JP3800159B2 - Telescopic shaft for vehicle steering - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a telescopic shaft for vehicle steering that realizes a stable sliding load, reliably prevents rattling and can transmit torque in a highly rigid state.
[0002]
[Prior art]
FIG. 12 shows a general automobile steering mechanism. In the drawing, a and b are telescopic axes. The telescopic shaft a is a spline fit between a male shaft and a female shaft. The telescopic shaft a absorbs axial displacement that occurs when the automobile travels, and the Performance that does not transmit displacement or vibration is required. In such a performance, the vehicle body has a sub-frame structure, and a part c for fixing the upper part of the steering mechanism and a frame e to which the steering rack d is fixed are separated, and an elastic body f such as rubber is provided between them. Generally, it is required in the case of a structure that is fastened and fixed via As another case, when the steering shaft joint g is fastened to the pinion shaft h, an operator may need to have a telescopic function so that the telescopic shaft is once contracted and then fitted and fastened to the pinion shaft h. . Further, the telescopic shaft b at the upper part of the steering mechanism is a spline-fitting of the male shaft and the female shaft, and the telescopic shaft b is in an optimal position for the driver to drive the automobile. Therefore, the function of moving the position of the steering wheel i in the axial direction and adjusting the position is required, and thus the function of expanding and contracting in the axial direction is required. In all the cases described above, the telescopic shaft is required to reduce the rattling noise of the spline, to reduce the rattling on the steering wheel, and to reduce the sliding resistance during the axial sliding operation. Is done.
[0003]
Therefore, in FIGS. 1 to 5 of Patent Document 1, a plurality of preload elastic bodies are provided 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. A plurality of sets of torque transmission members (spherical bodies) are fitted via (plate springs).
[0004]
As a result, when torque is not transmitted (sliding), the torque transmission member (spherical body) is preloaded by the leaf spring to such an extent that the female shaft is not rattled. It is possible to prevent backlash between the male shaft and the female shaft, and the male shaft and the female shaft can slide in the axial direction with a stable sliding load without backlash.
[0005]
In addition, the torque transmission member (spherical body) can be constrained in the circumferential direction by a leaf spring during torque transmission, so that the male shaft and female shaft are prevented from rattling in the rotational direction and have high rigidity. Torque can be transmitted in this state.
[0006]
[Patent Document 1]
German Patent Invention DE 3730393C2 [0007]
[Problems to be solved by the invention]
In the structure disclosed in FIGS. 1 to 5 of Patent Document 1 described above, one leaf spring for preloading a set of torque transmission members (spherical bodies) and another set of torque transmission members adjacent in the circumferential direction ( The other leaf spring for preloading the spherical body is connected in the circumferential direction by an arc-shaped connecting portion extending in the circumferential direction.
[0008]
This connecting portion is for applying a tensile force or a compressive force to the two leaf springs to generate a preload on the two leaf springs.
[0009]
The structure disclosed in FIG. 1 to FIG. 5 of Patent Document 1 provided with this connecting portion is preloaded by a plurality of leaf springs with respect to all of a plurality of sets of torque transmitting members (spherical bodies) arranged in the circumferential direction. If you want, you can apply.
[0010]
However, if there is a set of torque transmission members that are not preloaded by the leaf springs among a plurality of sets of torque transmission members arranged in the circumferential direction, for example, a set of torque transmission members that are preloaded by the leaf springs and a set that is not preloaded by the leaf springs. In the case where the torque transmission members are alternately arranged in the circumferential direction, the structure disclosed in FIGS. 1 to 5 of Patent Document 1 including an arc-shaped connecting portion extending in the circumferential direction can be applied. Can not.
[0011]
Moreover, in the structure disclosed in FIG. 1 to FIG. 5 of Patent Document 1 provided with this connecting portion, an arc-shaped connecting portion is interposed between the male shaft and the female shaft in the radial direction. Since a space for the arc-shaped connecting portion is required, the female shaft may be diametrically expanded to increase the radial dimension of the female shaft.
[0012]
Furthermore, in FIG. 8 of patent document 1, the several leaf | plate spring which preloads several sets of rolling elements is not connected by the above connection parts.
[0013]
However, in this case, when the telescopic shaft is assembled, it is necessary to insert and assemble a plurality of leaf springs separately, resulting in an increase in assembly cost.
[0014]
The present invention has been made in view of the circumstances as described above, achieves a stable sliding load, reliably prevents backlash in the rotational direction, and can transmit torque in a highly rigid state. In addition, even when connecting the preload elastic body of the torque transmission member, it is possible to reduce the number of parts, shorten the assembly time, and reduce the manufacturing cost while reducing the size without expanding the female shaft in the radial direction. An object of the present invention is to provide a telescopic shaft for vehicle steering that can be used.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, a vehicle steering telescopic shaft according to claim 1 of the present invention is incorporated in a steering shaft of a vehicle, and a male shaft and a female shaft are fitted in a non-rotatable and slidable manner. In the telescopic shaft for steering,
At least two sets of torque transmission members are disposed on at least two sets of interposing portions formed on the outer peripheral surface of the male shaft and the inner peripheral surface of the female shaft via at least two preload elastic bodies,
The at least two preload elastic bodies are connected by a connecting portion disposed at or near an end of the male shaft.
[0016]
Thus, according to claim 1, the at least two preload elastic bodies are connected by the connecting portion disposed at or near the end portion of the male shaft, and extend in the circumferential direction as in the prior art. Since it is not an arc-shaped connecting portion, the female shaft can be made compact without expanding the diameter in the radial direction, and since each elastic body is integrally connected by the connecting portion, the number of parts can be reduced. It is possible to reduce the manufacturing time by reducing the assembly time.
[0017]
Further, the telescopic shaft for vehicle steering according to claim 2 is incorporated in the steering shaft of the vehicle, and the telescopic shaft for vehicle steering is configured such that the male shaft and the female shaft are slidably fitted to each other so as not to rotate.
At least two sets of torque transmission members are disposed on at least two sets of interposing portions formed on the outer peripheral surface of the male shaft and the inner peripheral surface of the female shaft via at least two preload elastic bodies,
The at least two preload elastic bodies are connected by a ring-shaped connecting portion disposed along an axial annular surface facing the axial direction of the male shaft.
[0018]
Thus, according to claim 2, the at least two preload elastic bodies are connected by the ring-shaped connecting portion arranged along the axial annular surface facing the axial direction of the male shaft, Since it is not an arc-shaped connecting portion extending in the circumferential direction as in the prior art, it is possible to achieve compactness without expanding the female shaft in the radial direction, and each elastic body is integrally connected by the connecting portion. Therefore, the number of parts can be reduced, the assembly time can be shortened, and the manufacturing cost can be reduced.
[0019]
Furthermore, the telescopic shaft for vehicle steering according to claim 3 is characterized in that a small-diameter portion formed at the end of the male shaft passes through the ring-shaped connecting portion.
[0020]
Thus, according to Claim 3, the small diameter part formed in the edge part of the male shaft has penetrated the ring-shaped connection part. Therefore, when assembling the elastic body for radial preload, the small diameter part at the end of the male shaft is inserted into the ring-shaped connecting part to serve as a guide for this assembling. Therefore, the assembly time can be shortened and the manufacturing cost can be reduced.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a telescopic shaft for vehicle steering according to an embodiment of the present invention will be described with reference to the drawings.
[0022]
(First embodiment)
FIG. 1 is a longitudinal sectional view of a telescopic shaft for vehicle steering according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line XX of FIG.
[0023]
As shown in FIG. 1, the vehicle steering telescopic shaft (hereinafter referred to as the telescopic shaft) is composed of a male shaft 1 and a female shaft 2 which are slidably fitted to each other so as not to rotate.
[0024]
As shown in FIG. 2, three axial grooves 3 that are equally arranged at intervals of 120 degrees in the circumferential direction are formed to extend on the outer peripheral surface of the male shaft 1. In addition, on the outer peripheral surface of the male shaft 1, there are three substantially circular arc-shaped axial grooves 4 that are equally spaced at 120 degree intervals in the circumferential direction between the three axial grooves 3 in the circumferential direction. Is formed to extend.
[0025]
On the inner peripheral surface of the female shaft 2, three substantially arc-shaped axial grooves 5 that are equally arranged at intervals of 120 degrees in the circumferential direction are formed to extend. Further, on the inner peripheral surface of the female shaft 2, there are three substantially arc-shaped axial grooves between the circumferential directions of the three axial grooves 5 and equally spaced at 120 degree intervals in the circumferential direction. 6 extends and is formed.
[0026]
The axial grooves 3 and 5 constitute three sets of first interposing parts for three sets of spherical bodies 7 to be described later, and the axial grooves 4 and 6 are three sets of cylindrical bodies 8 to be described later. For this reason, three sets of second intervention parts are configured. These three sets of axial grooves 3 and 5 (first interposition part) and three sets of axial grooves 4 and 6 (second interposition part) are alternately arranged in the circumferential direction. Are evenly spaced at 60 degree intervals.
[0027]
The first torque transmission device includes three elastic bodies (plate springs) having a wavy shape for preload between the three axial grooves 3 of the male shaft 1 and the three axial grooves 5 of the female shaft 2. ) 9 through the first set of three torque transmissions that rotate when the male shaft 1 and the female shaft 2 move in the axial direction relative to each other and transmit torque while being constrained by the leaf spring 9 during rotation. A member (spherical body) 7 is configured so as to be capable of rolling.
[0028]
The second torque transmission device includes an axial relative relationship between the male shaft 1 and the female shaft 2 between the three axial grooves 4 of the male shaft 1 and the three axial grooves 6 of the female shaft 2, respectively. Three sets of second torque transmission members (cylindrical bodies) 8 that allow movement and transmit torque during rotation are configured to be slidably interposed.
[0029]
The leaf spring 9 preloads the spherical body 7 and the cylindrical body 8 with respect to the female shaft 2 without any backlash when torque is not transmitted, and elastically deforms when the torque is transmitted, so that the spherical body 7 and the male shaft 1 are deformed. It acts to restrain the circumferential direction between the female shafts 2.
[0030]
In the telescopic shaft configured as described above, the spherical body 7 and the cylindrical body 8 are interposed between the male shaft 1 and the female shaft 2, and the spherical body 7 and the cylindrical body 8 are connected to the female shaft 2 by the leaf spring 9. Since it is preloaded to the extent that there is no backlash, it is possible to reliably prevent backlash between the male shaft 1 and the female shaft 2 when torque is not transmitted, and the male shaft 1 and the female shaft 2 are When moving relative to each other, the male shaft 1 and the female shaft 2 can slide in the axial direction with a stable sliding load without backlash.
[0031]
In addition, if the sliding surface is pure sliding as in the prior art, the preload load for preventing rattling can only be kept to a certain extent. That is, the sliding load is the friction coefficient multiplied by the preload, and if the preload is increased to prevent rattling and improve the rigidity of the telescopic shaft, the sliding load will increase. It had fallen into a vicious circle.
[0032]
In this respect, in this embodiment, since the mechanism by rolling is partially adopted, the preload load can be increased without causing a significant increase in sliding load. As a result, it was possible to achieve the prevention of rattling and the improvement of rigidity, which could not be achieved in the past, without increasing the sliding load.
[0033]
At the time of torque transmission, the three sets of leaf springs 9 are elastically deformed to restrain the three sets of spherical bodies 7 in the circumferential direction between the male shaft 1 and the female shaft 2 and between the male shaft 1 and the female shaft 2. Three sets of mounted cylinders 8 play the main role of torque transmission.
[0034]
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, the torque transmission load between the male shaft 1, the leaf spring 9, the spherical body 7 and the female shaft 2 and the torque transmission load between the male shaft 1, the cylindrical body 8 and the female shaft 2 are balanced. Torque is transmitted.
[0035]
As the torque further increases, the clearance in the rotational direction of the male shaft 1 and the female shaft 2 via the cylindrical body 8 is greater than that of the male shaft 1, leaf spring 9, spherical body 7, female via the spherical body 7. Since the clearance is smaller than the clearance between the shafts 2, the cylindrical body 8 receives a reaction force stronger than the spherical body 7, and the cylindrical body 8 mainly transmits torque to the female shaft 2. 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.
[0036]
The spherical body 7 may be a ball. The cylindrical body 8 may be a needle roller.
[0037]
Since the needle roller 8 receives the load by line contact, the needle roller 8 has various effects such as a lower contact pressure than the ball 7 that receives the 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.
-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.
[0038]
As described above, the needle roller 8 serves as a key for transmitting torque 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. Advantages compared to conventional spline fitting are 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 need to be further reduced. At this time, if the surface treatment is applied only to the needle roller, its sliding characteristics can be changed. , Can correspond to various applications.
・ Products with different outer diameters of needle rollers can be manufactured in units of several microns at low cost, so the clearance 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.
[0039]
On the other hand, the following items are superior to the structure in which all the rows of needle rollers are slid in that the balls are partially employed.
・ Sliding load can be kept low because of low frictional resistance.
・ Preload can be increased, and long-term rattling and high rigidity can be achieved at the same time.
[0040]
FIG. 3 is an enlarged vertical sectional view in which the main part of FIG. 1 is enlarged. 4 is a cross-sectional view taken along line YY of FIG. FIG. 5 is a perspective view of an elastic body (plate spring) connected by a connecting portion.
[0041]
As shown in FIG. 3, a small diameter portion 1 a is formed at the end of the male shaft 1. The small diameter portion 1 a is provided with a stopper plate 10 that restricts the axial movement of the needle roller 8. The stopper plate 10 includes an axial preload elastic body 11 and a pair of flat plates 12 and 13 that sandwich the axial preload elastic body 11.
[0042]
That is, in the present embodiment, the stopper plate 10 is fitted into the small diameter portion 1a in the order of the flat plate 13, the axial preloading elastic body 11, and the flat plate 12, and then the end portion 1b of the small diameter portion 1a is crimped. The small diameter portion 1a is firmly fixed.
[0043]
As a result, the stopper plate 10 can be appropriately preloaded by the axial preload elastic body 11 so that the flat roller 13 is brought into contact with the needle roller 8 so as not to move in the axial direction.
[0044]
The axial preload elastic body 11 is made of rubber, resin, or a plate spring made of a steel plate. The axial preload elastic body 11 and the flat plates 12 and 13 may be separate bodies, but are preferably integrally formed in consideration of ease of assembly.
[0045]
For example, if the elastic body 11 for axial preload is rubber, it can be integrated if it is made by vulcanizing the flat plates 12 and 13, etc., so that it is easy to assemble and a low-cost product can be made.
[0046]
Further, when the elastic body 11 for axial preload is made of resin, the corrugated shape can be integrated with the flat plates 12 and 13 to obtain the same merit.
[0047]
Further, the flat plates 12 and 13 are made of a steel plate, a resin, or a steel plate formed with a resin film.
[0048]
Further, the axial grooves 3 and 4 of the male shaft 1 are substantially perpendicular to the axial direction and have axially perpendicular surfaces 14 and 15 that contact the ball 7 and the needle roller 8.
[0049]
As described above, one side of the needle roller 8 is restricted from moving in the axial direction by the stopper plate 10 provided on the small diameter portion 1a of the male shaft 1, while the other side of the needle roller 8 is perpendicular to the axial direction. Abutting on the surface 15, the movement in the axial direction is restricted.
[0050]
The stopper plate 10 is pre-pressurized moderately so that the needle roller 8 is not moved in the axial direction by the elastic member 11 for axial pre-load by causing the flat plate 13 to contact the needle roller 8.
[0051]
Accordingly, the needle roller 8 can be appropriately preloaded and fixed without any gap in the axial direction, and the needle roller 8 is not moved in the axial direction when the male shaft 1 and the female shaft 2 slide against each other. It is possible to reliably prevent the generation of unpleasant noises such as “knack”.
[0052]
Further, the axial grooves 3 and 4 of the male shaft 1 are substantially perpendicular to the axial direction, and have axially perpendicular surfaces 14 and 15 that contact the ball 7 and the needle roller 8. The right-angled surface 15 can restrict the movement of the ball 7 and the needle roller 8 in the axial direction without providing a separate member. Therefore, the number of parts can be reduced to reduce the manufacturing cost, and further, since no separate member is used, the weight and the size can be reduced.
[0053]
Next, in the present embodiment, as shown in FIGS. 3 to 5, the three leaf springs 9 for preloading the three sets of balls 7 are connected by a ring-shaped connecting portion 20.
[0054]
That is, as shown in FIG. 3, an annular surface 21 of the step is formed in the small diameter portion 1 a at the end of the male shaft 1. A ring-shaped connecting portion 20 is fitted to the small-diameter portion 1a, and the ring-shaped connecting portion 20 is disposed along the annular surface 21 of the step.
[0055]
As long as the annular surface 21 of the step is an axial annular surface facing the axial direction of the male shaft 1, its shape or the like is not limited.
[0056]
The ring-shaped connecting portion 20 is connected to the axial end portions of the three leaf springs 9 at three locations on the periphery thereof. That is, as shown in FIG. 5, the ring-shaped connecting portion 20 is integrally formed with three leaf springs 9 extending in the axial direction.
[0057]
Therefore, although the ball 7 and the needle roller 8 are combined, the three leaf springs 9 which are rolling surfaces can be integrated to reduce the number of parts from three to one. The number of parts can be reduced, the assembly time can be shortened, and the manufacturing cost can be reduced.
[0058]
Moreover, since the ring-shaped connection part 20 is not the circular-arc-shaped connection part extended in the circumferential direction like the past, it can achieve compactization, without expanding the female shaft 2 to radial direction.
[0059]
Further, a small diameter portion 1 a formed at the end of the male shaft 1 passes through the ring-shaped connecting portion 20. Therefore, when the three leaf springs 9 are assembled, the small-diameter portion 1a at the end of the male shaft 1 is inserted into the ring-shaped connecting portion 20 so as to serve as a guide at the time of incorporation. The work can be facilitated, the assembling time can be shortened, and the manufacturing cost can be reduced.
[0060]
Further, the ring-shaped connecting portion 20 is disposed in the axial gap between the flat plate 13 of the stopper plate 10 and the annular surface 21 of the step. This axial clearance is, for example, about 0.3 to 2.0 mm.
[0061]
Due to the existence of the axial gap, the ring-shaped connecting portion 20 does not restrain the movement of the plate springs 9 even when the three plate springs 9 are deformed by torque input.
[0062]
Further, as shown in FIGS. 4 and 5, the cross-sectional shape of each leaf spring 9 is formed in a linear shape substantially parallel to the shape of the axial groove 3 of the male shaft 1. The peripheral part of the ring-shaped connection part 20 is connected. Both end portions of each leaf spring 9 are formed by folding back from the center side toward the outside.
[0063]
Further, a small diameter portion 1 a formed at the end of the male shaft 1 passes through the ring-shaped connecting portion 20. A radial gap is formed between the small diameter portion 1 a of the male shaft 1 and the ring-shaped connecting portion 20. The radial gap is, for example, 0.2 to 1.0 mm. Similar to the above-described axial gap, the ring-shaped connecting portion 20 does not restrain the movement of the leaf springs 9 when the three leaf springs 9 are deformed by torque input due to the existence of the radial gaps. It is like that.
[0064]
(Second Embodiment)
FIG. 7 is a cross-sectional view of the telescopic shaft for vehicle steering according to the second embodiment of the present invention.
[0065]
In the present embodiment, in the cross-sectional shape of each leaf spring 9, both end portions of each leaf spring 9 are folded back from the outside toward the inside. Other configurations and operations are the same as those in the above-described embodiment.
[0066]
(Third embodiment)
FIG. 8 is a cross-sectional view of the telescopic shaft for vehicle steering according to the third embodiment of the present invention.
[0067]
In the present embodiment, in the cross-sectional shape of each leaf spring 9, both end portions of each leaf spring 9 are folded back from the center side toward the outside, and a concave surface is formed on the inside surface. There are four contact points with the ball 7. Other configurations and operations are the same as those in the above-described embodiment.
[0068]
(Fourth embodiment)
FIG. 9 is a cross-sectional view of a telescopic shaft for vehicle steering according to a fourth embodiment of the present invention.
[0069]
In the present embodiment, a leaf spring member containing rubber or the like is used as the elastic body 9.
[0070]
In the cross-sectional shape of each leaf spring member 9, each leaf spring member 9 includes a base material 9a formed along the axial groove 3, an elastic portion 9b such as rubber provided inside the base material 9a, and an elastic portion 9b. And a plate portion 9c for rolling the ball 7.
[0071]
The base material 9a is configured so as not to exhibit elasticity by itself, and the leaf spring member 9 has a desired elasticity by forming an elastic portion 9b such as rubber with a sandwich structure of the base material 9a and the plate portion 9c. Has come to demonstrate.
[0072]
In addition, three peripheral edges of the ring-shaped connecting portion 20 are connected to the axial end portion of the base material 9a. Further, the plate portion 9c is formed in a planar shape. Other configurations and operations are the same as those in the above-described embodiment.
[0073]
(Fifth embodiment)
FIG. 10 is a cross-sectional view of the telescopic shaft for vehicle steering according to the fifth embodiment of the present invention.
[0074]
In the present embodiment, a leaf spring member containing rubber or the like is used as the elastic body 9.
[0075]
In the cross-sectional shape of each leaf spring member 9, each leaf spring member 9 includes a base material 9a formed along the axial groove 3, an elastic portion 9b such as rubber provided inside the base material 9a, and a base material 9a. And a plate portion 9c for rolling the ball 7 while sandwiching the elastic portion 9b therebetween.
[0076]
The base material 9a is configured so as not to exhibit elasticity by itself, and the leaf spring member 9 has a desired elasticity by forming an elastic portion 9b such as rubber with a sandwich structure of the base material 9a and the plate portion 9c. Has come to demonstrate.
[0077]
In addition, three peripheral edges of the ring-shaped connecting portion 20 are connected to the axial end portion of the base material 9a. Further, the plate portion 9c is formed in a planar shape. Other configurations and operations are the same as those in the above-described embodiment.
[0078]
(Sixth embodiment)
FIG. 11 is a cross-sectional view of a telescopic shaft for vehicle steering according to a sixth embodiment of the present invention.
[0079]
In the present embodiment, a leaf spring member containing rubber or the like is used as the elastic body 9.
[0080]
In the cross-sectional shape of each leaf spring member 9, each leaf spring member 9 includes a base material 9a formed along the axial groove 3, an elastic portion 9b such as rubber provided inside the base material 9a, and an elastic portion 9b. And a plate portion 9c for rolling the ball 7.
[0081]
The base material 9a is configured so as not to exhibit elasticity by itself, and the leaf spring member 9 has a desired structure by forming an elastic portion 9b such as rubber with a sandwich structure of the base material 9a and the plate portion 9c. It is designed to exhibit elasticity.
[0082]
In addition, three peripheral edges of the ring-shaped connecting portion 20 are connected to the axial end portion of the base material 9a. Further, the plate portion 9c is formed in an arc shape. Other configurations and operations are the same as those in the above-described embodiment.
[0083]
In addition, this invention is not limited to embodiment mentioned above, A various deformation | transformation is possible.
[0084]
【The invention's effect】
As described above, according to claim 1, at least two preload elastic bodies are connected by a connecting portion disposed at or near the end of the male shaft, and in the circumferential direction as in the prior art. Since it is not an arc-shaped connecting part that extends, the female shaft can be made compact without expanding the diameter in the radial direction, and each elastic body is integrally connected by the connecting part. The number of points can be reduced, the assembly time can be shortened, and the manufacturing cost can be reduced.
[0085]
According to claim 2, at least two preload elastic bodies are connected by a ring-shaped connecting portion disposed along an axial annular surface facing the axial direction of the male shaft, Since it is not an arc-shaped connecting portion extending in the circumferential direction, the female shaft can be made compact without expanding the diameter in the radial direction, and each elastic body is integrally connected by the connecting portion. Therefore, the number of parts can be reduced, the assembly time can be shortened, and the manufacturing cost can be reduced.
[0086]
Furthermore, according to claim 3, the small diameter part formed in the edge part of the male shaft has penetrated the ring-shaped connection part. Therefore, when assembling the elastic body for radial preload, the small diameter part at the end of the male shaft is inserted into the ring-shaped connecting part to serve as a guide for this assembling. Therefore, the assembly time can be shortened and the manufacturing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a telescopic shaft for vehicle steering according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line XX of FIG.
FIG. 3 is an enlarged vertical cross-sectional view in which a main part of FIG. 1 is enlarged.
4 is a cross-sectional view taken along line YY of FIG.
FIG. 5 is a perspective view of an elastic body (plate spring) connected by a connecting portion.
6 is a view taken in the direction of arrow A in FIG.
FIG. 7 is a cross-sectional view of a telescopic shaft for vehicle steering according to a second embodiment of the present invention.
FIG. 8 is a cross-sectional view of a telescopic shaft for vehicle steering according to a third embodiment of the present invention.
FIG. 9 is a cross-sectional view of a telescopic shaft for vehicle steering according to a fourth embodiment of the present invention.
FIG. 10 is a cross-sectional view of a telescopic shaft for vehicle steering according to a fifth embodiment of the present invention.
FIG. 11 is a cross-sectional view of a telescopic shaft for vehicle steering according to a sixth embodiment of the present invention.
FIG. 12 is a side view of a general automobile steering mechanism.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Male shaft 1a Small diameter part 1b Clamping part 2 Female shafts 3, 4 Axial direction groove (1st intervention part)
5,6 Axial groove (second intervention part)
7 Spherical body (ball, torque transmission member)
8 Columnar body (needle roller, torque transmission member)
9 Elastic body (leaf spring, leaf spring member)
9a Base material 9b Elastic portion 9c Plate portion 10 Stopper plate 11 Axial preload elastic body 12, 13 Flat plate 14, 15 Axially perpendicular surface 20 Ring-shaped connecting portion 21 Stepped annular surface (axial annular surface)

Claims (3)

In a telescopic shaft for vehicle steering, which is incorporated in a steering shaft of a vehicle, and a male shaft and a female shaft are fitted to each other so as not to be rotatable and slidable.
At least two sets of torque transmission members are disposed on at least two sets of interposing portions formed on the outer peripheral surface of the male shaft and the inner peripheral surface of the female shaft via at least two preload elastic bodies,
The telescopic shaft for vehicle steering, wherein the at least two preload elastic bodies are connected by a connecting portion disposed at or near an end of the male shaft. In a telescopic shaft for vehicle steering, which is incorporated in a steering shaft of a vehicle, and a male shaft and a female shaft are fitted to each other so as not to be rotatable and slidable.
At least two sets of torque transmission members are disposed on at least two sets of interposing portions formed on the outer peripheral surface of the male shaft and the inner peripheral surface of the female shaft via at least two preload elastic bodies,
The telescopic shaft for vehicle steering, wherein the at least two preload elastic bodies are connected by a ring-shaped connecting portion disposed along an axial annular surface facing the axial direction of the male shaft. . The telescopic shaft for vehicle steering according to claim 2, wherein a small-diameter portion formed at an end of the male shaft passes through the ring-shaped connecting portion.

Images