JPH034031A - Elastic joint for steering shaft - Google Patents

Abstract

PURPOSE:To sufficiently contract the full length so as to improve safety at the time of collision by serration-engaging the end part of a shaft and forming a through hole, in which this shaft can be inserted, in a part opposed to an end surface of the shaft in the central part of a member for constituting the first and second connecting means. CONSTITUTION:A serration part 23 is formed in the end part of a shaft 22, connected to the input shaft or the like of a steering gear, and engaged with a serration hole 25 formed in the central part of a flange 24. A coupling member 3 is connected by the first bolts 6, 6 inserted through a through hole 9 formed in a position of both end parts 2 of a flange 24, first retainer plate 8 and the first nuts 7, 7. The second fork part 29, provided on the inner end side of a yoke 27, is connected by the second bolt 13 inserted into a through hole formed in a position of both end parts of this fork part 29, second retainer plate 15 and the second nut 14.

Description

[Detailed Description of the Invention] (Industrial Application Field) The elastic joint for a steering shaft according to the present invention can be attached to the end of a steering shaft of an automobile.
This is to prevent vibrations applied to the steering wheel from being transmitted to the steering wheel, and is intended to secure a larger amount of contraction, especially in the event of a car collision, to ensure driver safety.

(Prior Art) A steering device for an automobile is configured to transmit the movement of the steering wheel to a steering gear via a steering shaft, and to impart a steering angle to the steered wheels (numerically, the front wheels). .

Such a steering device is -8 in number! Since it is configured with an a-mechanical transmission mechanism, if left as is, vibrations applied to the steering wheel due to driving on rough roads, etc., will be transmitted to the steering wheel via the steering gear and steering shaft.

In this way, if vibrations caused by driving on rough roads are transmitted to the steering wheel, it will cause discomfort to the driver, so an elastic joint is provided at the end of the steering shaft to absorb this vibration. This prevents vibrations from the steering wheel from being transmitted directly to the steering wheel.

As such an elastic joint for a steering shaft, a structure such as that disclosed in, for example, Japanese Utility Model Application Publication No. 191528/1983 has been known.

This conventional elastic joint for a steering shaft is constructed as shown in FIG. 4 by combining parts shown in FIG. 3.

3 and 4, 1 is a flange fixed to the end of a shaft 2 leading to a steering gear. Also, 3
is a coupling member made of an elastic material such as rubber, and the elastic joint is configured to absorb vibrations by the elasticity of the coupling member 3. Reference numeral 4 denotes a yoke that faces the flange 1 via the coupling member 3, and connects the yoke 4 and the end of a steering shaft (not shown) with a universal joint 5 (representing an embodiment of the present invention). (See Figures 1 and 2).

The flange 1 and the coupling member 3 have a first bolt 6.6, a first nut 7.7 at two diametrically opposite positions, and an arcuate notch at two diametrically opposite positions. They are coupled by a first coupling means constituted by a first restraining plate edge formed in an occluded circular shape.

That is, through holes 9 are formed at two positions on both ends of the flange 1.
．． The first bolt 6.6 inserted through the bolt 9 is inserted into four through holes 10.11 formed at equal intervals in the coupling member 3
A pair of through holes 10.1 located at opposite positions in the diametrical direction.
0 and through holes 12.12 formed at both ends of the first restraining plate 8, and then a first nut 7.7 is screwed into the tip thereof and tightened.

On the other hand, the yoke 4 and the coupling member 3 are connected at two diametrically opposite positions, with second bolts 13, 13,
They are coupled by a second coupling means constituted by a second nut 14.14 and a second press plate 15 formed in the same oval shape as the first press plate 8. That is,
Both ends 2 of the base end of yoke 4! ! A through hole formed at the i position!
The second bolt 13.13 that has been inserted through the second bolt 13.13 passes through the remaining through hole 11.11 of the four through holes 10.11 formed in the coupling member 3, and is inserted into the second holding plate. After passing through holes 17.17 formed at both ends of the nut 15, a second nut 14.14 is screwed onto the tip thereof and tightened.

As a result, the flange 1 and yoke 4 fixed to the end of the shaft 2
As shown in FIG. 4, they are connected via a coupling member 3 made of an elastic material. In this state, by operating the steering wheel (not shown), the steering shaft (also not shown) is rotated, and the universal joint 5
(Figs. 1 and 2), when the yoke 4 is rotated in the t return direction, this rotation is transmitted to the flange 1 via the coupling member 3, and the shaft 2 to which the flange 1 is fixed rotates in the torsional direction. do.

Since the coupling member 3 is made of an elastic material such as rubber, when the amount of displacement (rotation angle) of the yoke 4 is small, the coupling member 3 absorbs this amount of displacement by elastically deforming. The rotational motion is prevented from being transmitted to the flange 1, but the amount of displacement absorbed becomes the play normally provided in the steering device. When vibration is transmitted from the steering wheel to the shaft 2, the coupling member 3 absorbs this vibration and prevents the yoke 4 connected to the steering shaft from vibrating.

Note that the first sleeve 1 into which the first bolt 6.6 is inserted
8.18 is a second sleeve 20.20 in which a second bolt 13.13 is inserted into a second notch 19.19 formed in the second restraining plate 15; Each sleeve 18.20 engages with a first notch 21.21 formed in each notch 19.21, and the displacement of the flange 1 and yoke 4 in the torsional direction Since this is possible only within the range in which it can move inside, there is no possibility that the amount of elastic deformation of the coupling member 3 will become excessive and the coupling member 3 will be damaged.

(Problems to be Solved by the Invention) However, the conventional elastic joint for a steering shaft that is constructed and operates as described above has inherent problems as described below.

In other words, even if the front of the car is crushed in a collision,
To prevent the rear end of the steering shaft from moving backwards (into the vehicle interior), and to prevent the driver's body from violently colliding with the steering wheel installed at the rear end of the steering shaft. (In order to reduce the risk of secondary collisions), the parts that make up the steering system are made to have a structure that can contract in length when an impact force is applied, but the conventional elastic joint for steering described above In this case, the length cannot be made freely retractable, or even if it is retractable, only a small amount of shrinkage can be secured.

Even if the elastic joint is made to have a collapsible structure, it is possible to ensure a certain level of safety by making the steering shaft collapsible, a so-called collapsible steering shaft, but a higher degree of safety can be ensured. (to save the lives of passengers in the event of a high-speed collision), it is preferable to secure a larger amount of contraction.

For this reason, conventionally, in order to ensure a high degree of safety, it was necessary to use retractable joints (not elastic joints) at the connection between the end of the steering shaft and other parts such as the steering gear. However, when joints other than elastic joints are used in this way, it is not possible to sufficiently prevent the vibrations of the steering wheels from being transmitted to the steering shaft, and when driving on rough roads, the driver It is inevitable that it will cause discomfort.

The elastic joint for a steering shaft of the present invention eliminates the above-mentioned disadvantages.

(Means for Solving the Problem) The elastic joint for a steering shaft of the present invention is provided at the end of a shaft, similar to the conventional elastic joint for a steering shaft, and transmits rotational force between the shaft and the shaft. a flange that is freely adjustable, a coupling member made of an elastic material, a yoke that faces the flange via the coupling member, and a first connection in which the flange and the coupling member are coupled at a plurality of locations. and a second coupling means that couples the yoke and the coupling member at a plurality of points different from the first coupling means.

Further, in the elastic joint for a steering shaft of the present invention, a serration hole is formed in the center of the flange, and the end of the shaft is engaged with the serration hole, so that the center portion of the coupling member has a serration hole. and a through hole through which the shaft can be freely inserted is formed in a portion facing the end surface of the shaft and in a central portion of the member constituting the first and second coupling means and facing the end surface of the shaft. are doing.

(Function) The elastic joint for a steering shaft of the present invention configured as described above has the effect of transmitting the rotational motion in the steering direction from the steering shaft to other members such as the steering gear, and the effect of transmitting the rotational movement of the steering wheel. The effect of preventing vibrations from being transmitted to the steering shaft is similar to that of the conventional elastic joint for a steering shaft described above.

However, in the case of the elastic joint for a steering shaft of the present invention, when an axial impact force (compressive force) is applied due to a collision, the overall length of the elastic joint is shortened to absorb this impact force.

That is, m'! in the compression direction at the time of collision! When i force is applied,
The serration hole formed at the center of the flange and the serration section formed at the end of the shaft slide against each other, thereby causing the shaft to move rearward. This movement causes the axis to
It passes through a through hole formed in the center of the member constituting the coupling member and the first and second coupling means.

In this way, as a result of the shaft passing through the hole in the center of each member,
It is possible to secure a sufficient amount of displacement 1 of the shaft, that is, the amount of contraction of the elastic joint, and it is possible to suppress the ifi impact force applied to the driver at the time of a collision.

(Example) Next, the present invention will be explained in more detail while explaining the illustrated embodiment.

Figures 1 and 2 show an embodiment of the elastic joint for a steering shaft according to the present invention, with Figure 1 showing a normal state and Figure 2 showing a partial cross-sectional view of a state in which the overall length has been shortened due to an impact. It is.

A serration portion 23 is formed at the end of the shaft 22 that is connected to the input @shade of the steering gear via a joint (not shown). engaged.

As a result, the rotational force in the torsional direction can be freely transmitted between the shaft 22 and the flange 24.

That is, the inner side of the cylindrical part 30 formed at the center of the flange 24 is made into a serration hole 25, formed at the end of @22, and the serration part 23 is engaged with both members 24.2.
Rotational force in the torsional direction can be freely transmitted between the two. Also, a space 3 between the recess 31 formed on the outer circumferential surface of the intermediate portion of the serration portion 23 and the inner circumferential surface of the cylindrical portion 30.
3 is filled with synthetic resin through a small hole 32 formed in this cylindrical portion 30, and this synthetic resin allows the shaft 22 to
and the flange 24 are joined together without rattling. However, the synthetic resin in this space 33 will easily break if an impact force is applied to the glaze 22 in the axial direction, and the flange 2
The displacement of the shaft 22 with respect to 4 is allowed.

The coupling member 3 is made of an elastic material such as rubber.
A first bolt 6.6 is inserted into the flange 24 through the through hole 9 formed at two positions on both ends of the flange 24, as in the case of the conventional elastic joint for a steering shaft described above. It is connected by a retaining plate 8 and a first nut 7.7. At the middle of the first bolt 6.6,
A sleeve 26 is fitted onto the portion located between the flange 24 and the first restraining plate 8, and furthermore, a half portion of this sleeve 26 is located between the flange 24 and the coupling member 3! , the first sleeve 18 is fitted over the two portions.

On the other hand, the flange) is connected via the coupling member 3.
The yoke 27 facing 24 has second and second bifurcated parts 28 and 29 formed at both ends, and the outer end side of the elastic joint (@1
A universal joint 5 is provided at the first bifurcated portion 28 (on the right end side in Figure 2) to freely connect the yoke 27 and the end of the steering shaft.

Then, the second bifurcated portion 29 provided on the inner end side of the yoke 27 is connected to the coupling member 3, as in the case of the conventional elastic joint for a steering shaft described above.
The second forked portion 29 is connected by a second bolt 13 inserted through holes formed at two positions on both ends thereof, a second restraining plate 15, and a second nut 14.

Further, the central portion jζ of the coupling member 3 has a through hole 34.
Form and! The end of the medium-heat cylindrical portion 30 of the flange 24 is inserted into this through hole 34.

Furthermore, the center part of the first holding plate 8 for coupling the flange 24 and the coupling member 3, the center part of the second holding plate 15 for coupling the yoke 27 and the coupling member 3,
Through holes 35, 36, and 37 are formed in the center of the yoke 27, respectively, through which the shafts 22 can be inserted.
5.27 is 8 to the rear of the shaft 22 (to the right in Figures 1 and 2)
I try not to obstruct movement. However, the cylindrical portion 30 with the @22 inserted therein is inserted into the through hole 36 at the center of the second holding plate 15 from the normal state (the state shown in FIG. 1).

The elastic joint for a steering shaft of the present invention configured as described above allows the action of transmitting rotational force in the torsional direction from the steering shaft to other members such as the steering gear, and the vibration of the steering wheel to the steering shaft. The effect of preventing the force from being transmitted is the same as that of the conventional elastic joint for a steering shaft described above.

That is, when the yoke 27 is rotated in the return direction via the universal joint 5, this rotation is transmitted to the flange 24 via the coupling member 3, and the shaft 22 engaged with the flange 24 through serrations is rotated in the weeping direction. Rotate.

Since the coupling member 3 is made of an elastic material such as rubber, when vibration is transmitted from the steering wheel to the shaft 22, the coupling member 3 absorbs this vibration and the universal joint 5
Yoke 27 connected to the steering shaft via
to prevent vibration. As a result, the steering wheel provided at the end of the steering shaft does not vibrate and cause discomfort to the driver.

When the amount of displacement of the yoke 27 is small, the coupling member 3 is elastically deformed to absorb this amount of displacement as play, and the displacement in the torsional direction between the flange 24 and the yoke 27 is It is also possible to prevent damage to the coupling member 3 by the engagement between the sleeve 18.20 and the notch 19.21 formed in the first and second restraining plates 8.15. This is similar to the elastic joint for the steering shaft.

However, in the case of the elastic joint for a steering shaft of the present invention, due to a collision, the axial direction (horizontal direction in Figs. 1 and 2)
When an impact force of 1 is applied, the shaft 22 is displaced relative to the flange 24, thereby reducing the overall length of the elastic joint to absorb this impact force.

That is, in order to connect the cylindrical portion 30 at the center of the flange 24 and the shaft 22 when an impact force is applied in the compression direction (rightward in FIGS. 1 and 2) at the time of a collision, the synthetic material filled in the space 33 The resin is broken, and the serrations 23 formed at the end of the shaft 22 slide inside the serration holes 25 formed by the inner peripheral surface of the cylindrical portion 30 at the center of the flange 24 .

As a result, the shaft 22 moves rearward (to the right in FIGS. 1 and 2). During this movement, the shaft 22 is moved to the inside of the through hole 34 formed in the center of the coupling member 3, to the first holding plate 8.
The yoke 27 passes through the through hole 35 formed in the center of the yoke 27 and the through hole 37 formed in the center of the yoke 27 in order, and is displaced to the state shown in FIG.

As a result of the shaft 22 being displaced while passing through the through hole 34.35.37 formed in the center of each member 3.8.27, the amount of displacement of the shaft 22, that is, the amount of contraction of the elastic joint can be sufficiently controlled. This makes it possible to keep the impact force applied to the driver in the event of a collision to a small level.

Incidentally, the cylindrical portion 30 formed at the center of the flange 24 and provided with the serration holes 25 inside can also be formed toward the outside of the elastic joint (toward the left in FIG. 1). In this case, the through holes 34 and 36 provided in the second holding plate 15 and the coupling member 3 are connected to the serration portion 23 of the shaft 22.
It is fine as long as it is large enough to pass through. Further, the cylindrical portion 30 may be formed separately from the flange 24 and fixed together in combination.

(Effects of the Invention) Since the elastic joint for a steering shaft of the present invention is constructed and operates as described above, the entire length can be sufficiently retracted while maintaining the performance of preventing transmission of vibration from the steering wheel to the steering wheel. This makes it possible to ensure a high level of safety in the event of a collision.

[Brief explanation of drawings]

Figures 1 and 2 show an embodiment of the elastic joint for a steering shaft of the present invention, with Figure 1 being a normal state and Figure 2 being a partial cross-sectional view of the state in which the overall length has been shortened due to impact. , 3 and 4 show a conventional elastic joint for a steering shaft, with FIG. 3 being an exploded perspective view and FIG. 4 being a perspective view showing an assembled state. 1: Flange, 2: Shaft, 3: Coupling member, 4: Yoke, 5: Universal joint, 6: First bolt, 7: First nut, 8: First holding plate, 9.10.11 .12: Through hole, 13: Second bolt, 14: Second nut, 15: Second holding plate, 16.17: Through hole, 18: First sleeve, 19; Second notch, 20: second sleeve, 21
: first notch, 22: shaft, 23: serration part,
24: flange, 25: serration hole, 26: sleeve, 27: yoke, 28: first bifurcated portion, 2 second bifurcated portion, 30: cylindrical portion, 31: recessed portion, : small hole, space, 34. 35, 6, through hole. Patent applicant NSK Ltd. (one idiot) Figure Figure 2 +8

Claims (2)

[Claims] (1) A flange provided at the end of the shaft and capable of freely transmitting rotational force between the shaft and the shaft, a coupling member made of an elastic material, and a flange facing the flange through the coupling member. A first coupling means that couples the yoke, the flange, and the coupling member at a plurality of points; and a second coupling means that couples the yoke and the coupling member at a plurality of locations different from the first coupling means. In the elastic joint for a steering shaft comprising a coupling means, a serration hole is formed in the center of the flange, and an end of the shaft is engaged with the serration hole,
The shaft is attached to a central portion of the coupling member facing the end surface of the shaft, and a central portion of the member constituting the first and second coupling means facing the end surface of the shaft. An elastic joint for a steering shaft characterized by forming a through hole that can be inserted freely. (2) The steering according to claim 1, further comprising a joint between the shaft and the flange that breaks when an impact force is applied in the axial direction and allows the shaft to freely slide with respect to the flange. Elastic joint for shaft.