JPH0533433Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a steering device employed in an automobile, and more specifically, the present invention relates to a steering device employed in an automobile.
The present invention relates to a connection structure in which only the rotational direction strength is increased without increasing the axial direction strength in an intermediate shaft of a steering device that connects a steering shaft and a main shaft to which a steering wheel is connected.

[Conventional technology]

The steering device is a device that transmits the rotation of the steering wheel to a steering gear box and then to the wheels via, for example, a rack and pinion mechanism within the box. If the steering wheel is connected directly to the gear shaft, there is a risk that the steering wheel will be pushed up in the event of a collision. Therefore, conventionally, the main shaft and the gear shaft are connected by an intermediate shaft configured to be slidable in the axial direction to prevent the above-mentioned thrust up.

Conventionally, as such an intermediate shaft connection structure, as disclosed in, for example, Japanese Utility Model Application Publication No. 60-100262, a solid shaft is inserted into a hollow shaft, and the fitting portions of the two have different diameter cross sections. This allows rotational force to be transmitted and also allows for sliding in the axial direction. Conventionally, as shown in FIG. 6, serrations 6 are formed on the outer peripheral surface of the inner shaft 1 and the inner peripheral surface of the outer shaft 2, which constitute the intermediate shaft, and the rotation of the steering wheel is controlled by the engagement of these serrations. There is a structure that allows transmission to the steering gear shaft side and allows sliding in the axial direction.

By the way, in general, when the above-mentioned cross-sections with different diameters or serrations are used for connection, there is a slight play in the direction of rotation due to the structure, and with long-term use, this play becomes large and has a negative impact on maneuvering response. There are concerns about giving.

In order to prevent this backlash, the structure described in the above-mentioned publication has grooves formed in the solid shaft, and in the transmission structure shown in FIG. There is a structure in which grooves 3 extending in the direction are formed, and resin 4 is injected and solidified into these grooves to prevent play in the rotational direction between the hollow shaft and the intermediate shaft, or between the inner shaft and the outer shaft. Proposed.

In these resin-injected structures, this resin acts as a stopper to prevent rattling in the rotational direction.
In addition, when an impact force of a predetermined value or more is applied to the steering gear shaft in the event of an accident, the resin stopper is cut off, and the inner shaft slides within the outer shaft, thereby preventing the steering wheel from being pushed up.

[Problem that the invention attempts to solve]

However, recently, larger tires are sometimes used, and the input from the steering gear shaft side increases, especially when driving on rough roads. It may be sheared at the adhesive surface with 3.
There is a possibility that the occurrence of rattling between seresins cannot be completely prevented.

In order to prevent such problems, it is conceivable to increase the shear resistance of the resin stopper by widening the groove and increasing the diameter of the resin injection hole into the groove.

However, in this case, not only the shear resistance in the rotational direction of the resin stopper but also the shear resistance in the axial direction becomes large.
The original function of this serration fitting, that is, the function of preventing the inner shaft and the outer shaft from sliding and contracting against each other in response to an axial external force exceeding a predetermined value, is impaired.

Therefore, in view of the above problems, the purpose of this invention is to absorb the impact when the impact in the axial direction exceeds a predetermined value, and to transmit the input acting on the steering gear shaft side to the steering wheel side. It is an object of the present invention to provide an intermediate shaft connection structure for a steering device that can firmly withstand torsional input in the rotational direction and completely prevent the occurrence of rattling in the rotational direction. It is in.

[Means for solving problems]

The present invention provides an intermediate shaft connection structure for a steering device in which a steering gear shaft and a main shaft are connected by an intermediate shaft consisting of an inner shaft and an outer shaft that are slidably fitted in serrations. A suitable number of annular grooves extending along the direction are formed, and an appropriate number of axial grooves extending along the axial direction are formed in communication with the annular groove, and a connection between these grooves and the outer shaft is formed. It is characterized by injecting and solidifying resin into the space formed by the serrations.

[Effect]

In the intermediate shaft connection structure of the steering device according to the present invention, an axial groove is formed by communicating with a conventional annular groove, and the resin stopper injected and solidified into this axial groove is sheared in the circumferential direction. The force determines the resistance in the rotational direction. The shearing force in the circumferential direction of the resin stopper in this axial groove is extremely large, and therefore a large resistance force is generated against torsional force in the rotational direction, resulting in the above-mentioned increase in tire size.
The problem of shearing of the resin stopper due to driving on rough roads, etc. can be reliably prevented. On the other hand, when viewed in the axial direction, the resin in the axial concave grooves is only applied to the inner surface of the serrations of the outer shaft, so there is almost no resistance in the axial direction, and therefore the above-mentioned axial impact force inherent to the intermediate shaft It does not adversely affect absorption function.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 are diagrams for explaining an intermediate shaft connection structure of a steering device according to an embodiment of the present invention.

In FIG. 4 showing a steering device in which the structure of this embodiment is adopted, 10 is a steering wheel, and a main shaft 11 is fixed to this steering wheel 10, and the main shaft 11 is rotated by a support tube 12. freely supported. The support tube 12 is fixed to the vehicle body 15 via a bracket 14. The main shaft 11 is connected to a steering gear shaft 17 via a universal joint 28a, an intermediate shaft 16, and a universal joint 28b. The structure is such that it is transmitted to

As shown in FIG. 1, the intermediate shaft 16 consists of a solid inner shaft 18 and a hollow outer shaft 19, and serrations 20 and 21 are formed on the front half of the outer surface of the inner shaft 18 and on the inner surface of the outer shaft 19, respectively. is formed,
Both are slidably fitted in the axial direction, and the rotation of the outer shaft 19 attached to the main shaft 11 is transmitted to the inner shaft 18.

And serration 2 of inner shaft 18
At a predetermined location on the outer peripheral surface portion where the number
As shown in the figure, two annular grooves 22 are formed substantially perpendicular to the axial direction, that is, along the circumferential direction, and an axial groove that connects both of the annular grooves 22. 23 is formed in the axial direction.
Further, a resin injection port 24 is formed at a predetermined location of the outer shaft 19 facing the annular groove 22 of the inner shaft 18 . These annular grooves 22 and axial grooves 23 and the outer shaft 1
A resin is injected and solidified between the serrations 21 and the annular stopper 25a.
and an axial stopper 25b.

Next, the effects of this embodiment will be explained.

In the structure of this embodiment, the steering wheel 10
The rotational movement is transmitted from the main shaft 11 to the gearbox 29 via the intermediate shaft 16 and gear shaft 17.
In this case, a resin stopper 25 is formed on the intermediate shaft 16 by injection of resin, so that no backlash occurs between the inner shaft 18 and the outer shaft 19 under normal operating conditions.

Furthermore, in the past, when a relatively large torsional force was applied to the intermediate shaft 16 due to an increase in tire size, there was a risk that the resin stopper would shear. On the other hand, in the structure of this embodiment, since the shearing force in the rotational direction of the axial stopper 25b injected and solidified into the axial groove 23 is very large, there is little risk of the above-mentioned shearing. Therefore, there is no play in the rotational direction, and as a result, the steering wheel 1
Steering gear shaft 17 ensures reliable operation on the 0 side.
Transmitted to the side, the driving operation will not be degraded.

On the other hand, if an impact force of more than a predetermined value is applied in the axial direction, the resin in the injection port 24 is sheared, and the intermediate shaft 16
contracts in the axial direction. In this case, the axial resin stopper 25b has very low axial shearing resistance due to its structure, and if an impact force of more than a predetermined value is applied from the steering gear shaft 17 side due to an accident, the resin stopper 25b The inner shaft 18 is sheared by an axial external force of the same magnitude as that of the inner shaft 18, and the inner shaft 18 is further inserted and housed in the outer shaft 19. This absorbs the impact force and prevents the steering wheel 10 from being pushed up.

In the above embodiment, a pair of annular grooves 22 were provided and the two were communicated through an axial groove 23, but in the present invention,
The number, shape, etc. of the annular groove 22 and the axial groove 23 may be appropriately selected depending on the purpose.
For example, as shown in another embodiment in FIG. 5, the axial groove 27 may be communicated with only one of the annular grooves 22. In this case as well, substantially the same effects as in the embodiments shown in FIGS. 1 to 4 can be obtained.

In yet another embodiment, it is also possible to form only one annular groove 22; in such a case,
Annular groove 22 on only one side of the embodiment shown in FIG.
The structure is such that an axial groove 27 is formed.

[Effect of idea]

As described above, according to the intermediate shaft connection structure of the steering device according to the present invention, the annular groove is formed in the fitting surface of the inner shaft, and the axial groove extending substantially parallel to the axial direction is replaced with the annular groove. Since these grooves were injected and filled with resin, the axial shearing resistance of the resin remained the same.
It is possible to greatly increase only the resistance force in the rotational direction, absorb the impact force acting in the axial direction at the time of impact as before, and still be able to withstand even if the torsional force acting on the intermediate shaft increases due to increases in tire size, etc. This has the effect of being able to reliably prevent the occurrence of such problems, and thus maintaining good driving performance forever.

[Brief explanation of the drawing]

1 to 4 are diagrams for explaining an intermediate shaft connection structure of a steering device according to an embodiment of the present invention, in which FIG. 1 is a partially sectional side view of the intermediate shaft, and FIG. 2 is a side view of the inner shaft. 3 is a partial enlarged sectional view of an axial groove, FIG. 4 is a side view of a steering device to which the structure is applied, and FIG. 5 is an enlarged view of main parts showing another embodiment. FIG. 6 is a partially sectional side view showing a conventional example. In the figure, 10 is a steering wheel, 11
is the main shaft, 16 is the intermediate shaft, 17 is the gear shaft, 18
is the inner shaft, 19 is the outer shaft, 2
0 and 21 are serrations (fitting surfaces), 22 is an annular groove, 23 and 27 are axial grooves, 25 is a resin stopper, and 29 is a steering gear box.

Claims (1)

[Scope of utility model registration request] By inserting the inner shaft into the outer shaft and engaging the intermediate shaft with serrations, rotational force can be transmitted between the gear shaft connected to the steering gear box and the main shaft connected to the steering wheel. In an intermediate shaft connection structure of a steering device in which axial force cannot be transmitted, an annular groove extending along the circumferential direction is formed on a fitting surface of the inner shaft, and
an axial groove that extends along the axial direction and communicates with the annular groove; an injection port is formed in a portion of the outer shaft that faces at least one of the grooves; An intermediate shaft connection structure for a steering shaft device, characterized in that a resin is injected and filled from the injection port into the space formed by the serrations.