JPH0740840A - Steering damper - Google Patents

Abstract

PURPOSE:To improve both of vibration absorptivity and steering stability by making constitution wherein a second elasticity part, having rigidity higher than that in a first elasticity part and elastically deformed in a second region where relative rotation quantity exceeds a first set value to reach a second set value, is provided on the same cross section neary straight-going to an axis. CONSTITUTION:The cylindrical part 13b of an elastic body 13 is elastically deformed in a broader range compared with the plane part 3a of the elastic body 13 to be functioned so as to have high rigidity. In a first region where the relative rotation quantity of a tube shaft body 11 and a shaft body 12 reach a first set value theta1, a low-rigidity damper function is displayed to obtain good vibration absorptivity to appropriately perform fluttering measures by elastically deforming locally the plane part 13a of the elastic body 13. In a second region where the relative rotation quantity of the tube shaft body 11 and the shaft body 12 exceeds the first set value theta1 to reach a second set value theta2, appropriate rigidity and vibration absorptivity can be obtained to improve both of steering stability and vibration absorptivity by elastically deforming the cylindrical part 13b of the elastic body 13 in a broad range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering damper installed in a torque transmission system for connecting a steering wheel and a gear box in a steering device for an automobile.

[0002]

2. Description of the Related Art A steering damper of this type is disclosed, for example, in Japanese Utility Model Laid-Open No. 63-18628. The steering damper of the publication has a configuration in which an elastic body is interposed between a tube shaft body having a non-circular cross section and a shaft body having a non-circular cross section inserted into the tube shaft body in a relatively rotatable manner. The elastic body fixing portion is provided, and the flat surface portion that directly contacts the tube shaft body with a predetermined relative rotation amount is provided.

[0003]

In the above-mentioned conventional steering damper, the relative rotation amount (twisting angle) between the pipe shaft body and the shaft body becomes a predetermined value, and the flat portion provided on the shaft body serves as the pipe shaft body. After direct contact, the damper function of the elastic body is not exerted and the vibration absorption is poor. By the way, when the above-mentioned predetermined value is set to a large value, the damper function by the elastic body is exerted even at a high torsion angle to improve the vibration absorption, but the rotation of the steering wheel is not accurately transmitted to the gear box. When the predetermined value is set to a small value, on the other hand, the maneuverability is improved but the vibration absorbing property is deteriorated. The present invention has been made to address the above-described problems, and an object thereof is to improve both vibration absorption and steering stability.

[0004]

In order to achieve the above object, in the present invention, a pipe shaft having a non-circular cross section and a shaft having a non-circular cross section inserted into the pipe shaft so as to be rotatable relative to each other by a predetermined amount. It is configured by interposing an elastic body between the bodies,
In a steering damper interposed in a torque transmission system that connects a steering wheel and a gear box, the elastic body is provided in a first region until a relative rotation amount of the tube shaft body and the shaft body reaches at least a first set value. A first elastic portion that elastically deforms, and a second elastic portion that has higher rigidity than the first elastic portion and that elastically deforms in a second region until the relative rotation amount exceeds the first set value and reaches the second set value. The structure is provided in the same cross section that is substantially orthogonal to the axis.

Further, in the present invention, in the above steering damper, the space formed between the pipe shaft body and the shaft body for accommodating the elastic body is a single arc-shaped portion and both ends thereof. A first elastic portion is arranged in the connecting portion, and the second elastic portion is formed in the arc-shaped portion.
The elastic portion is arranged. In the above steering damper, a pair of cavities in which the space formed between the tube shaft body and the shaft body for accommodating the elastic body are opposed to each other, and a pair of connecting the respective end portions thereof. It is characterized in that the first elastic portion and the second elastic portion are arranged in series in the torque transmission direction at both end portions of each connecting portion. Further, in the steering damper described above, a pair of first accommodating portions, in which a space formed between the tube shaft body and the shaft body is opposed to each other for accommodating the elastic body, are connected to respective end portions thereof. It consists of a pair of second accommodating parts, each first
It is characterized in that the first elastic portion that is mainly sheared and deformed is disposed in the storage portion, and the second elastic portion that is mainly compressed and deformed is disposed in each second storage portion.

[0006]

In the steering damper according to the present invention, the first elastic portion is elastically deformed in the first region until the relative rotation amount between the pipe shaft body and the shaft body reaches at least the first set value. The second elastic portion elastically deforms in the second region until the relative amount of rotation of the shaft body exceeds the first set value and reaches the second set value. By the way, since the second elastic portion has higher rigidity than the first elastic portion, a damper function of low rigidity is exerted in the first region until the relative rotation amount between the pipe shaft body and the shaft body reaches the first set value. Good vibration absorption is obtained, countermeasures against flutter are taken accurately, and in the second region until the relative rotation amount of the pipe shaft body and the shaft body exceeds the first set value and reaches the second set value. Proper rigidity and vibration absorption are obtained, and both maneuverability and vibration absorption are improved. Further, in the steering damper according to the present invention, since the elastic body interposed between the pipe shaft body and the shaft body has the above-mentioned first elastic portion and the second elastic portion in the same cross section substantially orthogonal to the axis, The steering damper can be made compact in the axial direction.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a steering damper 1 according to the present invention.
1 shows a steering device of an automobile adopting 0. In this steering device, a torque transmission system connecting a steering wheel 21 and a gear box (not shown), that is, a steering main shaft integrally having the steering wheel 21 at the upper end. An intermediate shaft, which is connected to 22 via a universal joint 23 so as to be able to transmit torque and is also connected to a gear box (not shown) so as to be able to transmit torque, is configured as the steering damper 10.

As shown in FIGS. 2 and 3, the steering damper 10 has a pipe shaft 11 having a non-circular cross section and a non-circular cross section inserted into the pipe shaft 11 so as to be rotatable relative to each other by a predetermined amount. The shaft body 12 and the shaft body 1 previously fitted to the shaft body 12
2 is fitted into the pipe shaft body 11 together with the pipe shaft body 11 and the shaft body 1.
It is composed of a rubber elastic body 13 interposed between the two. The tube shaft body 11 is composed of a tubular portion 11a having a non-circular cross section in which a cylindrical portion is flat, and a yoke 11b integrally formed at one end of the tubular portion 11a.

The shaft body 12 has a non-circular cross section in which a part of a cylindrical shape is flat, and a mounting portion 12a to which the elastic body 13 is mounted.
And stopper portions 12b and 12c formed on both sides of the mounting portion 12a in a shape similar to the mounting portion 12a and slightly larger,
The serration portion 12d is formed continuously with the mounting portion 12c and is connected to the universal joint 24 on the gear box side, and includes the mounting portion 12a and the tubular portion 11 of the pipe shaft body 11.
A space for accommodating the elastic body 13, that is, a space composed of an arcuate portion having a single cross-sectional shape and a connecting portion for connecting both ends thereof is formed between a. The elastic body 13 is composed of a flat surface portion (having a linear cross section) 13a and a cylindrical portion (having a circular cross section) 13b that are integrally molded and are arranged in the same cross section that is substantially orthogonal to the axis. ,
As shown in FIGS. 3 and 4 (A), the pipe shaft body 11 and the shaft body 12 are coaxial with each other with no space between the mounting portion 12a of the shaft body 12 and the tubular portion 11a of the pipe shaft body 11. Connected to.

In this embodiment constructed as described above, the relative rotation amount (twisting angle) between the pipe shaft body 11 and the shaft body 12 reaches from the zero to the first set value θ1 (the stopper portion 12b of the shaft body 12). In the first region until the flat corner portion directly contacts the tube shaft body 11, the flat surface portion 13a of the elastic body 13 is elastically deformed as shown in FIGS. The relative rotation amount of the body 11 and the shaft body 12 exceeds the first set value θ1 and reaches the second set value θ2 (the stopper portion 1 of the shaft body 12
The cylindrical portion 13b of the elastic body 13 elastically deforms as shown in FIGS. 4B and 4C in the second region until the cylindrical portion 2b directly contacts the tube shaft body 11. 4 illustrates the case where the shaft body 12 rotates clockwise with respect to the pipe shaft body 11, but the same operation is performed when the shaft body 12 rotates counterclockwise with respect to the pipe shaft body 11. Is obtained.

By the way, the cylindrical portion 13b of the elastic body 13 elastically deforms in a wider area than the flat surface portion 13a of the elastic body 13 and functions to have high rigidity, so that the three-step bending characteristic shown in FIG. In the first region until the relative rotation amount between the pipe shaft body 11 and the shaft body 12 reaches the first set value θ1, the flat surface portion 13a of the elastic body 13 is locally elastically deformed to have low rigidity. The damper function is exerted, good vibration absorption is obtained, countermeasures against flutter are properly taken, and the relative rotation amount of the pipe shaft body 11 and the shaft body 12 exceeds the first set value θ1 and the second set value θ2. In the second region until reaching, the cylindrical portion 13b of the elastic body 13 is elastically deformed over a wide range, so that appropriate rigidity and vibration absorption are obtained, and both maneuverability and vibration absorption are improved. Further, in the above-described second region, the flat corner portion of the stopper portion 12b of the shaft body 12 is in direct contact with the tube shaft body 11, and relative rotation hardly occurs at the same portion. 13a is not excessively compressed and deformed, and in the third region in which the relative rotation amount of the tube shaft body 11 and the shaft body 12 exceeds the second set value θ2,
The flat corner portion of the stopper portion 12b of the shaft body 12 is the pipe shaft body 11.
And the stopper portion 1 of the shaft body 12
Since the cylindrical portion of 2b is in direct contact with the tube shaft body 11 and relative rotation does not occur at the same portion, the flat surface portion 1 of the elastic body 13
Both 3a and the cylindrical portion 13b are not excessively compressed and deformed. Therefore, the durability of the elastic body 13 is improved.

In the above embodiment, the elastic member 13 made of rubber is formed by integrally forming the flat surface portion 13a and the cylindrical portion 13b.
Although the present invention has been implemented by adopting the above, as shown in FIGS. 6 and 7, the rubber-made flat plate elastic body 13A and the attachment portion 12a, which are attached to the flat surface of the attachment portion 12a of the shaft body 12, are attached. It is also possible to implement the present invention by adopting a curved elastic body 13B made of rubber that is attached to the cylindrical surface. Also in this case, as is clear from FIGS. 7A, 7B, and 7C, the same effect as the above embodiment can be obtained, but in this case, as compared with the flat plate elastic body 13A. It is also possible to manufacture the curved elastic body 13B with a highly rigid material, and it is possible to obtain a steep characteristic in the characteristic of the second region shown in FIG.

FIGS. 8 and 9 show another embodiment of the present invention. In the steering damper 100 of this embodiment, the non-circular cross section of the pipe shaft body 111 and the shaft body 112 is different from that of the above embodiment. A pair of arc-shaped cavities (the shape of which is not limited to an arc shape and may be linear) in which the space portions formed between the two are opposed to each other, and each of these end portions are respectively formed. It has a shape consisting of a pair of connecting portions for connection. In addition, the tube shaft body 111 and the shaft body 112 are attached to the flat surfaces of the mounting portion 112a of the shaft body 112, respectively.
Flat cavities 113a that extend in the axial direction and open are formed on both sides (portions that are largely elastically deformed) of the rubber-made flat plate elastic body 113 that is interposed without a gap therebetween, and the presence of these cavities 113a causes the vicinity of the cavities to occur. It functions as if it has low rigidity. Therefore, the tube shaft body 111 and the shaft body 112
9 in the first region from when the relative rotation amount of 0 reaches the first set value θ1 (in this state, the flat corner portion of the stopper portion 112b of the shaft body 112 is not in direct contact with the pipe shaft body 111). As shown in (A) and (B), the elastic body 113 is elastically deformed mainly in the vicinity of the cavity 113a, and the relative rotation amount of the tube shaft body 111 and the shaft body 112 is the first set value θ.
9 (B) and 9 (C) in the second region until the second set value θ2 is exceeded by 1 (the flat corner portion of the stopper portion 112b of the shaft body 112 directly contacts the pipe shaft body 111). As shown, the elastic body 113 having high rigidity is elastically deformed in the state where the cavity 113a is almost disappeared. Therefore, also in this embodiment, the characteristics shown in FIG. 5 similar to those of the above-mentioned embodiment can be obtained.

In the above-described embodiment shown in FIGS. 8 and 9, the present invention is embodied by employing the rubber flat plate elastic body 113 having the cavity 113a and elastically deforming in the first region and the second region. However, as shown in FIGS. 10 and 11, the thin rubber elastic body 11 made of rubber is attached to the flat surface of the mounting portion 112a of the shaft body 112 and compressively deforms in the second region.
3A, a rubber elastic body 113B attached to the cylindrical surface of the mounting portion 112a of the shaft body 112 and the cylindrical inner peripheral surface of the cylindrical portion 111a of the pipe shaft body 111, respectively, and shear-deformed in the first region and the second region. It is also possible to implement the present invention by adopting. In this case, in the first region, the elastic body 113
Only B is sheared and the elastic body 11 in the second region
As 3B undergoes shear deformation, the elastic body 113A undergoes compressive deformation, and the characteristics shown in FIG. 5 are obtained as in the above-described respective embodiments.

In each of the above-mentioned embodiments, the one that is deformed in the first region and the one that is deformed in the second region of the elastic body interposed between the tube shaft body and the shaft body have the same cross section substantially orthogonal to the axis. Since the steering damper is arranged, the steering damper can be configured to be compact in the axial direction. This advantage is
This can be effectively obtained by making each elastic body short in the axial direction.

[Brief description of drawings]

FIG. 1 is a side view showing a steering device of an automobile that employs a steering damper according to the present invention.

FIG. 2 is an enlarged exploded perspective view of the steering damper shown in FIG.

FIG. 3 is an enlarged partially cutaway side view of the steering damper shown in FIG.

4 is an operation explanatory view of a cross section taken along line 4-4 of FIG.

FIG. 5 is a characteristic diagram obtained by the steering damper according to the present invention.

FIG. 6 is a perspective view of essential parts showing a modified example of the steering damper shown in FIGS. 1 to 3.

FIG. 7 is an operation explanatory view of the steering damper shown in FIG.

FIG. 8 is an enlarged exploded perspective view showing another embodiment of the steering damper according to the present invention.

9 is an operation explanatory view of the steering damper shown in FIG.

10 is an enlarged exploded perspective view showing a modified example of the steering damper shown in FIG.

11 is an operation explanatory view of the steering damper shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Steering damper, 11 ... Tube shaft body, 12 ... Shaft body, 13 ... Elastic body, 13a ... Plane part (1st elastic part), 1
3b ... Cylindrical part (second elastic part).

Claims (4)

[Claims] 1. A steering wheel and a gear which are constituted by interposing an elastic body between a pipe shaft having a non-circular cross section and a shaft body having a non-circular cross section which is inserted into the pipe shaft so as to be rotatable relative to each other by a predetermined amount. In the steering damper interposed in the torque transmission system connecting the boxes, the elastic body is
A first elastic portion that elastically deforms in a first region until the relative rotation amount between the pipe shaft body and the shaft body reaches at least a first set value, and the relative rotation amount is higher than the first elastic portion and has the first relative rotation amount. A steering damper characterized in that a second elastic portion that elastically deforms in a second region from a set value to a second set value is provided in the same cross section substantially orthogonal to the axis. 2. The steering damper according to claim 1, wherein a space formed between the pipe shaft body and the shaft body for accommodating the elastic body has a single arc-shaped portion and both ends thereof. A steering damper, comprising a connecting portion for connection, wherein the first elastic portion is arranged in the connecting portion, and the second elastic portion is arranged in an arcuate portion. 3. The steering damper according to claim 1, wherein a space formed between the pipe shaft body and the shaft body for accommodating the elastic body is opposed to each other, and a pair of vacant spaces and each of these spaces. A steering damper comprising a pair of connecting portions that respectively connect end portions, wherein the first elastic portion and the second elastic portion are arranged in series in the torque transmission direction at both end portions of each connecting portion. 4. The steering damper according to claim 1, wherein a pair of first accommodating portions in which space portions formed between the pipe shaft body and the shaft body for accommodating the elastic body face each other are provided. A pair of second accommodating portions that connect the respective end portions of the first accommodating portion, the first elastic portion that is mainly sheared and deformed is arranged in each first accommodating portion, and the second elastically accommodating portion is mainly compressed and deformed. A steering damper in which the second elastic portion is arranged.