JPH09267756A - Steering structure for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the sufficient displacement of a steering gear box backward, to prevent the application of a large bending force to a steering shaft and to position a steering wheel in a low position at the time of clashing in front. SOLUTION: A steering shaft 1 is connected to a steering gear box 5 by an intermediate shaft 3. The shaft 1 is held so as to be freely swung to a car body in a rear side more than its connecting part 4 with the intermediate shaft 3 and around a swing fulcrum Y positioned higher than the shaft 1 within the range of a long hole extending in upper and lower directions. By a lock releasing mechanism R lock-released upon receiving an external force more than a specified level, the swinging of the shaft 1 is usually locked. At the time of clashing in front, the gear box 5 is displaced backward and upward and interferes with the point K of the intermediate shaft 3, but an upward divided force is applied to the front end part of the shaft 1 by the interference and thus the shaft 1 is swung around the fulcrum Y in a direction for displacing a steering wheel 2 downward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle steering structure.

[0002]

2. Description of the Related Art A steering shaft of a vehicle is generally provided with a steering handle at its rear end, and its front end is generally connected to a steering gear box through an intermediate shaft. This steering gear box is usually arranged in a power plant, which is arranged in the engine room formed in the front of the passenger compartment, particularly in the vicinity of the transmission, but may be located higher than the transmission. Many.

In the above-mentioned setting of the arrangement position of the steering gear box, the transmission (casing thereof) and the steering gear box are substantially circular when viewed from the side. Then, the transmission, which is a large heavy object, is set so as to move downward and backward during a frontal collision, and therefore the steering gear box is inevitably displaced upward and rearward during a frontal collision.

When the steering gear box is displaced rearward and upward, when the connecting portion between the steering shaft and the intermediate shaft is used as a specific connecting portion, the intermediate shaft is downward and rearward with respect to this specific connecting portion. It will try to be swung toward.

[0005]

When the steering gear box is displaced rearward and upward to some extent, the specific connection portion and the steering gear box interfere with each other,
The rearward swing of the intermediate shaft, that is, the further rearward displacement of the steering gear box is hindered. In order to obtain the rearward displacement of the steering gear box after such interference, the specific connecting portion must be displaced upward, but the upward displacement of the specific connecting portion causes the steering shaft to move. It is necessary to avoid the situation where a large bending force acts.

On the other hand, at the time of a frontal collision, it is desired to keep the steering wheel in a position as low as possible in consideration of a secondary collision in which an occupant contacts the steering wheel.

The present invention has been made in consideration of the above circumstances, and an object thereof is to secure a sufficient rearward displacement of the steering gear box and to exert a large bending force on the steering shaft at the time of a frontal collision. To prevent
(EN) It is an object of the present invention to provide a steering structure for a vehicle that can satisfy the requirements of keeping the steering wheel in a position as low as possible.

In order to achieve the above object, the present invention has the following structure. That is, the front end of the steering shaft is connected to the steering gear box via the intermediate shaft, and the steering shaft and the intermediate shaft, and the intermediate shaft and the steering gear box are connected by swingable connecting members. In the steering structure, a steering shaft is supported by a vehicle body so as to be vertically swingable within a predetermined range around a predetermined swing center, locks the swing of the steering shaft, and receives an external force of a predetermined amount or more. A lock mechanism for releasing the lock function is provided, and the rear end portion of the steering shaft moves downward around the swing center in response to a predetermined upward or rearward displacement of the steering gear box at the time of a frontal collision. The swing center position is set so that it is displaced. That, some such as configuration. Preferred embodiments based on the above configuration are as described in claims 2 and 3 in the claims.

According to the above construction, the specific connecting portion, which is a connecting portion between the steering shaft and the intermediate shaft, interferes with the steering gear box when the steering gear box is displaced upward and backward by a predetermined amount or more. . In this interference state, the specific connecting portion receives an upward force from the steering gear box, and the swing force input portion that displaces the rear end portion of the steering shaft about the predetermined swing center, that is, the handle mounting side downward. Becomes Then, the steering shaft which receives this swinging force is swung so that the handle mounting side is displaced downward without being bent. Further, the specific coupling portion is easily displaced upward, that is, escaped, whereby the steering gear box is released from the interference with the specific coupling portion and can be displaced further rearward.

[0010]

According to the first aspect of the present invention, in the case of a frontal collision, the steering gear box is displaced further rearward, the steering shaft is prevented from being bent, and the steering handle is lowered. You can satisfy all of the above.

With the structure as described in claim 2, it is possible to obtain the effect corresponding to claim 1 by effectively utilizing the tilt mechanism which is generally used conventionally as it is.

By adopting the structure as described in claim 3, the steering handle can be set to a sufficiently low position.

With the structure as described in claim 4, it is possible to provide a more specific structure for ensuring the vertical swing of the steering shaft and the lock mechanism. Particularly, since the conventional tilt mechanism has the first bracket, the second bracket, the long hole, and the bolt,
These can be effectively used as they are.

With the structure as described in claim 5, the lock utilizing frictional engagement allows the lock to be easily released when a large external force at the time of a frontal collision is received, The corresponding effect can be surely obtained.

With the structure as described in claim 6, when the steering handle is in the vertical intermediate position, the handle can be further lowered in the event of a frontal collision.

The structure as described in claim 7 is preferable in order to sufficiently secure the rearward displacement of the steering gear box.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In FIG. 1, reference numeral 1 denotes a steering shaft (inner shaft), which is arranged so as to incline so as to be gradually positioned downward as it extends forward, and its rear end located on the vehicle compartment A side. A steering handle 2 is attached to the portion 1a. The front end 1b of the steering shaft 1 is connected to the rear end of the intermediate shaft 3 via a universal joint 4. A front end portion of the intermediate shaft 3 is connected to a steering gear box 5 arranged in the engine room B via a universal joint 6. Reference numeral 7 in the drawing is a toe board that separates the vehicle compartment A from the engine room B. The universal joints 4 and 6 constitute a swingable connecting member.

The gear box 5 is arranged near the transmission 8 arranged in the engine room B. Transmission 8
Is a power plant together with an engine and a clutch (or a torque converter) which are not shown in the figure, and extends in the left-right direction of the vehicle body. The transmission 8 (power plant) is attached to the vehicle body frame so as to be displaced rearward and downward during a frontal collision. The gearbox 5 is located rearward and high above the transmission 8, so that when the transmission 8 is displaced rearward and downward, the arrow α
As shown, it is displaced rearward and upward.

The intermediate shaft 3 is composed of a front shaft 3a and a rear shaft 3b which are divided into two parts in the axial direction. (Not shown) are connected so as not to be displaced relative to each other in the axial direction.
Then, the pin is broken when an external force of a predetermined amount or more is received in the axial direction so that the intermediate shaft 3 can be shortened (Coplas mechanism).

The steering shaft 1 is rotatably held in an outer cylinder 21 (outer shaft). Also,
Similar to the intermediate shaft 3, the steering shaft 1 can be shortened when a large external force in the axial direction equal to or more than a predetermined value is applied (a two-part configuration of 1a side and 1b side,
With Copras mechanism). The rear portion 1b of the steering shaft 1 is held so as not to be displaced axially relative to the outer cylinder 21, while the front portion 1a is held.
Is held so as to be displaceable in the axial direction relative to the outer cylinder 21 (when the steering shaft 1 is co-loaded).

The steering shaft 1 is held on the vehicle body as follows. First, a vehicle body side bracket (first bracket) 12 is fixed to a steering support member 11 as a strength member extending in the vehicle body left-right direction. A front bracket 13 is attached to the front end of the vehicle body bracket 12, and a rear bracket 14 is attached to the rear end of the vehicle body bracket 12.
The steering shaft 1 is held by the front and rear brackets 13 and 14 via an outer cylinder 21 (outer shaft).

The steering shaft 1 includes the outer cylinder 21.
It is held by the front and rear brackets 13 and 14 via. The outer cylinder 21 is held by the front bracket 13 so that the outer cylinder 21 can slide in the axial direction and can swing. That is, as shown in FIG. 3, the outer cylinder 21 is slidably covered by the front bracket 13 from below, and the upper end portion of the front bracket 13 is arranged in the left-right direction with respect to the front end portion of the lower bracket 12. It is rotatably connected by an extending rocking axis Y.
The swing axis Y serves as a swing fulcrum in a tilt mechanism described later, and is located rearward and upward of the universal joint 4.

The outer cylinder 21 is held by the rear bracket 14 so that the outer cylinder 21, that is, the steering shaft 1 can swing about the swinging fulcrum Y for a predetermined amount, and a desired swinging, as described later. It is designed so that it can be locked in the moving position.

A holding structure for the outer cylinder 21 using the rear bracket 14 will be described with reference to FIG. First,
The rear bracket 14 is formed by bending an iron plate, for example, and a pair of vertical wall portions 14a formed to sandwich the outer cylinder 21 and a bottom wall portion 14b connecting the lower end portions of the vertical wall portions 14a to each other. And a pair of left and right flange portions 14c extending in directions away from each other from the upper ends of the vertical wall portions 14a.

An intermediate bracket 22 formed by bending an iron plate, for example, is welded to the lower end of the outer cylinder 21 between the pair of left and right vertical wall portions 14a. A bolt 23 penetrates the intermediate bracket 22, while a long hole 24 through which the bolt 23 penetrates is formed in the vertical wall portion 14a. The elongated hole 24 extends in the vertical direction and is formed in an arc shape centered on the swing fulcrum Y.

A bolt 23 protruding outside the vertical wall portion 14a
At one end of the lock nut 26 through the friction element 25
An operating arm 27 that is manually operated by the driver is integrated with the lock nut 26. A lock mechanism R is configured by the members 23 to 27.

The lock nut 2 is operated by operating the operation arm 27.
By loosening 6, the outer cylinder 21, that is, the steering shaft 1 is swung (tilted) about the swing fulcrum Y in the range of the elongated hole 24. Then, at the desired swing position (tilt), the operation arm 27 is operated to tighten the lock nut 26, whereby the outer cylinder 21, that is, the steering shaft 1 is locked at the desired swing position.

The vehicle body side bracket 12 is formed with a pair of left and right flange portions 12a that abut against the flange portion 14c of the rear side bracket 14, and a bolt 15 is formed between the flange portions 12a and 14c. Has been concluded (see also Fig. 4). The bolt 15 is designed to be broken when an external force of a predetermined amount or more is received in the axial direction of the steering shaft 1, so that when an external force of a predetermined amount or more is received from the handle 2 side, the outer cylinder 21 is broken.
That is, the steering shaft 1 is mounted on the vehicle body side bracket 1.
The front bracket 13 holds the outer cylinder 21 slidably in the axial direction.

A central connecting portion 12b is formed to connect the pair of left and right flange portions 12a. The central connecting portion 12b covers the outer cylinder 12 from above. The central connecting portion 12b has a rising portion 12c that extends in the vertical direction in the vicinity of the connecting portion with the flange portion 12a.

A key cylinder (for ignition switch) mounting bracket 41 as a guided member is fixed to a portion of the outer cylinder 21 located slightly rearward of the vehicle body side bracket 12. As shown in FIG. 5, the mounting bracket 41 has a divided configuration of an upper bracket 41a and a lower bracket 41b holding a key cylinder, and both brackets 41a and 41b cover the outer cylinder 21. In this state, they are connected by bolts 44 (tightened and fixed to the outer cylinder 21).

Guide portions 42 and 43 are formed on the inner surface of the central connecting portion 12b of the vehicle body side bracket 12 so as to correspond to the mounting bracket 41 (upper bracket 41a). The guide portions 42 are formed on the inner surface of each of the rising portions 12c and have a pair of left and right sides. The rear end of the guide portion 42 is formed to be slightly larger than the left and right width of the mounting bracket 41, and the distance between the pair of left and right guide portions 42 is gradually reduced toward the front.
From the middle thereof, it is set to be smaller than the left and right width of the mounting bracket 41 by a predetermined amount.

As a result, when the mounting bracket 41 is displaced forward relative to the vehicle body side bracket 12 due to a secondary collision, the mounting bracket 41 is guided by the guide portion 42 and the steering shaft 1 is moved in the left-right direction. Arbitrary movements are restricted. Then, the mounting bracket 41 is forcibly deformed so as to widen the interval between the pair of left and right guide portions 42, whereby the impact of the secondary collision is absorbed.

On the other hand, the rear end of the guide portion 43 is slightly higher than the mounting bracket 42 in the radial direction of the steering shaft 1, but gradually approaches the axis of the steering shaft 1 as it goes forward. Thus, the height is lower than the height of the mounting bracket 42 from the middle.

As a result, when the mounting bracket 41 is displaced forward relative to the vehicle body side bracket 12 due to the secondary collision, the mounting bracket 41 is guided by the guide portion 43 and the steering shaft 1 is moved upward. Movements are regulated. And the mounting bracket 41
By forcibly deforming the guide portion 43 so as to crush it, the impact of the secondary collision is absorbed.

As described above, the vehicle body side bracket 12 is formed with the concave portion 40 (the guide hole serving as a fitting cavity) into which the bracket 41 is fitted at the time of the secondary collision. The left and right inner surfaces of the guide portion 42
The upper inner surface of the recess 40 is formed as the guide portion 43. Each of the guide portions 42 and 43 expands a part of the vehicle body side bracket 12 so that the guide portions 42 and 43 are formed so that the guide portions 42 and 43 are easily guided and deformed by receiving the contact force from the bracket 41. It is preferable that the guide portions 42 and 43 are formed by being deformed so as to be deformed (the thickness of the guide portions 42 and 43 is not so thick as compared with the thickness of the vehicle body side bracket 12).

Referring again to FIG. 1, consider a frontal collision.
At this time, as described above, the steering gear box 5
Is displaced rearward and upward as indicated by arrow α. According to the rearward and upward displacement of the steering gear box 5, the intermediate shaft 3 is contracted by the co-plus (the front shaft 3a is displaced rearward), and the tip end thereof is, as shown by an arrow β, a universal joint 4 It is swung downward and rearward about the center. The point K where the arrows α and β first intersect is the position where (the line end portion of) the intermediate shaft 3 and the steering gear box 5 interfere with each other.

After the interference at point K, the upward and rearward displacement force of the steering gear box 5 pushes the steering shaft 1 (universal joint 4) rearward via the intermediate shaft 3. Force and a component force that displaces the front end portion of the steering shaft 1 upward. The upward component force is a swinging force in the direction in which the steering wheel 1 displaces the steering shaft 1 downward about the swinging fulcrum Y, but the upward component force is due to a frontal collision and is considerably large. Due to this, the lock of the lock mechanism R is released, and the steering shaft 1 swings so that the handlebar 2 is displaced downward (displacement of the steering gear box 5 from point K to point c).

Since the swing fulcrum Y is located at a position higher than the axis of the steering shaft 1, the swing fulcrum is set at a position on the axis of the steering shaft 1 indicated by, for example, δ, The handle 2 can be displaced further downward. The bending rigidity of the steering shaft 1 is stronger than the lock force of the lock mechanism R.

When the steering gear box 5 is displaced rearward and upward beyond point c, the steering shaft 1 is swung so as to displace the handle 2 upward about the swing fulcrum Y. However, at this stage, the tip ends of the steering gear box 5 and the intermediate shaft 3 are in a state of being displaced rearward of the universal joint 4 (up to point f at which α and β again intersect).

When the steering gear box 5 is further displaced rearward and upward from point f (up to point g), the intermediate shaft 3 is swung rearward while extending around the universal joint 4.

Although the embodiments have been described above, the present invention is not limited to this, and includes, for example, the following cases. It does not need to have a tilt mechanism. In this case,
The inclination angle of the steering shaft 1 is always constant, and the steering wheel 2 is swung so as to be displaced downward during a frontal collision.

When the steering shaft 1 is held at a predetermined swing angle, for example, a gear (contact between projections) may be used instead of frictional fastening, and in this case, an external force of a predetermined value or more is applied. When applied, the gear (projection) may be easily broken (for example, formed of synthetic resin) to allow the swing of the steering shaft 1.

The swing center Y of the steering shaft 1 is
If it is possible to secure the swinging such that the handle 2 is displaced downward when an upward force is applied to the front end portion of the steering shaft 1 such as when it is formed on the axis of the steering shaft 1, the steering shaft 1 is set at an appropriate position. can do. Of course, the elongated hole 24 may be formed on the bracket 22 side.

[Brief description of drawings]

FIG. 1 is a side view showing one embodiment of the present invention.

FIG. 2 is a detailed view of a portion of a rear bracket that holds a steering shaft on a vehicle body side, and is taken along line X2-X2 in FIG.
A sectional view corresponding to a line.

FIG. 3 is a cross-sectional view taken along line X3-X3 of FIG. 1, showing a portion of the front bracket that holds the steering shaft on the vehicle body side.

FIG. 4 is a plan view showing a holding portion of a steering shaft by a rear bracket when the rear bracket is viewed from above.

5 is a cross-sectional view taken along line X5-X5 in FIG. 1, showing a key cylinder mounting bracket as a guided member provided on the outer cylinder of the steering shaft.

FIG. 6 is a partial cross-sectional plan view showing a relationship between a guide portion provided on a vehicle body side bracket and a key cylinder mounting bracket as a guided member.

[Explanation of symbols]

 1: Steering shaft 2: Handle 3: Intermediate shaft 4: Universal joint 5: Steering gear box 8: Transmission 11: Steering support member 12: Body side bracket 13: Front side bracket 14: Rear side bracket (first bracket) 22: Intermediate bracket (second bracket) 23: Bolt 24: Long hole 25: Friction element 26: Lock nut 27: Operating arm α: Steering gear box displacement direction β: Intermediate shaft displacement direction K: Interference point Y: Steering shaft displacement Swing fulcrum R: Lock mechanism

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Sugamoto 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Motor Corporation

Claims (7)

[Claims] 1. A front end portion of a steering shaft is connected to a steering gear box via an intermediate shaft, and a steering shaft and an intermediate shaft, and an intermediate shaft and a steering gear box are respectively connected by swingable connecting members. In a vehicle steering structure, a steering shaft is supported by a vehicle body so as to be vertically swingable in a predetermined range around a predetermined swing center, locks the swing of the steering shaft, and receives an external force of a predetermined amount or more. And a rear end portion of the steering shaft centering around the swing center in response to a displacement of the steering gear box upward and backward by a predetermined amount or more at the time of a frontal collision. The swing center position is set so that the Steering structure of the vehicle by which, it is characterized. 2. The steering structure for a vehicle according to claim 1, wherein the swing center and the lock mechanism are set for tilt adjustment of a steering shaft. 3. The swing center according to claim 1, wherein the swing center is set rearward of a connecting portion between the intermediate shaft and a steering shaft and above a shaft line of the steering shaft. A steering structure for a vehicle, which is characterized in that 4. The steering shaft according to claim 1, wherein the steering shaft is provided with a second bracket provided on the steering shaft side with respect to a first bracket provided on the vehicle body side support member. A long hole extending vertically is formed in one of the first bracket and the second bracket, and a bolt penetrating the long hole is provided in the other of the first bracket and the second bracket. A steering structure for a vehicle, characterized in that the steering shaft is set so as to swing in the vertical direction according to the movement of the bolt in the elongated hole. 5. The vehicle steering structure according to claim 4, wherein the lock mechanism is configured to frictionally fasten the first bracket and the second bracket using the bolt. . 6. The rear end portion of the steering shaft according to claim 4, wherein the rear end portion of the steering shaft can be displaced downward during a frontal collision in a state where the bolt is located at a substantially intermediate position in the vertical direction of the elongated hole. The steering structure of the vehicle, which is characterized in that 7. The steering gear box according to claim 1, wherein the steering gear box is displaceable rearward of a connecting portion between the steering shaft and the intermediate shaft during a frontal collision. A steering structure for a vehicle characterized by the following.