JP2006205749A - Steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering device for improving steering stability and preventing large load to a pinion shaft by reducing vibration and bending moment applied to the pinion shaft and a pinion at a lower end of an extension shaft caused by vibration of wheels and vehicle body. <P>SOLUTION: A heavy double Cardan constant velocity universal joint 4 is vibrated by vibration of the wheels and the vehicle body at the time of traveling, but since an elastic shaft coupling 7 is interposed at a substantially intermediate position of an axial length of the extension shaft 5, the vibration of the universal joint 4 is absorbed by an elastic body 72 of the elastic shaft coupling 7. As a result, the vibration and bending moment applied to the pinion shaft 53 and the pinion 54 are reduced, and thereby steering stability is improved, and the large load to the pinion shaft 53 can be prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a steering device, and more particularly, to a steering device that reduces vibration and bending moment applied to a pinion of an extension shaft that transmits rotation of a steering wheel to a rack of a steering gear.

  As a steering apparatus having such an extension shaft, there is a steering apparatus disclosed in Patent Document 1. In the steering device of Patent Document 1, an intermediate shaft is connected to the lower end of the steering shaft connected to the steering wheel in order to transmit the rotation of the steering wheel that is not in a straight line to the extension shaft, and a universal joint is connected to the lower end of the intermediate shaft. The extension shaft is connected via

  When vibration of a wheel or a vehicle body is applied to the steering device, the universal joint at the upper end of the extension shaft vibrates, and a large bending moment and vibration are applied to the pinion shaft at the lower end of the extension shaft due to the vibration of the universal joint. Therefore, not only the steering stability of the steering wheel is lowered, but a large load may be applied to the pinion shaft. In particular, in a steering device using a heavy double cardan type constant velocity universal joint, the bending moment applied to the pinion shaft becomes large, and thus the problem tends to increase.

JP 2003-72574 A

  The present invention reduces the vibration and bending moment applied to the pinion shaft and pinion at the lower end of the extension shaft due to the vibration of the wheel and the vehicle body, improves steering stability, and prevents a heavy load on the pinion shaft. It is an object to provide an apparatus.

  The above problem is solved by the following means. In other words, the first aspect of the invention includes a column that rotatably supports a steering shaft having a steering wheel mounted on the rear side of the vehicle body, an intermediate shaft that is coupled to the lower side of the steering shaft, and a pinion that meshes with a rack of the steering gear. An extension shaft formed on the lower side, a socket yoke that connects the upper side of the extension shaft and the lower side of the intermediate shaft, and a pin yoke are connected to both ends of the annular coupling yoke via a cross shaft, and the socket yoke And a double cardan type constant velocity universal joint in which the tip end portions of the pin yoke are connected by a spherical bearing, an upper side extension shaft formed on the upper side of the extension shaft, and a lower side of the extension shaft. An upper extension shaft, an elastic body connecting the lower end of the upper extension shaft and the upper end of the lower extension shaft, and a stopper pin, and when the rotational torque applied from the steering wheel to the steering shaft becomes larger than a predetermined value, A steering apparatus comprising an elastic shaft coupling to which rotational torque is transmitted via a stopper pin.

  A second invention is the steering device according to the first invention, wherein the elastic shaft coupling is attached at a substantially middle position of the axial length of the extension shaft.

  According to a third aspect of the present invention, in the steering apparatus according to the first or second aspect of the invention, the intermediate shafts are slidable relative to each other in the axial direction and can transmit rotational torque. And an intermediate outer shaft.

  In the steering device of the present invention, the extension shaft is composed of the upper side extension shaft and the lower side extension shaft, and the lower end of the upper side extension shaft and the upper end of the lower side extension shaft are connected by the elastic shaft joint, so that the weight is large. The vibration of the double cardan type constant velocity universal joint is absorbed by the elastic shaft joint. Accordingly, since vibration and bending moment applied to the pinion shaft and pinion are reduced, steering stability is improved, and a large load on the pinion shaft and pinion can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall perspective view showing a state in which the steering device of the present invention is attached to a vehicle. FIG. 2 is a partial cross-sectional side view showing a main part of the steering device according to the embodiment of the present invention. 3 is an AA enlarged sectional view showing the double cardan type constant velocity universal joint of FIG. FIG. 4 is an enlarged cross-sectional view showing the elastic shaft coupling of FIG.

  As shown in FIGS. 1 and 2, a hollow cylindrical column 1 is fixed to a vehicle body, and a steering shaft 12 is pivotally supported on the column 1 so as to be rotatable. A steering wheel 13 is mounted on the steering shaft 12 at the right end (rear side of the vehicle body), and the intermediate shaft 3 is connected to the left end (front side of the vehicle body) of the steering shaft 12 via the cardan joint 2.

  A double cardan type constant velocity universal joint 4 is connected to the left end of the intermediate shaft 3, and an extension shaft 5 is connected to the double cardan type constant velocity universal joint 4. The pinion 54 of the pinion shaft 53 connected to the lower end (lower side) of the extension shaft 5 is engaged with the rack 61 of the steering gear 6. The extension shaft 5 is configured by connecting the lower end of the upper side extension shaft 51 and the upper end of the lower side extension shaft 52 by an elastic shaft joint 7.

  The elastic shaft joint 7 is provided at a substantially middle position in the axial direction of the extension shaft 5. The pinion shaft 53 and the pinion 54 are configured separately from the extension shaft 5, and are fastened and fixed to a joint 523 formed at the lower end of the lower side extension shaft 52.

  When the driver rotates the steering wheel 13, the rotational force is transmitted through the steering shaft 12, the cardan joint 2, the intermediate shaft 3, the double cardan type constant velocity universal joint 4, the extension shaft 5, and the pinion 54 of the pinion shaft 53. It is transmitted to the steering gear 6 and the tie rod 62 can be moved via the rack and pinion mechanism to change the steering angle of the wheel.

  The intermediate shaft 3 includes a solid intermediate inner shaft 31 in which a male spline is formed on the vehicle body rear side (upper side), and a hollow cylindrical intermediate outer shaft 32 in which a female spline is formed on the vehicle body front side (lower side). The male spline of the intermediate inner shaft 31 is slidably fitted to the female spline of the intermediate outer shaft 32 so that rotational torque can be transmitted. The rear side of the intermediate inner shaft 31 is connected to the cardan joint 2, and the front side of the intermediate outer shaft 32 is connected to the double cardan type constant velocity universal joint 4.

  FIG. 3 shows details of the double cardan type constant velocity universal joint 4. This double cardan type constant velocity universal joint 4 is a pin socket type double cardan type constant velocity universal joint. That is, the socket yoke 41 and the pin yoke 42 arranged in the axial direction are coupled to the annular coupling yoke 45 at the center via the cross shafts 43 and 44, respectively.

  The pin yoke 42 is attached to the upper end of the upper side extension shaft 51, and the socket yoke 41 is attached to the lower end of the intermediate outer shaft 32. A cylindrical sleeve 411 formed at the front end of the socket yoke 41 is introduced into the coupling yoke 45, and a pin 421 is introduced into the inner periphery of the cylindrical sleeve 411 at the front end of the pin yoke 42. Is formed.

  A spherical seat 412 is fitted to the inner periphery of the cylindrical sleeve 411 of the socket yoke 41, and a spherical body 423 that is supported by the pin 421 of the pin yoke 42 so as to be rotatable and slidable in the axial direction via the needle bearing 422. The spherical bearing 412 is slidably contacted to constitute a spherical bearing. Further, a bottomed cylindrical portion 424 is formed on the pin 421 of the pin yoke 42, and a flange-shaped spring bearing that extends radially inward separately from the spherical body 423 on the opening side of the bottomed cylindrical portion 424. A member 425 is formed. A compression coil spring 426 extending in the axial direction is mounted between the bottomed cylindrical portion 424 and the spring receiving member 425, and urges the spherical body 423 so as to be always in close contact with the spherical seat 412.

  Next, the elastic shaft coupling 7 will be described. As shown in FIG. 4, the elastic shaft coupling 7 includes an inner sleeve 71, an elastic body 72, an outer sleeve 73, and a stopper pin 74. The stopper pin 74 is made of metal, and is fixed to the upper end portion of the lower side extension shaft 52 over the diameter direction. For this reason, a pair of through-holes 521 and 521 are formed at two positions opposite to the diametrical direction at the upper end portion of the lower-side extension shaft 52 so as to penetrate in the diametrical direction.

  In addition, the positions of two intermediate portions of the stopper pin 74 are supported in the through holes 521 and 521. The outer diameters at both ends of the stopper pin 74 are slightly larger than the inner diameters of the through holes 521 and 521. In this state, both end portions of the stopper pin 74 protrude outward in the diameter direction from the outer peripheral surface of the lower side extension shaft 52.

  The elastic body 72 is made of an elastomer material such as rubber and has a cylindrical shape. Further, an inner sleeve 71 and an outer sleeve 73, each made of metal and formed in a cylindrical shape, are arranged concentrically with each other. Then, the outer peripheral surface of the inner sleeve 71 and the inner peripheral surface of the elastic body 72 are coupled by baking or bonding, and the inner peripheral surface of the outer sleeve 73 and the outer peripheral surface of the elastic body 72 are similarly coupled. Yes.

  The inner sleeve 71 is fitted and fixed to the outer periphery 522 of the upper end portion of the lower extension shaft 52, and the outer sleeve 73 is fixed to the inner circumference 512 of the upper extension shaft 51.

  In addition, the inner sleeve 71, the elastic body 72, the outer sleeve 73, and a part of the cylindrical portion 513 of the upper side extension shaft 51 have a diameter that matches with the through holes 521 and 521 formed in the lower side extension shaft 52 described above. A pair of through holes 711, 721, 731, and 511 are formed at two positions opposite to each other in the diametrical direction. Then, the respective through holes 711, 721, 731 formed in the inner sleeve 71, the elastic body 72, the outer sleeve 73, and the upper side extension shaft 51 at portions near both ends of the stopper pin 74 supported by the lower side extension shaft 52. 511 is inserted.

  The inner diameter of the through hole 711 formed in the inner sleeve 71 is substantially the same as the inner diameter of the through holes 521 and 521 formed in the lower extension shaft 52. In contrast, the inner diameters of the through holes 721 and 731 formed in the elastic body 72 and the outer sleeve 73 and the inner diameter of the through hole 511 formed in the cylindrical portion 513 of the upper side extension shaft 51 are the same as the lower side extension. The inner diameter of each of the through holes 521 and 521 formed in the shaft 52 is larger.

  Accordingly, the outer peripheral surfaces of both ends of the stopper pin 74, the through holes 721 and 731 formed in the elastic body 72 and the outer sleeve 73, and the inner peripheral surface of the through hole 511 formed in the upper side extension shaft 51. A gap is formed between the two.

  The operation of the elastic shaft joint 7 configured as described above is as follows. When the rotational torque applied from the steering wheel 13 to the steering shaft 12 is small, both end portions of the stopper pin 74 are present in the neutral position or slightly offset from the neutral position in the through hole 511 of the upper side extension shaft 51. To do. In this state, a gap is formed over the entire circumference between the outer peripheral surfaces of both ends of the stopper pin 74 and the inner peripheral surfaces of the through holes 511 and 511, and both end portions of the stopper pin 74 are There is no contact with the inner surfaces of the through holes 511 and 511.

  At this time, the small rotational torque is transmitted from the lower extension shaft 52 to the pinion shaft 53, the pinion 54, the rack 61, and the steering gear 6 through the outer sleeve 73, the elastic body 72, and the inner sleeve 71.

  The heavy double cardan type constant velocity universal joint 4 vibrates due to the vibration of the wheel or the vehicle body during traveling, but the elastic shaft joint 7 is interposed at a substantially intermediate position in the axial direction length of the extension shaft 5. The vibration of the double cardan type constant velocity universal joint 4 is absorbed by the elastic body 72 of the elastic shaft joint 7.

  Therefore, since vibration and bending moment applied to the pinion shaft 53 and the pinion 54 are reduced, steering stability is improved, and a large load on the pinion shaft 53 can be prevented. As shown in the embodiment of the present invention, if the elastic shaft coupling 7 is interposed at a substantially intermediate position of the axial length of the extension shaft 5, both the amplitude of the vibration applied to the pinion shaft 53 and the bending moment are appropriately suppressed. It becomes possible to do.

  When the rotational torque applied to the steering shaft 12 from the steering wheel 13 is large, such as when giving a large steering angle to the front wheels, the outer peripheral surfaces of both ends of the stopper pin 74 and the through holes 511, 731, The inner peripheral surface of 721 contacts. As a result, most of the rotational torque applied from the steering wheel 13 to the steering shaft 12 is transmitted to the lower extension shaft 52 via the stopper pin 74. In this state, the rotational torque transmitted through the elastic body 72 is limited, and an unreasonable force acts on the elastic body 72 and the durability of the elastic body 72 may be impaired. Absent.

  In the above-described embodiment, the pinion shaft 53 and the pinion 54 are configured separately from the extension shaft 5, and the pinion shaft 53 is connected to the lower end of the lower side extension shaft 52, but the pinion shaft 53 and the pinion 54 are lower. You may comprise integrally with the side extension shaft 52. FIG.

  In the above embodiment, the steering shaft 12 and the intermediate inner shaft 31 are connected by the cardan joint 2. However, when the steering shaft 12 and the intermediate inner shaft 31 are arranged in a straight line without an assembly error, the cardan joint is used. 2 can be omitted. In the above-described embodiment, an example is described in which the present invention is applied to a steering device that does not adjust the position of the steering wheel 13 according to the physique of the driver. However, at least one of the tilt position and the telescopic position of the steering wheel 13 can be adjusted. The present invention may be applied to various steering devices.

It is a whole perspective view which shows the state which attached the steering device of this invention to the vehicle. It is the side view which carried out the section which shows the principal part of the steering device of the present invention. It is an AA expanded sectional view which shows the double cardan type constant velocity universal joint of FIG. It is an expanded sectional view which shows the elastic shaft coupling of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Column 12 Steering shaft 13 Steering wheel 2 Cardan joint 3 Intermediate shaft 31 Intermediate inner shaft 32 Intermediate outer shaft 4 Double cardan type constant velocity universal joint 41 Socket yoke 411 Cylindrical sleeve 412 Spherical seat 42 Pin yoke 421 Pin 422 Needle bearing 423 Spherical body 424 Cylindrical part with bottom 425 Spring receiving member 426 Compression coil spring 43 Cross shaft 44 Cross shaft 45 Coupling yoke 5 Extension shaft 51 Upper side extension shaft 511 Through hole 512 Inner circumference 513 Cylindrical part 52 Lower side extension shaft 521 Through hole 522 Outer circumference 523 Joint 53 Pinion shaft 54 Pinion 6 Steering gear 61 Rack 62 Tie rod 7 Elastic shaft joint 71 Inner sleeve 711 Through hole 72 Elastic body 721 Through hole 73 Outer sleeve 731 Through hole 74 Stopper pin

Claims (3)

A column that rotatably supports a steering shaft with a steering wheel mounted on the rear side of the vehicle body,
An intermediate shaft connected to the lower side of the steering shaft,
An extension shaft with a pinion meshing with the steering gear rack on the lower side,
A socket yoke and a pin yoke that connect the upper side of the extension shaft and the lower side of the intermediate shaft are connected to both ends of the annular coupling yoke via a cross shaft, and the tip ends of the socket yoke and the pin yoke are spherical bearings. Double cardan type constant velocity universal joint, connected by
An upper extension shaft formed on the upper side of the extension shaft,
Lower extension shaft formed on the lower side of the extension shaft,
An elastic body connecting the lower end of the upper side extension shaft and the upper end of the lower side extension shaft and a stopper pin are provided, and when the rotational torque applied from the steering wheel to the steering shaft becomes larger than a predetermined value, A steering apparatus comprising an elastic shaft coupling to which rotational torque is transmitted. The steering apparatus according to claim 1, wherein
The steering device according to claim 1, wherein the elastic shaft coupling is attached at a substantially intermediate position in the axial length of the extension shaft. In the steering device according to claim 1 or 2,
The steering device according to claim 1, wherein the intermediate shaft is configured to include an intermediate inner shaft and an intermediate outer shaft that are slidable relative to each other in the axial direction and capable of transmitting rotational torque.

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