JP4543802B2 - Steering gear mounting structure - Google Patents

Description

  The present invention relates to a structure for mounting a steering gear to a vehicle body side member.

A steering gear, in particular, a gear housing that accommodates a rack and extends in the vehicle width direction is elastically supported by the vehicle body side member with a structure as described in Patent Document 1, for example. Explaining the structure, a plurality of overhang portions (attachment portions) are provided in the housing, and attachment holes are formed in the overhang portions that open in the direction perpendicular to the rack axis. A bush is press-fitted into the attachment hole, and is attached to the vehicle body side member via a bolt inserted into the bush and elastically supported. The bush includes an inner cylinder made of a metal member and an insulator (elastic body) bonded to the inner cylinder on the outer diameter surface.
Japanese Utility Model Publication No. 5-92047

  When the rack shaft of the steering gear and the mounting hole are offset up and down as in the conventional example, that is, when the rack shaft and the elastic support portion are offset up and down, the steering wheel is steered. When the force in the vehicle longitudinal direction acts on the steering gear, the shaft center of the steering gear swings in the vehicle longitudinal direction about the elastic support point due to the force in the vehicle longitudinal direction as the rigidity of the insulator decreases. As a result, the vehicle responsiveness during steering may be adversely affected.

For example, as shown in FIG. 1, if the column shaft is bent, the force in the vehicle longitudinal direction from the column shaft is transmitted separately from the shaft rotation according to the steering wheel steering when the force is transmitted at the column joint. Is input to the steering gear.
Further, by increasing the rigidity of the insulator, the swing of the steering gear can be suppressed to a small level. However, as the rigidity is increased, the vibration transmitted from the wheel to the steering wheel may increase.
The present invention focuses on the above points, and suppresses the vibration transmitted from the wheels to the steering wheel and suppresses the tilt of the steering gear in the vehicle front-rear direction, thereby improving the response during steering. It is an issue.

In order to solve the above-described problems, the present invention provides an inner cylinder disposed in an attachment hole provided in a gear housing of a steering gear, and a cylindrical insulator is interposed between the attachment hole and the inner cylinder. And a steering gear mounting structure in which the gear housing is mounted on a vehicle body side member via a mounting bolt penetrating the inner cylinder, and the shaft of the mounting hole is directed in the vehicle front-rear direction and both axial ends of the insulator The flange portion is provided with a flange portion, and the rigidity of the insulator is higher than the rigidity of the insulator main body portion positioned between the inner surface of the mounting hole and the outer surface of the inner cylinder, and the flange portion Provided with a rigidity ratio adjusting means for lowering the rigidity in the vehicle width direction than the rigidity in the vehicle longitudinal direction. It is obtained by being a plurality of protrusions formed on at least one surface of the surface facing the vehicle longitudinal direction.

According to the present invention, the load in the vehicle front-rear direction can be received mainly by the flange portion by directing the mounting hole in the vehicle front-rear direction. And, while setting the rigidity of the insulator body part to a low rigidity according to the vibration suction from the wheel, while setting the rigidity of the flange part high, while suppressing the vibration transmitted from the wheel to the steering wheel, The steering gear can be prevented from falling in the longitudinal direction of the vehicle, and the response at the time of steering can be improved.
Furthermore, since the rigidity ratio adjusting means, which is a plurality of convex portions, is formed on at least one surface of the flange portions facing the vehicle front-rear direction, the flange portion has a vehicle width direction relative to the vehicle front-rear direction rigidity. Even if the rigidity of the flange part is adjusted to be low and the rigidity of the flange part is set higher than that of the insulator body part, the rigidity of the flange part in the vehicle width direction is relatively low, and the steering gear is prevented from swinging in the longitudinal direction of the vehicle. Even if the rigidity of the flange portion is increased, the rigidity of the flange portion in the vehicle width direction can be set to be low, and the design of the rigidity of the insulator can be facilitated.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 and FIG. 2 are diagrams showing an example of the configuration of a steering device, in which the steering of the steering wheel 1 is transmitted to the pinion shaft of the steering gear 3 via the steering column 2, and then the rack shaft meshes with the pinion shaft. 14 and the rack shaft 14 moves horizontally in the vehicle width direction, whereby the left and right steered wheels are steered via the tie rods.

Here, from the relationship of layout and the like, as shown in FIG. 1, the steering column 2 is constituted by a plurality of columns 2 and the columns 2 are connected by joint members 4.
The steering gear 3 is accommodated in a gear housing 5, and the gear housing 5 is mounted and elastically supported on a frame 6 which is a vehicle body side member as shown in FIGS.

Next, the mounting structure will be described with reference to FIG.
A mounting portion 7 is formed in the gear housing 5 at a position offset vertically from the rack shaft 14. Two mounting holes 7a are formed in the mounting portion 7 so as to be aligned in the vehicle width direction with their axes directed in the vehicle longitudinal direction. An inner cylinder 8 is arranged coaxially with respect to each of the mounting holes 7a. The end surface of the mounting portion 7 facing the vehicle front-rear direction is a flat surface, and the axial length of the inner cylinder 8 is longer than the axial length of the mounting hole 7a.

  A cylindrical insulator 9 is interposed between the mounting hole 7 a of the mounting portion 7 and the inner cylinder 8 in a press-fitted state. The insulator 9 includes an insulator main body 9a having substantially the same length as the mounting hole 7a, and disk-shaped flange portions 9b and 9c arranged on both sides of the insulator main body 9a. In this embodiment, in order to suppress vibration transmitted from the wheel to the steering wheel 1, the rigidity of the insulator main body 9a is set low so as to have a value corresponding to the vibration, and the front and rear of the steering gear 3 in the vehicle. In order to suppress the swing in the direction, the rigidity of the flange portions 9b and 9c is set to be higher than the rigidity of the insulator main body portion 9a. That is, the rigidity of the flange portions 9b and 9c is set higher than that of the insulator main body portion 9a.

Here, as described above, the means for differentiating the rigidity of the insulator body 9a and the flanges 9b and 9c may be composed of different materials, or even if the same material is used, currants, iron cores, etc. This may be carried out by adjusting the rigidity by providing. Moreover, in the said embodiment, in order to make assembly | attachment and rigidity adjustment of the insulator 9 easy, the insulator main-body part 9a and the flange parts 9b and 9c are made into a different body, However, The said insulator main-body part 9a and at least one flange part 9b and 9c may be integrally formed.
Further, the mounting portion 7 for mounting the gear housing 5 on the frame 6 is formed integrally with the gear housing 5, but may be a separate body.

Then, with the insulator 9 and the inner cylinder 8 disposed in the mounting hole 7a as described above, as shown in FIG. 4, the bolt 11 is fastened to the frame 6 that is the vehicle body side member.
Explaining the mounting structure, the sleeve 10 into which the bolt 11 can be inserted is attached to the frame 6 with the shaft directed in the vehicle front-rear direction. The sleeve 10 has a recessed portion 10a on the side of the mounting portion 7 in which the inner cylinder 8 can be clamped coaxially. With the end of the inner cylinder 8 fitted in the recess 10a, the bolt 11 is passed through the sleeve 10 and the inner cylinder 8, and a nut 12 is screwed into the tip of the bolt 11 and fastened. Thus, the mounting portion 7 is mounted on the frame 6. In FIG. 4, reference numeral 13 denotes a washer.

  Thus, the two flange portions 9b and 9c of the insulator 9 are interposed with one flange portion 9b between the end surface 7b of the mounting portion 7 and the washer 13 with the plate thickness direction directed in the vehicle longitudinal direction. The other flange portion 9c is inserted between the end surface 7c of the attachment portion 7 and the wall surface of the frame 6 with the plate thickness direction directed in the vehicle front-rear direction.

Next, the operational effects of the above configuration will be described.
By setting the shaft of the attachment hole 7a in the vehicle width direction, it is possible to load the load in the vehicle front-rear direction mainly by the flange portions 9b and 9c.
In the mount structure configured as described above, the rigidity of the flanges 9b and 9c is set to be higher than that of the insulator main body 9a, so that the rigidity in the vehicle front-rear direction is suppressed while keeping the rigidity in the vehicle width direction low according to the vibration targeted. Set high. In other words, by receiving the force in the vehicle width direction mainly by the insulator body 9a, the rigidity in the vehicle width direction can be set to a rigidity suitable for suppressing vibrations input from the wheels, and the force in the vehicle front-rear direction is 2 By mainly receiving the flange portions 9b and 9c, the swing of the steering gear 3 around the elastic support point in the vehicle front-rear direction can be reduced.

That is, the vibration transmitted from the wheel is absorbed by the insulator main body 9a and the vibration transmitted to the steering wheel 1 is suppressed.
On the other hand, in the case of a column structure in which the columns 2 are connected by the joint member 4, the steering gear 3 is centered on the elastic support portion P when the steering wheel 1 is steered as the bending angle at the joint portion increases. As the steering wheel 1 swings, the steering gear 3 swings in the vehicle front-rear direction as the rigidity of the insulator 9 decreases as the force that swings in the vehicle front-rear direction acts. Occurs.

On the other hand, in the mount structure of this embodiment, the swing in the vehicle longitudinal direction is mainly received by the flange portions 9b and 9c of the insulator 9, but the rigidity of the flange portions 9b and 9c is set high. As a result, the flange portions 9b and 9c suppress the tilting of the steering gear 3 in the vehicle front-rear direction during steering, thereby improving the response during steering.
Here, the flange portions 9b and 9c mainly contribute to the rigidity in the vehicle front-rear direction, but also contribute to the rigidity in the vehicle width direction. Therefore, the rigidity of the flange portions 9b and 9c is larger than the rigidity in the vehicle front-rear direction. It is desired to change the rigidity ratio of the flange portions 9b and 9c in the vehicle front-rear direction and the vehicle width direction so as to reduce the rigidity in the vehicle width direction.

From this point of view, as shown in FIGS. 5 and 6, it is preferable to provide a plurality of ribs 15 that are convex portions on at least one surface of the flange portions 9b, 9c facing the vehicle front-rear direction.
The rib 15 constitutes a rigidity ratio adjusting means, and when a force in the in-plane direction acts on the flange portions 9b and 9c, a shear stress acts on the rib 15 and the rib 15 easily deforms in the direction of the force. As a result, the rigidity in the in-plane direction becomes weaker than that in the perpendicular direction. That is, by forming the rib 15, the flange portions 9 b and 9 c are adjusted so that the rigidity in the vehicle width direction is lower than the rigidity in the vehicle front-rear direction. Thus, even if the rigidity of the flange portions 9b and 9c is set higher than that of the insulator main body portion 9a, the rigidity in the vehicle width direction of the flange portions 9b and 9c is set to be relatively low, so Even if the rigidity of the flange portions 9b and 9c is increased to suppress the swinging of the flange portion 9b, the rigidity in the vehicle width direction of the flange portions 9b and 9c can be set low, and the rigidity design of the insulator 9 becomes easy.

  Here, the rib 15 is preferably provided in a portion positioned above and below the inner cylinder mounting hole 9d opened in the insulator 9, that is, within a range of a width H in FIG. This range is a portion that receives a load more effectively when the bolt 11 is tightened, and by limiting the range in which the ribs 15 are provided, the load applied to each rib 15 increases and the above effect can be increased. is there.

  The ribs 15 are preferably formed to extend in the vertical direction as shown in FIG. That is, it becomes easy to deform in the vehicle width direction by relatively narrowing the lateral width of each rib 15 against the shearing force in the in-plane direction, but it becomes difficult to deform in the vertical direction by extending in the vertical direction. . Thus, even if the ribs 15 are provided, it is possible to suppress a decrease in the rigidity in the vertical direction while reducing the rigidity in the vehicle width direction.

  Here, when the steering gear 3 is about to swing in the vehicle front-rear direction around the elastic support portion, the flange portions 9 b, 9 c have a vertical direction (vehicle front-rear direction) force and a vertical direction. Shear force also acts. Therefore, even if the rib 15 is provided, it is possible to more effectively suppress the swing in the vehicle front-rear direction around the elastic support portion P of the steering gear 3 by suppressing the decrease in rigidity in the vertical direction.

The rib 15 does not necessarily extend up and down . Further, the convex portion as the rigidity ratio adjusting means is not limited to the belt-like rib 15 but may be other shapes such as a dot shape.
Further, the rib 15 has a rectangular cross section as shown in FIG. 6, but is not limited thereto, and may be, for example, a triangular cross section or a semicircular cross section.

Next, the effect of the rib 15 that is the convex portion will be described. Two types of flange portions 9b and 9c are prepared for the number of the ribs 15 as shown in FIG. 5 and the number of the ribs 15 as shown in FIG. A test was conducted on the change in rigidity caused by changing the protrusion amount A.
The results are shown in Table 1. In addition, the change rate in the table | surface has shown the change rate of the rigidity with respect to the case where the rib 15 is not provided.

As can be seen from Table 1, it can be seen that the ratio between the rigidity in the vehicle width direction and the rigidity in the vehicle front-rear direction can be adjusted by adjusting the number of ribs 15 and the protrusion amount A.
Table 2 shows the results when only the rigidity of the insulator 9 itself constituting the flange portions 9b and 9c (including the ribs 15) is changed.

  As can be seen from Table 2, when the ribs 15 are provided, the rigidity in the vehicle width direction and the front and rear of the vehicle can be changed by changing the rigidity of the insulator 9 itself without changing the number of the ribs 15 and the protruding amount A. It can be seen that the ratio to the direction stiffness can be adjusted.

It is a side view which shows the steering structure which concerns on embodiment based on this invention. It is a figure which shows the attachment part of the steering gear which concerns on embodiment based on this invention. It is a figure which shows attachment of the steering gear which concerns on embodiment based on this invention. It is sectional drawing which shows attachment of the steering gear which concerns on embodiment based on this invention. It is a front view which shows the flange part which concerns on embodiment based on this invention. It is XX sectional drawing in FIG. It is a front view which shows another flange part which concerns on embodiment based on this invention.

Explanation of symbols

1 Steering wheel 2 Column 3 Steering gear 5 Gear housing 6 Frame (vehicle body side member)
7 Mounting portion 7a Mounting hole 7d Inner tube insertion hole 8 Inner tube 9 Insulator 9a Insulator body 9b, 9c Flange portion 11 Bolt 12 Nut 13 Washer 15 Rib (convex portion)

Claims (4)

An inner cylinder is disposed in an attachment hole provided in the gear housing of the steering gear, and a cylindrical insulator is interposed between the attachment hole and the inner cylinder, and via an attachment bolt penetrating the inner cylinder. In the steering gear mounting structure in which the gear housing is mounted on the vehicle body side member,
Insulator main body with the shaft of the mounting hole oriented in the vehicle longitudinal direction and flange portions provided at both axial end portions of the insulator, and the rigidity of the insulator between the mounting hole inner diameter surface and the inner cylinder outer diameter surface The rigidity of the flange portion is higher than the rigidity of the portion, and the flange portion is provided with a rigidity ratio adjusting means for lowering the rigidity in the vehicle width direction than the rigidity in the vehicle front-rear direction. A steering gear mount structure, comprising: a plurality of convex portions formed on at least one surface of the flange portion facing the vehicle longitudinal direction . 2. The steering gear mounting structure according to claim 1, wherein the insulator main body portion and the flange portion are separated. 2. The steering gear mount structure according to claim 1, wherein the convex portion of the rigidity ratio adjusting means extends in a vertical direction. The steering gear mount structure according to claim 1 or 3, wherein the formation range of the convex portion of the rigidity ratio adjusting means is an upper portion and a lower portion sandwiching an inner cylinder insertion hole of the insulator. .

Images