JPS5850105Y2 - elastic shaft joint - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shaft coupling used by being installed between a steering main shaft and a steering gear shaft in, for example, a steering device for an automobile. When the transmission torque is low, it is transmitted through an elastic body such as rubber, and when the torque exceeds a certain level, it is transmitted through direct engagement between the driving shaft and the driven shaft, thereby reducing vibration, impact, and noise. This invention relates to an elastic joint capable of absorbing or damping.

Various types of shaft couplings of this kind, ie, elastic shaft couplings having variable torsional rigidity, have been proposed and put into practice for use in automobile steering systems.

As is well known, regarding automobile steering devices,
Various vibrations and shocks generated by wheels or steering gears rolling on the road are transmitted to the driver operating the steering wheel via the steering main shaft, causing an extremely unpleasant sensation. Therefore, if an elastic joint like the one described above is installed between the steering main shaft and the steering gear shaft to isolate vibrations and shocks, it will be possible to ensure safe operation for the driver. It is valid.

On the other hand, in a steering device, sharp cutting of the bundle is required as one of the other conditions, and for this purpose, it is necessary to ensure high rigidity.

Therefore, the steering device must have good bundle cutting.

One of the important conditions is that there is little influence from vibrations, shocks, etc.

The present invention was made with the aim of satisfying the above-mentioned conditions, and is such that torque transmission from one shaft to the other shaft is performed in at least three stages, and when the torque transmission path is switched. The object of the present invention is to provide an elastic shaft joint that suppresses the occurrence of impact as much as possible.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The elastic shaft joint 1 of this embodiment is applied to a steering device for an automobile, and as shown in FIG. One end of the tube shaft 2 in the elastic shaft joint 1 is connected to the front end of the steering main shaft 8 via the universal joint 11, and one end of the solid shaft 30 The upper end of the steering gear shaft 10 is connected to the upper end of the steering gear shaft 10 by a spline fitting 12.

Note that 13 is a dash board, 14 is a column hole cover that covers the front end of the steering main shaft 8, and 15 is a bracket for attaching the steering column 7.

As shown in FIGS. 2 to 4, the elastic shaft joint 1 includes a hollow tube shaft 2, a solid shaft 3 fitted into the tube shaft 2, and both shafts 2.
, and an elastic body 4 such as rubber interposed between the tube shaft 2 and the solid shaft 3, both of which are made of a material (generally metal) having sufficient rigidity necessary for torque transmission. has been done.

The solid shaft 3 has three arms 5a, 5b, and 5c that extend radially at equal intervals in the circumferential direction from one end to approximately the center, and each adjacent arm 5ay5b, 5c The comrades are connected by a circular arc portion 3a.

Further, the solid shaft 3 has a spline shaft 12a at the other end for spline fitting 12 to the steering gear shaft 10.

On the other hand, the hollow tube shaft 2 into which the solid shaft 3 is inserted is
Each arm 5a of.

5b and 5c with appropriate gaps (
ia, 6bt6c, and the walls of adjacent recesses 6a and Sb t 6e are connected by arc portions 2a.

Further, the tube shaft 2 has a yoke 11a, which is one component of a universal joint 11 for coupling with the steering main shaft 8, at a circular tube portion 2b at one end thereof.

The solid shaft 3 has one arm 5 as shown in FIG.
Elastic bodies 4 are attached to both sides of the other two arms 5a and 5b, excluding c, and to the surface of the circular arc portion 3a, and the elastic bodies 4 are attached at a stage before the solid shaft 3 is inserted into the tube shaft 2. They are bonded by adhesive or vulcanization.

Therefore, when the solid shaft 3 is inserted into the tube shaft 2, the elastic body 4 is interposed between the shafts 2 and 3 as shown in FIG. A concentric relationship is maintained by the elastic body 4 between the parts 3a.

Thus, one arm 5a and a recess 6a opposite thereto.
The elastic body 4 interposed between the two is in close contact with the inner wall surface of the recess 6a, and this close contact state may be either a state in which an appropriate compressive force is applied or a state in which almost no compressive force is applied. .

In addition, another arm 5b and a recess 6b facing it
The elastic body 4 interposed between the two faces the inner wall surface of the recess 6b with a slight gap CI therebetween.

Furthermore, there is a certain gap C2 between the other arm 5c in which the elastic body 4 is not interposed and the recess 6c facing it.
is formed, and this gap C2 is set to be slightly larger than the gap C1 held by the elastic body 4.

This embodiment is constructed as described above, and therefore, in the range of low torque to be transmitted, torque transmission between the two shafts 2 and 3 is performed by the two arms 5a and 5b and the recessed portion 5a p facing them. 5b, and in a high torque range, direct contact between the other arm 5c and the opposing recess 6c.

That is, the steering main shaft 8 and the universal joint 1
When the tube shaft 2 connected via the arm 5a is rotated, the torque is transmitted to the solid shaft 3, and thus to the steering gear shaft 10 side. Then, as the transmitted torque increases, the elastic body 4 is elastically deformed, and the amount of deformation is retained by the elastic body 4 interposed between the other arm 5b and the recess 6b. The recess 6b reaches the gap corresponding to the gap CI.
When the inner wall surface of the elastic body 4 comes into contact with the elastic body 4, the subsequent movement is performed via the two elastic bodies 4 associated with the arms 5a and 5b.

Subsequently, when the transmitted torque further increases and reaches a high torque range above a predetermined value, the two elastic bodies 40 are elastically deformed, and the arm 5c of the elastic body 4, which is not interposed, comes into direct contact with the recess 6c. Therefore, thereafter, torque is transmitted through metal contact between the tube shaft 2 and the solid shaft 3.

That is, the elastic shaft joint 1 of this embodiment has one elastic body 4.
The torque is transmitted through three stages: a first stage by combining the two elastic bodies 4, a second stage by combining the two elastic bodies 4, and a third stage by direct engagement between the arm 5c and the recess 6c. Therefore, the impact at the time of transmission path Q conversion, that is, at the time of switching to each stage, is reduced or alleviated.

Figure 5 shows the rR relationship between the transmitted torque and the relative rotation angle (torsion angle) of both shafts 2 and 3.
The period between B and C is the first stage of torque transmission, the period between B and C is the second stage, and the period after C is the eighth stage.

In addition, in an automobile steering device, the steering main shaft 8 is often in a no-load state or has low torque even if torque is being applied, and in such cases, the tube shaft 2
The elastic body 4 between the solid shaft 3 absorbs or attenuates transmission of vibrations, shocks, noise, etc. caused by wheels or steering gears, etc. to the steering main shaft 8 side, thereby reducing the impact on the driver. Discomfort is removed.

On the other hand, in a high torque range, torque is transmitted through direct contact between the tube shaft 2 and the solid shaft 3, which have sufficient rigidity, so that sharp cutting of the bundle is ensured.

The above-described elastic shaft joint 1 is suitable not only for automobile steering devices but also for devices that require isolation of vibrations between the input side and the output side.

Further, in this embodiment, the arm 5a of the solid shaft 3. 5b, 5c
Although the explanation has been made for the case where there are three arms, it is possible to increase the number of stages of torque transmission by increasing the number of arms.

Furthermore, in this embodiment, the arms 5a and 5b are attached to the solid shaft 3.
, 5c are provided, and a recess 5at6btse is provided in the tube shaft 2, but this relationship is reversed, and an arm is provided on the inner peripheral surface of the tube shaft 2, and a recess that fits with the arm is provided on the outer periphery of the solid shaft 3. It is possible to change it as follows.

As detailed above, in this invention, low torque is transmitted through an elastic body, and torque above a certain level is transmitted through direct contact between the tube shaft and the solid shaft. In addition to being able to absorb or attenuate noise, it can also demonstrate sufficient durability and reliability even in the high torque range.In particular, the present invention is capable of transmitting torque from one shaft to the other in at least three stages. By stepping on the switch, it is possible to suppress the occurrence of impact when switching the torque transmission path, and there is an advantage that smooth torque transmission can be carried out.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and Fig. 1 is an explanatory diagram showing the state in which the elastic shaft joint is assembled into an automobile steering device, and Fig. 2 shows the elastic shaft joint before the solid shaft is inserted into the tube shaft. Fig. 3 is a front view of the elastic shaft joint, Fig. 4 is a sectional view taken along the line IV-IV in Fig. 3, and Fig. 5 shows the transmitted torque and the relative rotation angle between the tube shaft and the solid shaft. It is a graph showing the relationship between. 1...Elastic shaft coupling, 2...Pipe shaft, 3...
...Solid shaft, 4...Elastic body, 5a, 5b, 5
b...Arm, 6a, 6b, 6c...
recess.

Claims (1)

[Scope of utility model registration request] It consists of a tube shaft, a solid shaft inserted into the tube shaft, and an elastic body interposed between these two shafts, and there is a radially extending member on either the tube shaft or the solid shaft. At the same time, the other arm is formed with a recess that fits with these arms with an appropriate gap, and all the arms other than at least one of the arms are opposed to them. An elastic body is interposed between each of the arms and the inner wall surface of the recess, at least one of the elastic bodies is brought into close contact with the arm and the inner wall surface of the recess that opposes the arm, and at least one other elastic body is A slight gap is formed between the arm or the inner wall surface of the recess, and a gap slightly larger than the gap provided by the elastic body is formed between the arm and the inner wall surface of the recess where the elastic body is not interposed. Features an elastic shaft joint.