller) is interposed with a minute gap. The axial grooves 4 and 6 have a substantially circular arc shape or a Gothic arch shape in cross section.

  In the present embodiment, a stopper plate 10 that restricts the movement of the cylindrical body 8 in the axial direction is provided at the end of the male shaft 1.

  Further, a lubricant may be applied between the axial groove 3 of the male shaft 1, the axial groove 5 of the female shaft 2, the leaf spring 9, and the spherical body 7. A lubricant may also be applied between the axial groove 4 of the male shaft 1, the cylindrical body 8, and the axial groove 6 of the female shaft 2.

  In the telescopic shaft configured as described above, the spherical body 7 is interposed between the male shaft 1 and the female shaft 2, and the spherical body 7 is preloaded to the extent that the female shaft 2 is not rattled by the leaf spring 9. Therefore, the play between the male shaft 1 and the female shaft 2 can be reliably prevented, and when the male shaft 1 and the female shaft 2 move relative to each other in the axial direction, there is no stable play. It is possible to slide with the sliding load.

  At the time of torque transmission, the leaf spring 9 is elastically deformed to constrain the spherical body 7 in the circumferential direction, and the three rows of cylindrical bodies 8 interposed between the male shaft 1 and the female shaft 2 play a main role in torque transmission. Fulfill.

  For example, when torque is input from the male shaft 1, since the preload of the leaf spring 9 is applied in the initial stage, there is no backlash, and the leaf spring 9 generates a reaction force against the torque and transmits the torque. . At this time, overall torque transmission is performed in a state where the transmission torque and the input torque between the male shaft 1, the leaf spring 9, the spherical body 7, and the female shaft 2 are balanced.

  As the torque further increases, the clearance in the rotational direction of the male shaft 1 and female shaft 2 via the cylindrical body 8 disappears, and the subsequent torque increase is transmitted via the male shaft 1 and female shaft 2 to the cylindrical body. 8 communicates. Therefore, it is possible to reliably prevent backlash in the rotational direction of the male shaft 1 and the female shaft 2 and to transmit torque in a highly rigid state.

  As described above, according to the present embodiment, since the cylindrical body 8 is provided in addition to the spherical body 7, most of the load can be supported by the cylindrical body 8 when a large torque is input. Therefore, the contact pressure between the axial groove 5 of the female shaft 2 and the spherical body 7 can be reduced to improve durability, and torque can be transmitted in a highly rigid state at the time of a large torque load. .

  Thus, according to the present embodiment, it is possible to realize a stable sliding load, reliably prevent backlash in the rotational direction, and transmit torque in a highly rigid state.

  The spherical body 7 is preferably a rigid ball. The rigid cylindrical body 8 is preferably a needle roller.

Since the cylindrical body (hereinafter referred to as a needle roller) 8 receives the load by line contact, it has various effects such as a lower contact pressure than a ball receiving a load by point contact. Therefore, the following items are superior to the case where the entire row has a ball rolling structure.
・ The damping effect at the sliding part is larger than that of the ball rolling structure. Therefore, vibration absorption performance is high.
・ Since the needle roller is in minute contact with the male shaft and the female shaft, the fluctuation range of the sliding load can be kept low, and the vibration due to the fluctuation is not transmitted to the steering.
-If the same torque is transmitted, the needle roller can keep the contact pressure lower, so the axial length can be shortened and the space can be used effectively.
-If the same torque is transmitted, the contact pressure of the needle roller can be kept lower, so that an additional step for curing the axial groove surface of the female shaft by heat treatment or the like is unnecessary.
・ The number of parts can be reduced.
・ Assembly can be improved.
・ Assembly costs can be reduced.

In this way, the needle roller serves as a key for torque transmission between the male shaft 1 and the female shaft 2, and is in sliding contact with the inner peripheral surface of the female shaft 2. The use of the needle roller is superior to the conventional spline fitting as follows.
・ Needle rollers are mass-produced products and are very low cost.
-Since the needle roller is polished after heat treatment, it has high surface hardness and excellent wear resistance.
-Since the needle roller is polished, the surface roughness is fine and the friction coefficient during sliding is low, so the sliding load can be kept low.
-Since the length and arrangement of the needle roller can be changed according to the use conditions, it can be used for various applications without changing the design concept.
・ Depending on the usage conditions, the friction coefficient during sliding may have to be further reduced. At this time, if only the needle roller is surface-treated, its sliding characteristics can be changed, so the design philosophy is not changed. , Can correspond to various applications.
-Since needle rollers with different outer diameters can be manufactured at low cost in units of several microns, the gap between the male shaft, needle roller, and female shaft can be minimized by selecting the needle roller diameter. Therefore, it is easy to improve the torsional rigidity of the shaft.

  In addition, as described above, the leaf spring 9 is separated from the spherical body-side contact portion 9a that contacts the spherical body 7 at two points, and is spaced apart from the spherical body-side contact portion 9a by a predetermined interval in a substantially circumferential direction. The groove surface side contact portion 9b that contacts the planar side surface 3a of the axial groove 3 of the male shaft 1, and the spherical body side contact portion 9a and the groove surface side contact portion 9b are elastically biased in a direction away from each other. The urging portion 9c and the bottom surface 9d facing the bottom surface 3b of the axial groove 3 are paired on the left and right.

  The urging portion 9c has a substantially U shape and is bent in a substantially arc shape, and the spherical body side contact portion 9a and the groove surface side contact portion 9b are mutually connected by the bent urging portion 9c. Can be elastically biased so as to be separated from each other. Therefore, the spherical spring side contact portion 9a of the leaf spring 9 can be sufficiently bent through the biasing portion 9b, and a sufficient amount of bending can be ensured.

  Accordingly, the leaf spring 9 is provided with a space between the spherical body side contact portion 9a that contacts the spherical body 7 and the groove surface side contact portion 9b that contacts the axial groove 3, and the space is elastically connected therebetween. It is. Therefore, the stress generated at the contact portion between the spherical body 7 and the leaf spring 9 can be relieved at the time of setting, and the desired preload performance can be obtained over a long period by preventing the leaf spring 9 from sag due to permanent deformation. it can.

  Further, if the spherical body side contact portion 9a that contacts the spherical body 7 is formed in a substantially arc shape larger than the radius of the spherical body 7, the contact surface pressure with the spherical body 7 can be lowered than the planar shape, Further preferred.

  Further, the leaf spring 9 can secure a sufficient amount of bending, and the spherical body 7 and the leaf spring 9 are not subjected to an excessive load (stress). In addition, the stress generated at the contact point with the leaf spring 9 can be relieved, so that high stress is not generated, “sagging” due to permanent deformation is prevented, and preload performance is maintained over a long period of time. be able to.

  Furthermore, the contact point with the spherical body 7 is strong, and the portion exhibiting the spring property is easily bent so that the race surface and the spring property can be achieved with a single member. Further, in the present embodiment, the cylindrical body 8 mainly transmits torque, so that no excessive stress is generated between the male shaft 1, the female shaft 2, the leaf spring, and the spherical body 7.

  Accordingly, it is necessary to prevent excessive stress from being generated in the leaf spring 9 to prevent the leaf spring 9 from sag, to maintain desired preload performance over a long period of time, and to strictly control the dimensional accuracy. In addition, the leaf spring 9 and the race portion can be formed from a single material, and the manufacturing cost can be reduced by facilitating the assembly.

  In the present embodiment, at least one circumferential groove 40 is formed on the outer peripheral surface of the cylindrical body 8 (sliding body, needle roller), which will be described later.

(Second Embodiment)
FIG. 4 is an exploded perspective view of the telescopic shaft for vehicle steering according to the second embodiment of the present invention.

  5 is a longitudinal sectional view of the vehicle steering telescopic shaft shown in FIG.

  6 is a cross-sectional view taken along line VI-VI in FIG.

  FIG. 7 is a cross-sectional view taken along line VII-VII in FIG.

  Since the basic structure of this embodiment is the same as that of the first embodiment described above, differences will be mainly described.

  As shown in FIG. 4, in this embodiment, a pair of spherical bodies 7 and two sets of columnar bodies 8 are interposed between the male shaft 1 and the female shaft 2.

  As shown in FIGS. 4 and 5, in this embodiment, a pair of spherical bodies with a leaf spring 9 interposed between the axial groove 3 of the male shaft 1 and the axial groove 5 of the female shaft 2. 7, a short cylindrical body 30 (needle roller, sliding body) is slidably interposed.

  As shown in FIG. 7, when no torque is applied to the male shaft 1 or the female shaft 2, the gap between the substantially arc-shaped axial groove 5 of the female shaft 2 and the cylindrical body 30 (needle roller, sliding body). Has a minute gap (ΔR) in the rotational direction.

  In addition, the clearance (ΔR) between the male shaft 1, the cylindrical body 30, and the female shaft 2 is larger than the clearance (ΔB) between the male shaft 1, the leaf spring 9, the spherical body 7, and the female shaft 2. It is set small.

  As shown in FIGS. 4 and 5, two circumferential grooves 20 are formed at both ends of the cylindrical body 8 and the male shaft 1 at which one end of the cylindrical body 30 is located. Thereby, the two retaining rings 21 are fitted into the circumferential groove 20 to fix the two cylindrical bodies 8 in the axial direction.

  Further, as shown in FIG. 6, the leaf spring 9 is locked to the step portions 11 on both sides of the axial groove 3 of the male shaft 1 by the concave portions 12 at both ends thereof. The whole spring 9 cannot be moved in the circumferential direction.

  In this embodiment, when an excessive torque is input, as shown in FIGS. 6 and 7, in the pair of axial grooves 3 and 5 in which the spherical body 7 with the leaf spring 9 interposed is disposed, Further, not only the spherical body 7 but also one short cylindrical body 30 is arranged, and the rotation direction clearance (ΔR) between the male shaft 1, the cylindrical body 30, and the female shaft 2 is the male shaft 1. It is set smaller than the gap (ΔB) between the leaf spring 9, the spherical body 7, and the female shaft 2. Therefore, when an excessive torque is input, the cylindrical body 30 is inserted into the axial grooves 3 and 5 before the gap (ΔB) between the male shaft 1, the leaf spring 9, the spherical body 7, and the female shaft 2 is completely eliminated. Can touch. As a result, most of the excessive torque acts on the cylindrical body 30 and hardly acts on the spherical body 7. Accordingly, the cylindrical body 30 receives an excessive torque load due to the line contact, and the spherical body 7 does not receive an excessive torque load. Therefore, the cylindrical body 30 is locally subjected to the point contact (point pressure contact) of the conventional spherical body 7. There is no increase in surface pressure, adhesion of the indentation of the spherical body 7 can be prevented, and deterioration of sliding performance due to the indentation is not caused. For this reason, at the time of torque transmission, it is possible to reliably prevent backlash in the rotational direction between the male shaft and the female shaft and transmit torque in a highly rigid state.

  In the present embodiment, at least one circumferential groove 40 is formed on the outer peripheral surface of the cylindrical body 8 (sliding body, needle roller) and the outer peripheral surface of the short cylindrical body 30 (needle roller, sliding body). This will be described later.

  FIG. 8 is a longitudinal sectional view of a telescopic shaft for vehicle steering according to a modification of the second embodiment of the present invention.

  In this modification, two short cylindrical bodies 30 are arranged on both sides of the spherical body 7 in the pair of axial grooves 3 and 5, respectively. Thereby, it is possible to provide a structure that can withstand the load input in the falling direction. Other configurations, operations, effects, and the like are the same as those in the above-described embodiment.

(Third embodiment)
FIG. 9 is a side view of a cylindrical body (sliding body, needle roller) according to the third embodiment of the present invention.

  FIG. 10 is a side view of a cylindrical body (sliding body, needle roller) according to a first modification of the third embodiment of the present invention.

  FIG. 11A is a side view of a cylindrical body (sliding body, needle roller) according to a second modification of the third embodiment of the present invention, and FIG. 11B is surrounded by a circle in FIG. It is an enlarged view of the part.

  FIG. 12A is a side view of a cylindrical body (sliding body, needle roller) according to a third modification of the third embodiment of the present invention, and FIG. It is sectional drawing along a line.

  FIG. 13 is a side view of a cylindrical body (sliding body, needle roller) according to a fourth modification of the third embodiment of the present invention.

  In the embodiment of FIG. 9, a plurality of circumferential grooves 40 are formed on the outer peripheral surfaces of the cylindrical bodies 8 and 30 (sliding bodies and needle rollers).

  The number of the circumferential grooves 40 is preferably 3-5, but at least one is sufficient. Moreover, although the cylindrical bodies 8 and 30 are crowned, they may not be formed in particular.

  In the present embodiment, the material of the cylinders 8 and 30 is conventionally SUJ2 (bearing steel, about HR60), but in order to insert the circumferential groove 40, it may be ground steel (including brass and copper). Good. Brass and copper have good compatibility with STKM (pipe material) and SXXC (bar steel) used for the male shaft 1 and the female shaft 2. Moreover, in order to insert the circumferential groove | channel 40, it is good also as an injection molded product by engineering plastics. Furthermore, in order to insert the circumferential groove 40, die casting using a non-ferrous metal as a material may be used. In addition, the material of the cylindrical bodies 8 and 30 is not limited to these.

  In order to keep the sliding force low in a state where torque is applied, it is important to improve the lubricity between the cylinders 8 and 30 and the shafts 1 and 2.

  According to the present embodiment, since a plurality of circumferential grooves 40 are formed on the outer peripheral surfaces of the cylindrical bodies 8 and 30, oil and grease can be stored in the circumferential grooves 40. However, the lubricity can be improved. Therefore, even when sliding with a torque applied, the oil film is not cut, so that the sliding force can be kept low.

  Therefore, the sliding force can be remarkably reduced while preventing backlash between the shafts 1 and 2 during sliding, while the torque can be transmitted in a highly rigid state during torque transmission.

  In the example of FIG. 10, spiral grooves 41 are formed on the outer peripheral surfaces of the cylindrical bodies 8 and 30 (sliding bodies and needle rollers). The number of the spiral grooves 41 is one, but may be multiple. In this case, from the manufacturing aspect, the number of processing steps is small, and the manufacturing cost can be suppressed. Other configurations, operations, and effects are the same as those in the above-described embodiment.

  In the example of FIG. 11, spiral grooves 41 are formed on the outer peripheral surfaces of the cylindrical bodies 8 and 30 (sliding bodies and needle rollers). The spiral groove 41 is embedded with a porous elastic body 42 or is fitted as a separate body. In this case, the oil can be firmly held in the porous elastic body 42, and the lubricant can be reliably held to further improve the lubricity. Other configurations, operations, and effects are the same as those in the above-described embodiment.

  In the example of FIG. 12, a plurality of axial grooves 43 are formed on the outer peripheral surface of the cylindrical bodies 8 and 30 (sliding bodies and needle rollers). The number of the axial grooves 43 is preferably 3 to 5, but may be at least one. In this case, the part which does not form a groove is left and right of the axial groove 43. This is to prevent the axial groove 43 from engaging the edge of the axial groove 4 of the male shaft 1. Other configurations, operations, and effects are the same as those in the above-described embodiment.

  In the example of FIG. 13, a plurality of axial grooves 43 are formed on the outer peripheral surface of the cylindrical bodies 8 and 30 (sliding bodies and needle rollers) and arranged in a staggered manner. In this case, the part which does not form a groove is left on the left and right end sides of the axial groove 43. This is to prevent the axial groove 43 from engaging the edge of the axial groove 4 of the male shaft 1. Other configurations, operations, and effects are the same as those in the above-described embodiment.

  In addition, this invention is not limited to embodiment mentioned above, A various deformation | transformation is possible.

1 is a side view of a steering mechanism portion of an automobile to which a telescopic shaft for vehicle steering according to an embodiment of the present invention is applied. (A) is a longitudinal cross-sectional view of the telescopic shaft for vehicle steering which concerns on 1st Embodiment of this invention, (b) is a perspective view of the leaf | plate spring which is an elastic body. FIG. 3 is a cross-sectional view taken along line III-III in FIG. It is a disassembled perspective view of the telescopic shaft for vehicle steering which concerns on 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the telescopic shaft for vehicle steering shown in FIG. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. It is a cross-sectional view along the VII-VII line of FIG. It is a longitudinal cross-sectional view of the telescopic shaft for vehicle steering which concerns on the modification of 2nd Embodiment of this invention. FIG. 10 is a side view of a cylindrical body (sliding body, needle roller) according to a third embodiment of the present invention. It is a side view of a cylindrical body (sliding body, needle roller) according to a first modification of the third embodiment of the present invention. (A) is related with the 2nd modification of 3rd Embodiment of this invention, and is a side view of a cylindrical body (sliding body, needle roller), (b) is the part enclosed by the circle of (a). FIG. (A) is related with the 3rd modification of 3rd Embodiment of this invention, It is a side view of a cylindrical body (sliding body, needle roller), (b) is bb line of (a). FIG. FIG. 20 is a side view of a cylindrical body (sliding body, needle roller) according to a fourth modification of the third embodiment of the present invention.

Explanation of symbols

1 Male shaft 2 Female shaft 3 Axial groove 3a Planar side surface 3b Bottom surface 4 Axial groove 5 Axial groove 6 Axial groove 7 Spherical body (ball, rolling element)
8 Cylindrical body (needle roller, sliding body)
9 Leaf spring (elastic body)
9a Spherical body side contact part (transmission member side contact part)
9b Groove surface side contact portion 9c Biasing portion 9d Bottom surface 10 Stopper plate 11 Step portion 12 Recess portion 20 Circumferential groove 21 Retaining ring 30 Short cylindrical body (needle roller, sliding body)
40 circumferential groove 41 spiral groove 42 porous elastic body 43 axial groove 100 member 101 upper bracket 102 lower bracket 103 steering column 104 steering shaft 105 steering wheel 106 universal joint 107 lower steering shaft portion 108 steering shaft joint 109 pinion shaft 110 Frame 111 Elastic body 112 Steering rack shaft 113 Steering rack support member 120 Upper steering shaft portion

Claims (2)

In the telescopic shaft for vehicle steering, which is incorporated in the steering shaft of the vehicle and the male shaft and the female shaft are slidably fitted to each other,
Between at least one row of axial grooves formed on the outer peripheral surface of the male shaft and the inner peripheral surface of the female shaft, a sliding body that slides and slides in the axial relative movement of both wheels is interposed. Yes,
A telescopic shaft for vehicle steering, wherein at least one groove is formed on an outer peripheral surface of the sliding body.   A roller that rolls in the axial relative movement of the two shafts via an elastic body between at least one row of axial grooves formed on the outer peripheral surface of the male shaft and the inner peripheral surface of the female shaft. 2. A telescopic shaft for vehicle steering according to claim 1, wherein a moving body is interposed.

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