JPH08198122A - Steering shaft supporting structure - Google Patents

Abstract

PURPOSE: To prevent generation of striking or sliding noises and prevent rattling by fitting a dust shield boot made of a flexible material on the outer race of a rolling bearing interposed between the outer race and an inner race fitted on a steering shaft which is mounted on a toe board. CONSTITUTION: A seal is provided between a through hole 44 and an intermediate steering shaft 20 and a supporting device 46 has a flange 50a formed at its one end and a dust shield boot 50 made of a flexible material such as rubber fixed air-tightly is installed on a toe board 42 at the peripheral edge of the through hole 44 through a ring-shaped holder plate 48. A cover or an aux. boot 70 made of a flexible material such as rubber having a relatively thin wall thickness is installed on the outside of this car cabin 32, and one end of the cover or aux. boot is secured to the toe board 42 together with the flange 50a, while the detention end in flange form on the other side is secured by a plurality of hooks 76. The inner cylindrical part 52 of the dust shield boot 50 holding a rolling bearing 56 deflects freely in the folded-back part to admit irregular motions smoothly, and no noises will be generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering shaft support structure for a vehicle, especially for an automobile.

[0002]

2. Description of the Related Art A steering shaft in an ordinary automobile is composed of an upper steering shaft having a steering wheel mounted on an upper end thereof in view of a vehicle layout.
The upper steering shaft is divided into an intermediate steering shaft that is connected to the lower end of the upper steering shaft through a universal joint, and the intermediate steering shaft penetrates a toe board or a dash panel that divides the vehicle compartment from the engine room. It is customary that the lower end of the steering gear box extends in the room and is connected to the input shaft of a steering gear box arranged in the engine room via a universal joint. A hook type universal joint having a simple structure is widely adopted as the universal joint connecting the upper steering shaft and the intermediate steering shaft and the universal joint connecting the intermediate steering shaft and the input shaft of the steering gear box.

In the portion where the intermediate steering shaft penetrates the toe board, of course, a smooth rotational displacement around its own axis, which is necessary for the original steering function of the steering shaft, is ensured, and dust and muddy water in the engine room are secured. Alternatively, it is necessary to provide a sufficient seal so that hot air, engine noise, tire noise during traveling, etc. do not enter the vehicle interior. Now, a typical structure of a portion where a conventional steering shaft penetrates a toe board will be described with reference to FIG. 5. In the figure, reference numeral 1 indicates an upper steering shaft (not shown) with its upper end through a universal joint.
An intermediate steering shaft 2 connected to an input shaft of a steering gear box (not shown) provided in the engine room through a universal joint, and divides a vehicle compartment 3 and an engine room 4 from each other. The toe board or dash panel 5 is a through hole that is opened in the toe board 2 and allows the intermediate steering shaft 1 to be inserted with sufficient clearance, and 6 is one end of which is bolted to the toe board 2 at the periphery of the through hole 5. 7 (only the center line is shown)
The rubber seal member 8 is tightly fixed by means of a bearing bush 8 made of a resin material, which is press-fitted into a cylindrical portion 6a formed near the other end of the rubber seal member 6 or adhered and fixed by baking or the like, and has a central hole 8a. The intermediate steering shaft 1 is rotatably inserted therein. At the end of the rubber seal member 6 on the engine room 4 side, a seal lip 6b is provided that is pressed against the outer peripheral surface of the intermediate steering shaft 1.

In the above-mentioned conventional structure, when the intermediate steering shaft 1 is rotated by steering, the shaft 1 is connected to the upper steering shaft and the input shaft of the steering gear box through the hook type universal joints at both upper and lower ends thereof. , Not only the rotational displacement about its own axis,
Since its own axis is accompanied by an irregular motion such as a slurping motion, the bearing bush 8 hits the bearing bush one-sided, and the bearing bush 8 is unevenly worn. There is a problem that rattling that impairs the steering feeling occurs at an early stage, and there is a drawback that a sliding noise (rubbing noise) is generated between the lip 6b of the rubber seal member 6 and the intermediate steering shaft 1.

[0005]

SUMMARY OF THE INVENTION The present invention effectively prevents generation of hammering noise and sliding noise, which are the drawbacks of the above-mentioned conventional steering shaft supporting structure, that is, the supporting structure of the portion where the steering shaft penetrates the toe board. In addition, it is an object of the present invention to provide a steering shaft support structure that can prevent rattling due to wear of the bearing device, improve steering feeling, and have excellent durability.

[0006]

The present invention was devised in order to achieve the above-mentioned object, and a steering shaft which penetrates a through hole provided in a toe board with a play,
A rolling bearing having an inner race externally fitted to the steering shaft, an outer race concentrically arranged outside the inner race, and a rolling member such as a ball interposed between the inner race and the outer race. And a dustproof boot made of a flexible material such as rubber, one end of which is closely fixed to the through hole peripheral portion of the toe board and the other end of which is externally fitted to the outer race of the rolling bearing. A support structure is provided.

In the present invention, it is preferable that the outer race of the rolling bearing is closely fitted in an annular groove of a holding portion formed in the other end portion of the dustproof boot and having a U-shaped cross section. Also, it is preferable that a dustproof and waterproof seal member is mounted in at least the annular space on the outer side of the vehicle interior of the rolling bearing. Further, a small-diameter inner cylinder portion that is folded back and extends outward of the vehicle compartment is formed at the other end portion of the dustproof boot, and a holding portion having a U-shaped cross section is formed inside the inner cylinder portion. Preferably.

[0008]

According to the present invention, the intermediate steering shaft is supported by the inner race of the rolling bearing having the outer race held at the other end of the dustproof boot, one end of which is closely adhered and fixed to the peripheral edge of the through hole of the toe board. Therefore, the steering rotation of the intermediate steering shaft is performed extremely smoothly, and even if the intermediate steering shaft performs irregular movement such as rasping movement, no hammering noise is generated between the rolling bearing and the intermediate steering shaft. Moreover, since the intermediate steering shaft does not come into contact with the lip of the rubber seal, sliding noise does not occur. Furthermore, by interposing a dustproof and waterproof seal member in the annular space on the outer side of the vehicle interior of the rolling bearing, the airtight shield between the vehicle interior and the engine room is surely performed, and the engine room is also provided. The noise generated inside the vehicle is prevented from propagating to the passenger compartment. Furthermore, since rusting of the rolling bearing is prevented, sufficient durability can be ensured.

[0009]

Embodiments of the present invention will be specifically described below with reference to FIGS. First, in the schematic configuration diagram of FIG. 1, a steering shaft generally indicated by reference numeral 10 includes an upper steering shaft 14 having a steering wheel 12 mounted at one end, a hook type universal joint 16 and a flexible coupling 18 known per se. The intermediate steering shaft 20 is connected to the input shaft of the steering gear box 24 via a hook type universal joint 22. The upper steering shaft 14 is rotatably supported by a bearing (not shown) provided in a steering column 26, and the steering column 26 is provided in a vehicle compartment 32 via an upper bracket 28 and a lower bracket 30. It is attached to the frame 34 for the instrument panel. A column cover 36 is arranged outside the steering column 26.

The intermediate steering shaft 20 has a through hole 44 formed in a toe board or a dash panel 42 which divides the vehicle compartment 32 from the steering gear box 24 and an engine room 40 accommodating an engine, a transmission and the like (not shown). It penetrates with sufficient clearance, and the through hole 44 and the intermediate steering shaft 2
A seal and support device, indicated generally by the reference numeral 46, is interposed between the two.

As shown in the sectional view of FIG. 2 and the front view of FIG. 4, the seal and support device 46 has a flange 50a formed at one end thereof at the peripheral portion of the through hole 44. The toe board 42 is provided with a dustproof boot 50 made of a flexible material such as rubber, which is airtightly and tightly fixed to the toe board 42 by fixing means such as bolts and screws via an annular pressing plate 48. The other end of the dustproof boot 50 is folded back to form a small-diameter inner cylinder portion 52 extending toward the engine room 40, and a holding portion having a U-shaped cross section on the inner peripheral surface of the inner cylinder portion 52. 54
Is provided.

The holding portion 54 holds a rolling bearing generally designated by the numeral 56, and the rolling bearing 56 is shown in FIG.
As shown in the enlarged cross-sectional view of FIG. 1, an annular inner race 58, an annular outer race 60 concentrically arranged with respect to the inner race 58, and rolling between the inner race and the outer race are possible. A large number of balls,
The outer race 6 including a rolling member 62 such as a roller.
0 is elastically fitted and held in the holding portion 54 having a U-shaped cross section, and the intermediate steering shaft 20 is press-fitted into the inner race 58. A V-shaped groove 64 is provided on the outer peripheral surface of the inner race 58, and a concave groove 66 is provided on the inner peripheral surface of the outer race 60, so that the outer peripheral edge of an annular seal member 68 made of a flexible material such as rubber is provided. The annular space between the inner race 58 and the outer race 60 is made watertight by fitting in the concave groove 66 and by fitting the inner peripheral edge having a Y-shaped cross section into the V-shaped groove 64. Sealed. In FIG. 3, the seal members 68 are attached to both sides of the rolling member 62, but the seal members 68 may be attached only to the outside of the vehicle compartment, that is, the engine room 40 side.

A cover or an auxiliary boot 70 made of a relatively thin flexible material such as rubber is attached to the outside of the dustproof boot 50 on the side of the passenger compartment 32. One end of the cover 70 is the pressing plate 48. Together with the flange 50a of the dustproof boot 50, the flange-shaped locking end 74 of the inner cylindrical portion 72, which is fastened together with the toe board 42 at the peripheral edge of the through hole and is folded back and extends toward the engine room, It is locked and fixed by a plurality of hooks 76 projecting from an annular wall on the vehicle compartment side forming the holding portion 54. Note that FIG.
Further, in FIG. 4, reference numeral 78 is a positioning projection protruding from the flange 50a of the dustproof boot 50, and 80 is an annular lip protruding from the engine room side end of the holding portion 54 of the dustproof boot 50. Foreign matter such as muddy water and flying stones,
It is intended to prevent the seal member 68 of the rolling bearing 56 from directly hitting and damaging the seal member 68, and is formed so as not to contact the outer peripheral surface of the intermediate steering shaft 20.

According to the above construction, the intermediate steering shaft 20 is supported by the inner race 58 of the rolling bearing 56, and can freely and smoothly rotate around its own axis during steering. Further, when steering, the intermediate steering shaft 20 performs a motion such as a shaving motion in which its own axis tilts, or an irregular motion that revolves around a virtual axis different from its own axis. Since the inner cylindrical portion 52 of the dustproof boot 50 holding the rolling bearing 56 freely bends at the folded portion, the irregular motion is allowed smoothly, so that noise such as tapping noise or sliding noise is not generated. The habitability of the vehicle compartment 32 can be improved. Further, the rolling bearing 56 is at least in the engine room 4
Since the seal member 68 is interposed in the annular space on the 0 side, dust and muddy water in the engine room 40 can be rolled in the rolling bearing 5.
6 can be ensured in durability without intruding into the interior of the engine 6, and noise in the engine room 40 can be prevented from entering from the annular space of the rolling bearing 56 into the vehicle interior 32. There is. Further, since the rolling bearing 56 is attached to the holding portion 54 having a U-shaped cross section provided inside the inner cylindrical portion 52 of the dustproof boot 50, the rolling bearing 56 can be easily assembled to the dustproof boot 50, and the vehicle can be easily mounted. It has the advantage of good workability during manufacturing.

Further, by attaching a cover or an auxiliary boot 70 to the outside of the dustproof boot 50 on the passenger compartment side,
The noise transmitted from the engine room 40 to the passenger compartment 32,
In particular, there is the additional advantage that engine noise can be reduced more effectively. The seal member 68 of the rolling bearing 56
Is not limited to the structure illustrated in FIG. 3, and a seal member having another arbitrary structure can be appropriately used as a substitute. Furthermore, in the above-described embodiment, the steering shaft 10 has a two-part structure including the upper steering shaft 14 and the intermediate steering shaft 20, but the intermediate steering shaft 20 may be used if necessary in view of the vehicle layout. It is obvious that the present invention can be applied to the steering shaft 10 having a three-part structure in which a lower steering shaft is further interposed between the steering shaft and the input shaft of the steering gear box 24.

[0016]

As described above, the steering shaft support structure according to the present invention has a steering shaft that penetrates a through hole provided in a toe board with a play gap, and an inner race fitted to the steering shaft. And a rolling bearing having an outer race concentrically arranged on the outer side of the inner race and a rolling member such as a ball interposed between the inner race and the outer race, and one end of the toe board has a through hole peripheral edge. A bearing provided in a portion where the steering shaft penetrates the toe board, the dustproof boot made of a flexible material such as rubber having a second end closely fitted and fixed to the outer portion of the rolling bearing and fixed to the outer portion of the rolling bearing. There is no rattling due to the wear of the device, the steering feeling is excellent, no hammering noise or sliding noise is generated during steering, and therefore the comfort of the vehicle It can be improved, but further achieves an equal variety of effects that can improve the durability of the bearing apparatus.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an entire steering device including a steering shaft support structure according to an embodiment of the present invention.

2 is an enlarged cross-sectional view of the seal and support device 46 in FIG.

3 is an enlarged sectional view of the rolling bearing 56 in FIG.

FIG. 4 is a front view as seen from the direction of arrow IV in FIG.

FIG. 5 is a cross-sectional view of an essential part showing a conventional steering shaft support structure.

[Explanation of symbols]

10 ... Steering shaft, 12 ... Steering wheel, 14 ... Upper steering shaft, 16 and 2
2 ... Hook type universal joint, 20 ... Intermediate steering shaft, 24 ... Steering gear box, 42 ... Toe board, 44 ... Through hole, 46 ... Sealing and supporting device, 50 ... Dustproof boot, 52 ... Inner cylinder part, 54 ... Holding part , 56 ... Rolling bearings.

Claims (4)

[Claims] 1. A steering shaft, which penetrates through holes provided in a toe board with a clearance, an inner race externally fitted to the steering shaft, and an outer race concentrically arranged outside the inner race. A rolling bearing having a rolling member such as a ball interposed between the inner race and the outer race, and one end of which is closely adhered and fixed to the peripheral edge of the through hole of the toe board, and the other end of which is used as an outer race of the rolling bearing. A steering shaft support structure comprising a dustproof boot made of a flexible material such as rubber, which is fitted over the exterior. 2. The outer race of the rolling bearing is closely fitted in an annular groove of a holding portion formed in the other end portion of the dustproof boot and having a U-shaped cross section. The steering shaft support structure according to claim 1. 3. The steering shaft support structure according to claim 1, wherein a dustproof and waterproof seal member is mounted in the annular space of the rolling bearing at least on the outer side of the vehicle compartment. . 4. A small-diameter inner cylinder portion that is folded back and extends outward of the passenger compartment is formed at the other end portion of the dust-proof boot, and the inside cylindrical portion has a U-shaped cross section. The steering shaft support structure according to claim 2, wherein a portion is formed.