JPH0556740U - Electric telescopic steering device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent rattling at the meshing part between the splines of the outer shaft and inner shaft. Prevent the inner shaft from tilting. [Structure] An inner shaft 9 having a left-hand thread is passed through a rattling adjustment rod 13 having a right-hand thread 13a at its front end and a left-hand thread engaging with the left-hand thread of the shaft 9 at its rear end. The nut 10 having the serrations 19 formed on the outer peripheral surface is screwed into the right-hand thread 13a. Shaft 9 around rod 13
A sleeve (11) having a serration (20) formed on the outer peripheral surface is fitted between the nut and the nut (10). The rattling prevention members 14 and 15 are fitted around the rod 13 between the shaft 9 and the sleeve 11 and between the sleeve 11 and the nut 10. Shaft 9
Tapered holes 21, 31, 25 are formed at the front end of the sleeve 11, the front and rear ends of the sleeve 11, and the rear end of the nut 10, respectively, and a plurality of slits 22, 32, 27 are formed around them. Push-expanding portions 14a, 14b, 15a, 15b are formed at both front and rear ends of both members 14, 15.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to an electric telescopic steering device used in automobiles and the like.

In this specification, the term spline is used to include all spline style joints such as splines and serrations. Further, in this specification, the left side of FIG. 1 is referred to as the front and the right side of FIG. 1 is referred to as the rear.

[0003]

[Prior Art]

 Conventionally, this type of electric telescopic steering device has a hollow outer shaft with a serration formed on the inner circumference and a hollow outer shaft with serrations that mesh with the serration of the outer shaft and is inserted into the outer shaft. It is known that a steering shaft having a circular inner shaft is provided, and the steering shaft can be expanded and contracted by the rotation of an electric motor.

[0004]

[Problems to be solved by the device]

 However, in the conventional electric telescopic steering device, rattling occurs at the meshing part between the serrations of the outer shaft and the inner shaft, and the inner shaft tilts with respect to the outer shaft, causing rattling of the steering shaft. There was a problem.

An object of the present invention is to provide an electric telescopic steering device that solves the above problems.

[0006]

[Means for Solving the Problems]

 The electric telescopic steering device according to the present invention is a hollow inner shaft having a hollow outer shaft with a spline formed on the inner periphery and a spline that meshes with a spline of the outer shaft on the outer periphery and is inserted into the outer shaft. An electric-type telescopic steering device having a steering shaft having a shaft and a steering shaft extending and contracting by rotation of an electric motor, wherein a screw is formed on a front end portion of an inner shaft. While the rattling adjustment rod is passed through, the front part of the rattling adjusting rod is projected forward from the inner shaft, and the part around the rattling adjusting rod in front of the inner shaft and the outer shaft of the outer shaft are attached to the outer peripheral surface. A spline that meshes with the spline is formed A sleeve is fitted, and a nut with a spline that meshes with the spline of the outer shaft is formed on the outer peripheral surface of the screw at the front end of the rattling adjustment rod.The nut is inserted between the inner shaft and the sleeve and between the sleeve and the nut. Between the rattling adjustment rods, the rattling prevention members are fitted, and the front end of the inner shaft, the front and rear ends of the sleeve, and the rear end of the nut taper toward the other end. Along with the hole being formed, a plurality of slits extending axially from the above end are formed in the peripheral portion of the tapered hole. There is a push expansion part that expands the peripheral part of the inner shaft of the inner shaft, which has a different twist direction from the nut thread. There are formed, on the outer peripheral surface of the backlash adjusting rod, in which a screw meshing with the screw of the inner shaft is formed.

[0007]

[Action]

 When the nut is moved rearward with respect to the rod by rotating the rattling adjustment rod around its axis, a screw formed on the inner peripheral surface of the inner shaft and different from the twist direction of the nut screw , The inner shaft is moved forward with respect to the rattling adjustment rod by the action of the screw formed on the rattling adjusting rod and engaging with the screw so that the nut and the inner shaft come close to each other, The expanded portion of the anti-sticking member contacts the inner peripheral surface of the inner shaft, nut, and taper hole of the sleeve. The inner shaft, the nut, and the sleeve have a plurality of slits that extend in the axial direction around the tapered hole.Therefore, when the rod is further rotated in the same direction, the inner shaft, the nut, and the sleeve have tapered holes. The surrounding parts are pushed radially outward by the expansion parts to open. Therefore, this prevents rattling at the meshing portion between the spline of the outer shaft and the spline of the inner shaft, the nut and the sleeve.

Further, the sleeve and the rattling prevention member are tightened by the rattling adjustment rod, the nut, and the inner shaft, and the inner shaft, the nut, and the sleeve are fixedly integrated. This integrated product is supported by the meshing parts between the splines of the outer shaft and the inner shaft, the meshing parts between the splines of the nut and the outer shaft, and the meshing parts between the splines of the sleeve and the outer shaft. The tilt of the integrated object is prevented.

[0009]

【Example】

 An embodiment in which the present invention is applied to a steering device for an automobile will be described below with reference to the drawings. In the following description, the top and bottom of FIG. 1 are referred to as the top and bottom. Further, the left and right means toward the front with reference to the vertical direction of the paper surface of FIG.

FIG. 1 shows a telescopic operation portion of a steering device having a tilt operation function in addition to a telescopic operation function, and FIGS. 2 and 3 show the respective parts.

In FIGS. 1 to 3, a tilt bracket (2) is attached to a rear portion of a fixed bracket (1) fixed to a vehicle body so as to be vertically rotatable by a connecting pin (3). The front end of the column tube (4) is fixed to the rear end of the tilt bracket (2).

A hollow outer shaft (6) forming a steering shaft (5) is rotatably supported in the column tube (4) via ball bearings (7) and (8). In the rear part of the outer shaft (6), the front part of the hollow inner shaft (9), which also constitutes the steering shaft (5), is inserted from the rear, and the steering wheel (12) is installed at the rear end part of the inner shaft (9). Is installed. Further, a nut (10) having a right-handed screw (10a) and a sleeve (11) are inserted in the front portion inside the outer shaft (6) with the former as the front side. The inner shaft (9) and the sleeve (11) have a right-hand thread (13a) formed on the outer peripheral surface of the front end and a left-hand thread (13b) formed on the outer peripheral surface of the rear end. The rod (13) is threaded. A front portion of the rattling adjustment rod (13) is projected forward from the inner shaft (9), and a right screw (13a) at the front end portion thereof is screwed into a nut (10). Between the inner shaft (9) and the sleeve (11) and between the nut (10) and the sleeve (11), the respective rattling prevention members (14 ) (15) is fitted.

On the inner peripheral surface of the outer shaft (6), serrations (16) are formed on the entire surface except the front end portion, and on the rear end portion where the serrations (16) are not formed. , The stopper (17) for restricting the retracted position of the inner shaft (9) is fixed. At the front end of the outer peripheral surface of the inner shaft (9), the rear end of the outer peripheral surface of the nut (10), and the front and rear ends of the outer peripheral surface of the sleeve (11), the inner shaft inner peripheral surface of the outer shaft (6) is serrated. The serrations (18), (19) and (20) are formed so as to mesh with the joint (16).

As shown in detail in FIG. 2, a taper hole (21) tapering toward the rear is formed at the front end of the inner shaft (9), and the periphery of the taper hole (21) is formed. In the portion, a plurality of slits (22) extending from the front end to the rear are formed at intervals in the circumferential direction. An annular groove (23) is formed on the outer peripheral surface of the inner shaft (9) at a portion rearward of the serration (18) and the tapered hole (21). A left-hand thread (9a) is formed on the inner peripheral surface of the inner shaft (9) over a specified length, and a left-hand thread (13b) at the rear end of the rattling adjustment rod (13). Is meshing with.

At the rear end of the nut (10), a taper hole (25) tapering forward is formed. A continuous hole (26) having a diameter equal to the small diameter portion of the tapered hole (25) is formed in front of the tapered hole (25). A plurality of slits (27) extending from the rear end to the front are formed in the nut (10) around the tapered hole (25) and the fool hole (26) at circumferential intervals. The front end of the nut (10) projects forward from the outer shaft (6), and a bolt (28) is screwed onto the tip of the nut (10) so that it abuts the stopper (17). Along with this, the flange (29) that restricts the retracted position of the inner shaft (9) is fixed. On the rear surface of the flange (29), an elastic shock absorbing member (30) that absorbs a shock when it comes into contact with the stopper (17) is attached.

The front and rear ends of the sleeve (11) are respectively formed with tapered holes (31) which are tapered from the tip to the other end. A plurality of slits (32) extending in the axial direction from both ends of the sleeve (11) are formed in the sleeve (11) around the tapered hole (31) at circumferential intervals. An annular groove (33) is formed in the outer peripheral surface of the sleeve (11) between the tapered holes (31).

At the front and rear axial ends of the first rattling prevention member (14) between the inner shaft (9) and the sleeve (11), there are tapered holes for the sleeve (11) and the inner shaft (9). (31) (21) is formed, and push-expanding portions (14a) (14b) are formed to push the peripheral portions of the tapered holes (31) (21). The peripheral surfaces of the push-out portions (14a) and (14b) are tapered spherical surfaces.

At the both axial front and rear ends of the second rattling prevention member (15) between the nut (10) and the sleeve (11), the tapered holes (25) of the nut (10) and the sleeve (11) are provided. Push-out portions (15a) and (15b) that fit inside the (31) and push out the portions around the taper holes (25) (31) are formed. The peripheral surfaces of the push-out portions (15a) and (15b) are also tapered spherical surfaces.

A flange (35) is rotatably attached via a ball bearing (36) to an intermediate portion of the length of the outer peripheral surface of the inner shaft (9). The flange (35) serves as a stopper that contacts the rear end of the column tube (4) and restricts the forward movement position of the inner shaft (9). On the front surface of the flange (35), an elastic shock absorbing member (37) that absorbs a shock when it comes into contact with the column tube (4) is attached.

The rear end portion of the telescopic operation screw shaft (38) extending forward and backward is fixed to the flange (35). The screw shaft (38) is passed through a housing (39) integrally formed on the lower side of the tilt bracket (2). On the left side of the wall of the housing (39) when viewed from the steering wheel (12) side, a telescopic operation electric motor (40) is fixed to the right so as to form a right angle with the screw shaft (38). As shown in FIG. 3, the motor shaft (41) penetrates the wall of the housing (39) and projects rightward, and the worm (42) is fixed to this part.

A telescopic operation screw nut (43) is arranged in the housing (39) and meshed with the screw shaft (38). The screw nut (43) is rotatably supported by the housing (39) via two front and rear ball bearings (44) and (45). A tooth (43a) that meshes with the tooth (42a) of the worm (42) is formed on the outer peripheral surface of the screw nut (43) between the ball bearings (44) and (45). Together with the worm (42), also serves as a worm wheel that constitutes the worm gear (46).

In the configuration as described above, the rattling adjustment rod (13) is rotated to the right when viewed from the steering wheel (12) side. Then, the right screw (10a) of the nut (10) and the right screw (13a) formed on the outer peripheral surface of the rattling adjustment rod (13) work to move the nut (10) to the rod (13). To move backwards. At the same time, the left screw (9a) formed on the inner peripheral surface of the inner shaft (9) and the left screw (13b) formed on the outer peripheral surface of the rattling adjustment rod (13) work together. The shaft (9) moves forward with respect to the rod (13). As a result, the nut (10) and the inner shaft (9) come close to each other, and the outer peripheral surfaces of the expansion portions (14a) and (14b) of the first rattling prevention member (14) move toward the sleeve (11). And, on the inner peripheral surface of the tapered hole (31) (21) of the inner shaft (9), the outer peripheral surface of the push expansion parts (15a) (15b) of the second rattling prevention member (15) is attached to the nut (10). And the inner peripheral surface of the tapered hole (25) (31) of the sleeve (11). A plurality of slits (32), (22) and (27) extending in the axial direction are formed in the surroundings of these tapered holes (31), (21) and (25), so that the rods are further extended in the same direction. When (13) is rotated, the expanded parts (14a) (14b) (15a) (15b) of the anti-rattle members (14) (15) allow the taper hole (21) of the inner shaft (9) to be released. ), The part around the tapered hole (25) of the nut (10), and the part around the tapered hole (31) of the sleeve (11) are pushed outward in the radial direction. This forces the outer serrations (18) (19) (20) of the inner shaft (9), nut (10) and sleeve (11) against the inner serrations (16) of the outer shaft (6). There will be less rattling in the meshing parts of. In this way, the outer shaft (6) and the inner shaft (9) are adjusted so that there is no rattling and that they slide smoothly in the axial direction.

Further, the sleeve (11) and the rattling prevention members (14) and (15) are tightened by the rattling adjustment rod (13), the nut (10) and the inner shaft (9), and these are fixed. Be integrated. Then, this integrated product is engaged between the outer shaft (6) and inner shaft (9) serrations (16) (18), and the outer shaft (6) and nut (10) serrations (16) (19). Since it is supported by the meshing portion and the meshing portion between the outer shaft (6) and the serrations (16) (20) of the sleeve (11), the inclination of this integrated product is prevented. As a result, the inclination of the inner shaft (9) with respect to the outer shaft (6) is prevented.

In the above-mentioned electric telescopic steering device, when performing telescopic operation, the rotation of the telescopic motor (40) is reduced by the worm gear (46) and transmitted to the screw nut (43). Causes the screw nut (43) to rotate. Then, the rotation of the screw nut (43) is converted into a linear movement in the axial direction of the screw shaft (38). As a result, a force in the front-rear direction acts on the flange (35), and the inner shaft (9) moves back and forth with respect to the outer shaft (6) to perform telescopic operation.

In the above description, the peripheral surfaces of the push-spreading portions (14a) (14b) (15a) (15b) of the rattling prevention members (14) (15) are spherical, but the invention is not limited to this. For example, it may have a tapered conical surface.

[0026]

[Effect of the device]

 According to the electric telescopic steering device of the present invention, as described above, the rattling of the outer shaft spline and the inner shaft spline is prevented, and the inner shaft is prevented from tilting. It Therefore, the rigidity of the steering shaft is improved and rattling is prevented.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a configuration of a main part of an electric telescopic steering device according to the present invention.

FIG. 2 is an enlarged sectional view of a front portion of FIG.

FIG. 3 is an enlarged cross-sectional view of a portion of the electric motor shown in FIG.

[Explanation of symbols]

 5 Steering shaft 6 Hollow outer shaft 9 Hollow inner shaft 9a Left-hand screw 10 Nut 10a Right-hand screw 11 Sleeve 13 Shaft adjusting rod 13a Right-hand screw 13b Left-hand screw 14 Anti-rattle member 14a Push-expanding part 14b Push-expanding part 15 Anti-rattle member 15a Pushing and expanding part 15b Pushing and spreading part 16 Serration 18 Serration 19 Serration 20 Serration 21 Tapered hole 22 Slit 25 Tapered hole 27 Slit 31 Tapered hole 32 Slit

Claims (1)

[Scope of utility model registration request] 1. A steering shaft comprising: a hollow outer shaft having a spline formed on an inner circumference thereof; In the electric telescopic steering device in which the steering shaft is made to expand and contract by the rotation of the electric motor, a rattling adjustment rod with a screw formed at the front end is passed through the inner shaft. , The front part of the rattling adjustment rod is projected forward from the inner shaft, and a spline that meshes with the spline of the outer shaft is formed on the outer peripheral surface in the part in front of the inner shaft around the rattling adjusting rod. The sleeve is fitted and the rattle adjustment rod A nut with a spline that meshes with the spline of the outer shaft is formed on the outer peripheral surface of the screw.The nut is fitted around the rattling adjustment rod between the inner shaft and the sleeve and between the sleeve and the nut. An anti-sticking member is fitted, and tapered holes are formed at the front end of the inner shaft, the front and rear ends of the sleeve, and the rear end of the nut, each tapering toward the other end. A plurality of slits extending in the axial direction from the end portion are formed, and both front and rear end portions of the rattling prevention member are formed with a push-expanding portion that fits in the taper and pushes and expands a portion around the tapered hole, On the inner peripheral surface of the inner shaft, a screw with a twist direction different from that of the nut is formed, and on the outer peripheral surface of the rattling adjustment rod, Electric telescopic steering device screw meshing with shift of thread is formed.