JPH0523234B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] <Industrial Application Field> The present invention provides a shock absorbing device for absorbing impact energy applied to the steering wheel at the time of a vehicle collision, at the connection between the steering column and the vehicle body. The present invention relates to a steering tilt device equipped with a steering tilt device.

<Prior art> In order to reduce damage to occupants caused by collisions with the steering wheel due to the impact of a vehicle collision, the steering column including the steering shaft is equipped with a buffer to absorb the impact energy applied in the axial direction. equipment is provided. This kind of impact energy absorption device (hereinafter referred to as "EAU")
JP-A-56-2265 discloses a method in which an energy absorber made of a plastic material is held in a casing made of a substantially rigid body, and the energy absorber is connected to the steering column side.
In addition, the casing is connected to the vehicle body, and when the steering column is displaced in the axial direction due to the axial load applied during a collision, the energy absorber deforms plastically in the elongation direction with respect to the casing, thereby absorbing the impact energy. Devices have been proposed that allow absorption. According to this, the energy absorption characteristic can be set independently, and it can be mounted outside the steering column, so there is an advantage that a high degree of versatility can be obtained.

On the other hand, a steering tilt device is well known for changing the position of the steering wheel to suit the riding posture or physique of the driver. This type of steering tilt device, as disclosed in Japanese Utility Model Application Publication No. 55-85964, is configured such that the fixing part of the steering column to the lower part of the vehicle instrument panel can be moved in the vertical direction, and the steering shaft and steering A typical structure is such that the entire steering column is tilted around a universal joint that connects it to a gearbox, thereby changing the vertical position of the steering wheel.

<Problems to be Solved by the Invention> Incidentally, even with this type of tilt steering device, it goes without saying that it is necessary to have impact mitigation properties in the event of a collision, but the angle at which the steering column is attached to the vehicle body must change. Therefore, it is difficult to provide an external EAU as described above. In many cases, the shock absorbing mechanism had to be built into the steering column, which resulted in inconveniences such as the design of the steering column being complicated and manufacturing costs increasing.

The present invention was made to eliminate such inconveniences, and its main purpose is to provide a structure that allows easy attachment of an external EAU to a tilt type steering device. be.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, the object is to insert and support a steering shaft having a steering wheel fixed to one end and a steering gear connected to the other end. a steering column attached to the vehicle body so as to be tiltable; and a space between the steering column and the vehicle body that extends in the axial direction of the steering column to absorb buffer energy acting in the axial direction of the steering wheel. A steering tilt device with a shock absorber, the shock absorber comprising a substantially rigid body having one end connected to a body bracket for supporting a steering column fixed to a vehicle body. an impact energy absorbing device comprising a casing, and an energy absorber having a portion held by the casing and a portion connected to the steering column, the connection portion of the casing with the body bracket and the steering column of the energy absorber. This is achieved by providing a steering tilt device with a shock absorber characterized in that at least one of the connecting portions with the column has play in the vertical direction. especially,
A vertical elastic force of the casing is applied to the axis of the steering column, and a plate-shaped overhang is provided between the lower surface of the vehicle body and the upper surface of the body bracket at the connection part of the casing to the body bracket, and the overhang is It is best to have a slope that slopes down toward the steering wheel.

<Function> In this way, even if the steering column changes its angle in the vertical direction, the shock absorber can follow the movement of the steering column due to the play of each connecting end. In addition, the vertical elastic force can prevent the casing from rattling, and by slanting the connecting part with the body bracket, the displacement angle of the casing with respect to the distance between the lower surface of the vehicle body and the upper surface of the body bracket can be reduced. It can be relatively large.

<Embodiments> Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

1 to 3 show a tilt-type steering device constructed based on the present invention. As shown in FIG. 1, a steering column 1 having a hollow cylindrical shape has a steering shaft 2 at its axis. is inserted rotatably. A steering wheel 3 is fixed to the upper end of the steering shaft 2, and a steering gear box (not shown) is connected to the lower end via a universal joint 4.

The steering column 1 includes a tilt mechanism 6 that adjusts the angle with respect to the vehicle dash board 5, and an EAU (impact energy absorption device) 7 that absorbs shock from the steering wheel 3 applied in the axial direction, and constitutes the tilt mechanism 6. It is attached to a mount portion 5a on the lower surface of the vehicle body dash board via a column bracket and a body bracket.

As clearly shown in FIG. 2, the steering shaft 2 consists of a top shaft 2a to which the steering wheel 3 is fixed to the upper end, and a lower shaft 2b to which the universal joint 4 is fixed to the bottom end. 2b
The upper end portions each have an oval cross section and fit into each other. The fitting parts are connected to each other via a polyacetal shear pin (not shown), and when a predetermined axial impact load is applied to the steering shaft 2, this shear pin is sheared and the upper shaft 2a is connected to the lower shaft 2b. The entire length of the steering shaft 2 is reduced.

On the other hand, the steering column 1 consists of an upper tube 1a and a lower tube 1b that are connected via a number of steel balls (not shown) press-fitted between the fitting portions of each other, and usually have a predetermined axial dimension. However, when a predetermined axial load is applied to the steering column 1, the contact portions with the steel balls deform and slide relative to each other. The upper shaft 2a is supported by the upper tube 1a, and the lower shaft 2b is supported by the lower tube 1b so as not to be displaced in the axial direction.

A column bracket 8 consisting of a pair of plates 8a spaced apart from each other at a predetermined distance in the width direction of the vehicle body and a shaft 8b connecting the inner surfaces of these plates 8a is fixed to the upper outer periphery of the attachment tube 1a of the steering column 1. ing. The outer surface of this column bracket 8 is held between a pair of body brackets 9 for fixing the steering column 1 to a mount portion 5a on the lower surface of a vehicle dash board.

The body bracket 9 consists of a pair of left-right symmetrical shapes curved from plate material, and the column bracket 8
The hanging part 9a that holds the
b. As shown in FIG. 3, the horizontal portion 9b is formed with a U-shaped slot 10 that opens toward the steering wheel 3.
Two small holes 11 are bored on each side of this slot 10. A slide plate 12 made of polyacetal is insert-molded through the slot 10 and the small hole 11 so as to sandwich the horizontal portion 9b from both upper and lower surfaces thereof. This results in
The portion through the small hole 11 serves as a shear pin that connects the horizontal portion 9b and the slide plate 12. In addition, an appropriate space is provided between the center of the upper surface of the slide plate 12 and the mount portion 5a on the lower surface of the vehicle body dash board.
A spacer boss 13 is provided so as to protrude so as to leave the spacer.

A bolt hole 14 is bored in the center of the connecting shaft 8b of the column bracket 8, passing through both the left and right sides. Furthermore, vertically elongated holes 15 having a partially arcuate shape are formed in both body brackets 9 at positions aligned with the bolt holes 14. And these long holes 1 in both body brackets 9
5 and the clamp bolt 16 is inserted coaxially into the bolt hole 14 of the connecting shaft 8b, and the clamp bolt 1 protrudes from the hanging portion 9a of one body bracket 9.
The column bracket 8 and the body bracket 9 can be fastened to each other by screwing and tightening the threaded portion 18 of the operating lever 17 onto the end of the column bracket 6.

The EAU 7 is provided on the upper surface side of the uppipe tube 1a of the steering column 1. This EAU 7 includes a hollow box-shaped casing 19 with both front and rear (left and right in the figure) open end faces, and an energy absorber 20 housed within the casing 19.
It is made up of. The energy absorber 20 is a third
As shown in the figure, a single wire with both ends curved in a U-shape is folded back at the center, and each curved portion 21
The tips of a and 21b are free ends, and the casing 1
Its shape is defined by the inner surface of the side wall 9. Both of these curved parts 21a and 21b are inserted into the casing 19 while being covered with a rubber cover 22, so that the casing 19
and the energy absorber 20 can be relatively displaced along the axial direction of the steering column 1 without metal contact. Further, a boss 25 protruding from the central portion 23 folded back into a loop shape and an island 24 formed on the upper surface of the uppipe tube is inserted. A rubber spacer 26 is fixed to this boss 25, and a nut 27 is screwed onto the upper end of the spacer 26, thereby allowing the energy absorber 2
The center portion 23 of the 0 is prevented from slipping out upward from the boss 25.

A pair of stopper pins 28 are provided in the casing 19 so that the free ends of the curved portions 21a and 21b come into contact with each other when the energy absorber 20 and the casing 19 are relatively displaced in the extension direction. These left and right stopper pins 28 are arranged in parallel at substantially the same position in the axial direction. On the other hand, regarding the axial positions of both curved portions 21a and 21b in the energy absorber 20, the curved portion 21a located on the right side when viewed from the steering wheel side protrudes more toward the steering wheel side,
Along with this, the distance between each free end of both curved parts 21a, 21b and the stopper pin 28 is also wider for the one 21a located on the right side.

At the end of the casing 19 of the EAU 7 on the steering wheel side, projecting parts 29 are formed in both left and right directions along the horizontal part 9b of the body bracket 9. An engagement hole 30 is formed in the center of both of the projecting portions 29, through which a spacer boss 13 protruding from the slide plate 12 of the body bracket 9 is loosely inserted. In addition, hooks 31 are protruded from both the left and right ends of the casing 19 on the side of the universal joint, and a spring receiver 32 is fixed to the lower surface of the attachment tube 1a.
The EAU 7 is always elastically biased downward by the tension coil spring 33 stretched between the EAU 7 and the tension coil spring 33 .

In the tilt-type steering device configured in this way, a fixing bolt 35 is inserted into a bolt hole 34 drilled through the spacer boss 13 in the center of the slide plate 12, and the fixing bolt 35 is inserted into the mounting portion of the vehicle dash board. 5a, it is fixed to the vehicle body via the attachment tube 1a of the steering column 1. The lower tube 1b is fixed to the vehicle body via a jacket tube bracket (not shown).

Next, the operation of the above embodiment will be explained.

As described above, the body bracket 9 is fixed to the mount portion 5a of the vehicle body with the fixing bolt 35 inserted through the horizontal portion 9b, and the body bracket 9 and the column bracket 8 are connected via the clamp bolt 16. Therefore, the coupling force of the column bracket 8 to the body bracket 9 is determined exclusively by the tightening torque of the clamp bolt 16.
This tightening torque is determined by tightening or loosening the operating lever 17. That is, when the operating lever 17 is rotated in the loosening direction, the steering column 1 can be tilted vertically within the range of the elongated hole 15 in the body bracket 9, thereby changing the vertical position of the steering wheel 3. It will be done.

Then, by rotating the operating lever 17 in the tightening direction at an appropriate position, the position of the steering column 1 is fixed. Note that a tension coil spring 36 is provided between the operating lever 17 and the column bracket 8 to constantly bias the operating lever 17 in a tightening direction, so as to improve the operability of the operating lever 17. is being used. At the same time, a projecting piece 37 that abuts the upper surface of the operating lever 17 is provided to protrude from the plate 8a of the column bracket 8 to prevent the operating lever 17 from rotating more than necessary. Moreover, between the horizontal part 9a of the body bracket 9 and the lower part of the column bracket 8,
Balance spring 3 that balances the weight of the steering device
7 is stretched to prevent the steering column 1 from falling suddenly when the operating lever 17 is loosened.

By the way, since the upper shaft 2a and the lower shaft 2b are connected via the shear pin, and the horizontal part 9a of the body bracket 9 and the mount part 5a of the vehicle body are connected via the shear pin part of the slide plate 12 and the fixing bolt 35, Under the normal operating load, the relative movement of the upper tube 1a and the lower tube 1b in the axial direction is defined, and at the same time, the position of the body bracket 9 with respect to the vehicle body mount portion 5a is also defined. Therefore, the rotational force applied to the steering wheel 3 is transmitted to the steering gear box via the steering shaft 2 and the universal joint 4.

When a driver collides with the steering wheel 3 due to a vehicle collision or the like, the shear pin between the upper shaft 2a and the lower shaft 2b is cut due to the impact load at this time, and both shafts 2a and 2b are relatively displaced in the direction of contraction. At the same time, this impact load is also transmitted to the body bracket 9 via the column bracket 8 fixed to the attachment tube 1a, and also cuts the shear pin portion of the slide plate 12. In this part, since the fixing bolt 35 is inserted into the slot 10 of the horizontal part 9b of the body bracket 9, only the horizontal part 9b falls off from the fixing bolt 35 forward. Thereby, the attachment tube 1a can also be moved forward.

During this time, a portion of the impact energy is absorbed by the cutting of each shear pin.

When the upper tube 1a starts to move forward, the steel balls between the upper tube 1a and the lower tube 1b deform and displace the fitting surfaces relative to each other, and this deformation further absorbs a portion of the impact energy. On the other hand, since the fixing bolt 35 remains on the vehicle body mount part 5a, when the attachment tube 1a moves forward, the energy absorber 20 connected to the attachment tube 1a and the casing 19 connected to the fixation bolt 35 are separated. will undergo a relative displacement. As a result, the free end of the left curved portion 21b first hits the corresponding stopper pin 28. Then, the axial movement of the free end of the curved portion is restricted, so that the central portion 2
3, the curved portion 21b deforms while being continuously shifted one after another, and the impact energy is further absorbed. Next, when the free end of the right curved portion 21a comes into contact with the corresponding stopper pin 28, these sides 21a
is deformed in the same way, and the impact energy is absorbed.

In this way, as the upper tube 1a moves forward, the steel ball, the left curved portion 21b, and the sea pin between the upper tube 1a and the lower tube 1b.
The right curved portion 21a is activated in this order, and the resistance force thereof increases sequentially in accordance with the amount of axial displacement of the steering column 1. Therefore, depending on the magnitude and duration of the impact when the driver collides with the steering wheel 3, the buffering effect works more accurately, and the reaction force applied to the occupant can be suppressed to the minimum.

Now, since the EAU 7 of the above type can be designed separately from the steering column 1, extremely high versatility can be obtained. However, on the other hand, since it is necessary to connect one end to the steering column 1 and the other end to the car body dart board 5, one point is that it must be made to follow the tilting of the steering column 1 when attached to a tilt type steering device. It was becoming an obstacle. Therefore, in the present invention, both connecting ends of the EAU 7 are provided with play in the vertical direction as shown by dimensions A and B in FIG. By doing so, it is possible to prevent the EAU 7 from interfering with the tilting operation of the steering column 1.

Furthermore, the distance between the horizontal part 9a of the body bracket 9 and the lower surface of the vehicle body mount part 5a is emphasized and shown widely in FIG. It is preferable to be as narrow as possible in order to increase the rigidity of the So the second
As shown at angle C in the figure, the overhanging portion 29 of the casing 19 is bent so that the steering wheel side is directed somewhat downward. By doing this, as shown by comparison in FIGS. 4 and 5, the tilting angle from the position approximately parallel to the steering column 1 is the same as 〓(D dimension)
If it is within, it is assumed that a larger angle (I1<I2) can be displaced.

In addition, play in the connecting parts (A and B in Figure 2)
In order to prevent the EAU 7 from vibrating due to the size), a tension coil spring 33 is stretched between the casing 19 and the attachment tube 1a.

On the other hand, in such a tilt-type steering device, the operating lever 17 tends to be located close to the driver's knees, but when the driver moves left or right in the event of a side collision, etc., the operating lever 17
There is a risk that your knee will hit the ground. This operating lever 17
has relatively high rigidity, and therefore the reaction force on the knee in the event of a collision is large, and is thought to cause relatively large damage. Therefore, in this embodiment, as shown in FIGS. 6 to 8, a bulge 41 that can be deformed when the knee bumps is provided on the lower side of the pivot, which has particularly high rigidity. .

The impact absorbing surface of this bulge 41 is provided with an opening 42 of an appropriate area, and a crease 43 is formed by pressing. In this way, the deformation strength and directionality are adjusted, and the impact absorption properties are stabilized. Further, the bulging portion 41 forms a hollow portion 45 by joining a main portion 41a made of a relatively thick plate and a subordinate portion 41b serving as an impact dispersion member made of a thin plate. By doing this, the subordinate part 4
1b serves as a cover that smoothly covers the shock absorbing surface side of the operating lever 17, and the slave portion 41b
The main part 41a and the main part 41a deform sequentially to absorb the impact in stages, thereby alleviating the reaction force caused by the collision from being suddenly applied to the knee part.

Although the edge 44 of the subordinate part 41b is bent toward the main part 41a, this bending angle is obtuse as shown in FIG.
Regularity is given to the direction in which this end edge 44 deforms when it hits the main portion 41a. By stretching this bent portion 46, a portion of the impact load is absorbed. Further, the shock absorption characteristics can be adjusted not only by the bent portion 46, but also by interposing a compressible resin material or the like between the main portion 41a and the subordinate portion 41b.

On the other hand, in the above-mentioned tilt type steering device, a spring means is usually provided in order to balance the weight of the steering device applied downward during an adjustment operation. However, in order to simplify parts management and reduce assembly man-hours, it is preferable to promote subassembly within a range where the handling weight does not exceed a certain limit. However, in the above structure, the tension of the balance spring 37 causes the body bracket 9 to rotate about the clamp bolt 16, resulting in a large deviation between the angle of the horizontal portion 9b and the angle of the mount portion 5a. Sometimes it happens. Therefore, in this embodiment, a locking piece 5 that locks each other is provided between the column bracket 8 and the body bracket 9.
1 and 52, respectively, to prevent rotation of the body bracket 9 due to spring tension.

The structure to prevent this rotation is as follows:
A locking piece 53 is attached to the front end of the casing 19 of EAU7.
is provided, and this and the horizontal part 9b of the body bracket 9
The space between the island 24 provided in the uppipe tube 1a and the horizontal portion 9b of the body bracket 9 may be stretched by the projecting portion 29 engaged with the spacer boss 13 projecting from the top tube 1a. In addition, in this case, from the spacer boss 13 upward
To prevent EAU7 from coming off,
It is even better if the locking pawl 54 is provided so that the body bracket 9 and the horizontal portion 9a of the body bracket 9 lock with each other.

[Effects of the Invention] As described above, according to the present invention, since an external EAU device can be attached to the steering tilt device, its buffering performance can be easily improved, and moreover, the standardization of parts can be promoted. Because it is possible,
This is effective in reducing manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a schematic overall side view of a tilt type steering device constructed based on the present invention. FIG. 2 is an enlarged side view with a portion cut away, and FIG. 3 is an enlarged plan view. FIG. 4 is a schematic diagram showing the displacement of the connecting portion of the EAU with the vehicle body without any countermeasures taken, and FIG. 5 is a schematic diagram similar to FIG. 4 but with the countermeasures taken. FIG. 6 is a partially enlarged view of the tilt operating lever, FIG. 7 is a view taken in the direction of arrows in FIG. 6, and FIG. 8 is a partial sectional view taken along the - line. 1... Steering column, 1a... Atsupati tube, 1b... Lower tube, 2... Steering shaft, 2a... Atsupashi shaft, 2b...
...lower shaft, 3...steering wheel,
4...Universal joint, 5...Car body dart board, 5
a...Mount section, 6...Tilt mechanism, 7...
EAU, 8...Column bracket, 8a...Plate material,
8b...Connection shaft, 9...Body bracket, 9a
...Drooping part, 9b...Horizontal part, 10...Slot, 11...Small hole, 12...Slide plate,
13... Spacer boss, 14... Bolt hole, 15
... Long hole, 16 ... Clamp bolt, 17 ... Operation lever, 18 ... Threaded part, 19 ... Casing, 20 ... Energy absorber, 21a, 21b ...
...Curved part, 22...Cover, 23...Central part, 2
4...Island, 25...Boss, 26...Spacer, 27...Natsuto, 28...Stoppin,
29... Overhanging portion, 30... Engaging hole, 31... Hook, 32... Spring receiver, 33... Tension coil spring, 34... Bolt hole, 35... Fixing bolt,
36...Tension coil spring, 37...Balance spring, 41...Bulging part, 41a...Main part, 41b...
...Subordinate part, 42...Opening, 43...Fold, 44...
...Edge, 45...Hollow part, 46...Bent part, 51
~53... Locking piece, 54... Locking claw.

Claims (1)

[Scope of Claims] 1. A steering column that inserts and supports a steering shaft having a steering wheel fixed to one end and a steering gear connected to the other end and is tiltably attached to a vehicle body, and an axial direction of the steering column. a steering tilt device with a shock absorber, comprising a shock absorber connected between the steering column and the vehicle body to absorb impact energy acting in the axial direction of the steering wheel by extending the steering column; The shock absorber includes a substantially rigid casing whose one end is connected to a steering column supporting body bracket fixed to the vehicle body, and a portion held by the casing and connected to the steering column. an impact energy absorbing device comprising an energy absorbing body having a portion having a radial shape, at least one of a connecting portion of the casing with the body bracket and a connecting portion of the energy absorbing body with the steering column,
A steering tilt device with a shock absorbing device characterized by having vertical play. 2. The steering tilt device with a shock absorbing device according to claim 1, wherein a resilient biasing means in the vertical direction is interposed between the casing and the steering column. 3. The connecting portion of the casing to the body bracket is comprised of a plate-shaped projecting portion sandwiched between the lower surface of the vehicle body and the upper surface of the body bracket, and the projecting portion is sloped downward toward the steering wheel. A steering tilt device with a shock absorber according to claim 1 or 2, wherein the steering tilt device has a shock absorbing device.