JPH0537052Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a steering shaft joint, and in particular, in a steering column of an automobile, the joint is placed between the steering shaft and the steering gear box, and is used to control the rotation of the steering wheel through the steering gear. Concerning what is communicated to the box.

BACKGROUND TECHNOLOGY In general, a steering shaft joint consists of an outer joint part made of a pipe body with an oval cross section, and an internal fitting part of a similar shape that is solid or hollow with an oval cross section. They are configured to be fitted in the axial direction, movable in the axial direction, and rotatable integrally in the circumferential direction. The axially movable configuration improves operational safety by preventing vibrations and noise generated by the engine or road surface conditions from being transmitted from the vehicle body to the steering wheel via the steering shaft. In order to improve this, it is widely practiced to interpose an elastic body such as rubber between the external fitting joint part and the internal fitting joint part.

Therefore, to explain a conventional steering shaft joint in which an elastic body is interposed, Fig. 5 is a side view showing the main parts of the steering column, in which 1 is the steering wheel, 2 is the steering column, and 3 is the external fitting joint. A steering shaft joint includes a portion 3a and an internal fitting portion 3b, 4 is a steering gear shaft, and 5 is a steering gear box. As shown in FIG. 6, the steering shaft joint 3 consists of an external fitting part 3a and an internal fitting part 3b inserted in the axial direction. It has a so-called oval cross section having flat parts 6, 6a and a pair of circular arc parts 7, 7a connecting both ends of these parts. 3c is a yoke portion that constitutes a universal joint, and 3d is a serration portion for connecting with the universal joint. The internal fitting portion 3b is provided with recesses 8, 8 facing each other in the axial direction, and an elastic body 9 such as a plate rubber is vulcanized and bonded to the recess 8. The elastic body 9 is the flat part 6 of the external fitting part 3a.
The inner fitting part 3b and the outer fitting part 3 are in contact with the inside of the
This prevents direct contact with a, thereby blocking the transmission of vibrations and noise.

According to this conventional example, when the rotational torque of the steering wheel is small, such as during normal driving, the inner fitting part 3b and the outer fitting part 3a are connected to each other through the elastic body 9 to resist deformation of the elastic body 9. The rotational torque is transmitted to the steering gear box 5 using. When the rotational torque increases, the internal fitting part 3b
flat parts 3f, 3f and flat part 6 of the external fitting part 3a
Direct contact with the inside of the shaft to transmit torque.

Problems to be Solved by the Invention However, according to the conventional steering shaft joint described above, the minute steering angle response during high-speed running is not necessarily good. The elastic body 9 has a constant length in the axial direction of the flat part 3f of the internal fitting part 3b, has a constant height, and is bonded to the recesses 8, 8 spaced at a predetermined interval. Since the structure is such that it contacts only the inside of the flat part 6 of the external fitting part 3a, the spring constant of the elastic body 9 is low, and a significant increase in deformation resistance cannot be expected. This is because the steering angle responsiveness is considered to be significantly reduced.

Therefore, in order to improve the response to small steering angles, the spring constant of the elastic body 9 may be set high, but if this is done, the vibration/noise isolation effect will be degraded. Furthermore, in order to improve the vibration/noise isolation effect, the spring constant may be lowered, but this results in a contradiction in that the response to small steering angles decreases.

Therefore, it is extremely difficult to set up a shaft joint with improved performance in both vibration and noise isolation and small steering angle response within a designated space without increasing the size. Currently, it is necessary to prioritize the performance of one or the other.

Therefore, the present invention provides a shaft joint that improves both vibration and noise isolation performance and minute steering angle response.

Means for Solving the Problems The steering shaft joint according to the present invention has at least one pair of flat parts in which an internal fitting part and an external fitting part face each other, and the flat part of the internal fitting part In the steering shaft joint formed by fixing an elastic body to the outer fitting part and fitting into the outer fitting part, a tapered recess with a roof-shaped cross section is formed in a part of the flat part of the inner fitting part in the longitudinal direction, and , characterized in that an annular elastic body is fixed to the tapered recess, the outer side of the concave portion being thicker than the inside thereof, and having an outer diameter slightly larger than the inner diameter of the external fitting portion. .

The annular elastic body has a concave portion or a corresponding concave portion formed in the axial direction of the internal fitting portion in the width center portion thereof, or a protrusion that presses against the inside of the circular arc portion of the external fitting portion. It is characterized by being done.

Effects According to the above configuration of the present invention, the annular elastic body has a thicker wall on the outside than on the inside of the tapered recess of the internal fitting joint, thereby improving the vibration/noise isolation effect and the response to minute steering angles. . Moreover, rotational torque exceeding a predetermined value is transmitted through direct contact between the flat parts of the internal fitting part and the external fitting part, and rotational torque below a predetermined value is transmitted by the annular elastic body in contact with the external fitting part. Moreover, since the annular elastic body surrounds the internal fitting part, it blocks the transmission of vibrations and noise generated in the vehicle body. Further, the concave portion and the recessed portion of the annular elastic body allow the deformation of the elastic body to escape, and the protrusion portion presses against the inside of the external fitting portion to improve its responsiveness.

Embodiments The present invention will be explained below based on illustrated embodiments.

1A and 1B respectively show an external fitting part 3a and an internal fitting part 3e. The external fitting part 3a has the same structure as the conventional structure, but the internal fitting part 3e has an elastic body 9, which will be described later. The part for fixing is different from that of the conventional method. That is, a chevron-shaped or roof-shaped tapered recess 3g is formed in the internal fitting portion 3e, leaving flat portions 3f, 3f at both ends. In FIG. 1A, the flat part 3f contacts the flat part 6 of the external fitting part 3a, and in the intermediate part and the proximal part of the internal fitting part 3e, and in FIG. 1B, respectively. are left behind, so that they can come into contact with each other when a rotational torque of a predetermined value or more is applied. Note that the internal fitting portion 3e may be a hollow body.

An annular elastic body 10 made of rubber or the like is fixed to the tapered recess 3g. The annular elastic body 10 is shown in FIG. 2A.
As shown in FIG. 2, the outside of the tapered recess 3g has a thicker wall than the inside, and its external dimensions are slightly larger than the inside cross-sectional shape of the external fitting joint 3a. It is inserted into the joint portion 3a and does not cause shear deflection. This annular elastic body 10 is fixed to the tapered recess 3g of the internal fitting part 3e by a method such as vulcanization adhesion.

Further, the annular elastic body 10 can be modified in various ways as shown in FIGS. 2B to 2F. In the figure, B shows a recess 13 formed in the flat part 11, C shows a recess 13 formed in the flat part 11, and a protrusion 14 formed in the arc part 12, and D shows a flat part 11 formed with a concave part 13. A concave portion 13 is formed in the circular arc portion 12, a protrusion portion 14 is formed in the circular arc portion 12, and a bulging portion 15 is formed in the connecting portion between the flat portion 11 and the circular arc portion 12. The recess 13 is provided to allow the protruding portions on both sides to escape when they are compressed. Projection 1
4 is provided to make close contact with the inner surface of the circular arc portion 7 of the external fitting joint portion 3a. Furthermore, FIG. 2E shows an example modified based on the annular elastic body 10 shown in A. In this example, there is no part corresponding to the flat part 11, and there is no part corresponding to the flat part 11, and there is a part inward from both circular arc parts 12, 12 toward the width center. A recessed portion 16 is formed in the axial direction, and this recessed portion 16 allows the corner portion 17 to escape during compression. F in FIG. 2 has a protrusion 14 formed on the arcuate portion 12 together with the recess 16 of E.

As an example of fixing the annular elastic body 10 to the internal fitting part 3e, FIG. 3 shows various modifications. This tapered recess 3g is formed in two places in the axial direction, facing each other in the direction.
The annular elastic body 10 is fixed to A as a series with a predetermined length, B divided into three parts, or C having a groove 18 dividing it into three parts. Further, in D of the figure, tapered recesses 3g are formed to face each other in the diametrical direction and axial direction of the internal fitting part 3e, and annular elastic bodies 10, 10 are respectively formed in these tapered recesses 3g, 3g. It is fixed.

FIGS. 4A and 4B show a cross-sectional structure in which the external fitting part 3a and the internal fitting part 3e are fitted together. In the illustration, the tapered recess 3g of the internal fitting part 3e is arranged to obliquely intersect the inner circumferential surface of the external fitting part 3a at a predetermined angle, so that the internal fitting part 3e is rotated with a rotational torque of a predetermined value or more. Then, the flat part 3f becomes the external fitting part 3a.
The torque is transmitted by making line contact with the flat portion 6 at. Therefore, the durability of the rubber is improved. On the other hand, when the rotational torque is below a predetermined value, the rotational torque is transmitted through the annular elastic body 10 without surface contact between the flat portion 3f and the flat portion 6. Therefore, the annular elastic body 1
0 is thicker on the outside than on the inside of the tapered recess 3g of the internal fitting portion 3e, so the vibration and noise isolation performance is improved. Therefore, even if the small steering angle response is improved by using an elastic body with a high spring constant, it is possible to freely set the amount of elastic body necessary for blocking vibration and noise, and the small steering angle response is improved. vibration·
A shaft joint that also has noise isolation can be obtained. Further, when a rotational torque acts on the internal fitting part 3e, the annular elastic body 10 is moved around the internal fitting part 3e by a slight rotational movement about the axis of the internal fitting part 3e.
The tapered recess 13 is twisted and compressed between the outer fitting part 3a and the outer fitting part 3a, but since both sides of the tapered recess 13 are made thick and an elastic body is fixed around the entire circumference of the inner fitting part 3e, the inner fitting part 3a is twisted and compressed. The bending rigidity due to the second moment of inertia between the fitting joint part 3e and the external fitting joint part 3a is improved, and as a result, the torsional rigidity is improved.

Effects of the invention According to the invention described above, the internal fitting part has an annular elastic body inscribed in the external fitting part, and the annular elastic body is formed in the tapered recess provided in the internal fitting part. Since the outer wall is thicker than the inner wall, it is possible to improve minute steering angle response and reduce vibration by selecting the amount, hardness, or shape of the annular elastic body without increasing the size within a given space. A shaft joint that also has noise isolation can be obtained.

In addition, when the torque is below a predetermined value, the internal fitting joint and the external fitting joint are transmitted through the annular elastic body, but when the torque is above a predetermined value, the flat parts of the internal fitting joint and the external fitting joint are transmitted. Since the information is transmitted through direct contact, the annular elastic body is not extremely compressed and its durability is improved.

Furthermore, since the annular elastic body is fixed around the entire circumference of the internal fitting part, the bending rigidity due to the second moment of inertia between the internal fitting part and the external fitting part is also improved, and therefore the torsional rigidity is improved. , etc.

[Brief explanation of the drawing]

1A and 1B are perspective views of essential parts showing an embodiment of the present invention, FIGS. 2A to 2F are sectional views showing an annular body made of an elastic body and its modified form, and FIGS.
Figures A to D are longitudinal cross-sectional views showing examples of fixation between the annular body and the internal fitting part, Figures 4A and B are cross-sectional views of the steering shaft joint, and Figure 5 is an overall side view of the steering device. , FIG. 6 is a perspective view of essential parts of a conventional example. 3... Steering shaft joint, 3a... External fitting joint part, 3e... Internal fitting joint part, 3f... Flat part, 3
g... Tapered recess, 10... Annular elastic body, 1
1... Flat part, 12... Arc part, 13... Concave part,
14... protrusion, 15... bulge, 16... recess.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) The internal fitting joint part and the external fitting joint part have at least a pair of opposing flat parts, and an elastic body is fixed to the flat part of the internal fitting joint part. In the steering shaft joint fitted to the external fitting part,
A tapered recess with a roof-shaped cross section is formed in a part of the flat part of the internal fitting part in the longitudinal direction, and the tapered recess has a wall thickness larger on the outside than on the inside, and A shaft joint for steering, characterized in that it is formed by fixing an annular elastic body having an outer diameter slightly larger than the inner diameter of a fitting joint part. (2) The steering shaft joint according to claim 1, wherein the annular elastic body has a concave portion or a corresponding concave portion formed in the axial direction of the internal joint portion at the center of its width. (3) The steering shaft joint according to claim 1, wherein the annular elastic body is formed with a protrusion that presses against the inside of the circular arc portion of the external fitting joint.