JPH08133103A - Steering gear box supporter - Google Patents

Abstract

PURPOSE: To carry out the coexistence of vibration absorption and steering stability in the axial direction of a gear box by retaining by means of a vehicle body fitting portion and a tightening bracket a grommet to be inserted into the steering gear box, providing at the grommet plural elastic members whose spring constants are mutually different axially. CONSTITUTION: A pipelike grommet 12 formed of a single elastic material is fittingly furnished to the outer periphery surface of the gear housing 10 of the gear box of a steering device, and on both sides of the grommet 12, flange portions 14L, 14R are formed integrally. As for the gear housing 10, both side portions and the lower portion of it are of a plane shape, and its upper portion is made to be the shape of a semicircle arc, and the grommet 12 is retained by means of a vehicle body fitting portion 16 on the lower side of the gear housing 10 and a tightening bracket 18 fitted to the fitting portion 16. Also, low hardness elastic members 36 between the deep groove 28 of an elastic body retaining cover 24 and a U shaped portion 18A, slide plates 34 on a shallow groove 26 side, and in addition high hardness elastic members 32 at the shallow groove 26, are respectively arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering gear box supporting device in a steering device of an automobile.

[0002]

2. Description of the Related Art For example, as shown in Japanese Utility Model Laid-Open No. 59-186173, a steering gear box of an automobile is supported on a vehicle body by a bracket, and a steering wheel is provided between the steering gear box and the bracket. A grommet formed of an elastic body such as rubber is provided to absorb the vibration of the gear box.

By the way, in a vehicle equipped with a power steering device for assisting the steering force by hydraulic pressure or the like, a goo sound (abnormal sound), which is one of the abnormal sounds of the steering system.
There is a problem that occurs. This is because the gearbox of the power steering vibrates due to the pulsation of hydraulic pressure, and the vibration is transmitted to the vehicle body and is generated in the vehicle interior. One of the methods for solving this gooing noise is to reduce the hardness of the grommet arranged between the gear box and the vehicle body to make it difficult to transmit vibration to the vehicle body.

[0004]

However, when the hardness of the grommet is lowered, there is a problem that the steering stability (the response of the vehicle when the steering wheel is operated, etc.) is deteriorated.

In the past, since the entire grommet was molded from the same rubber (that is, the hardness was single), the entire grommet must be formed from rubber having a high hardness when the steering stability is emphasized. In other words, if importance is attached to vibration absorption, it is necessary to form the entire grommet with rubber having low hardness, and it is not possible to achieve both steering stability and vibration absorption.

Particularly, conventionally, there has been no consideration regarding vibration absorption and steering stability in the axial direction of the steering gear box.

In view of the above facts, it is an object of the present invention to provide a steering gear box support device which can achieve both steering stability and vibration absorption. In particular, the present invention aims to achieve both steering stability and vibration absorption in the axial direction (rack bar movement direction) of the steering gear box.

[0008]

According to a first aspect of the present invention, there is provided a steering gear box support for holding a grommet fitted in a steering gear box by a mounting portion of a vehicle body and a fastening bracket connected to the mounting portion. In the device, the grommet has a plurality of elastic members having different spring constants in the axial direction of the steering gear box.

According to a second aspect of the present invention, in the steering gear box support device, the grommet fitted into the steering gear box is held by a mounting portion of the vehicle body and a tightening bracket connected to the mounting portion. The grommet has a plurality of elastic members having different spring constants, and when the axial force generated in the steering gear box is less than a predetermined value, the grommet is tightened with the steering gear box via the elastic member on the high spring constant side. It is characterized in that it has a connecting means for connecting the bracket and the steering gear box and the tightening bracket via an elastic member on the low spring constant side when the axial force is a predetermined value or more.

[0010]

According to the steering gear box support device of the first aspect, the grommet acts on the steering gear box because it has a plurality of elastic members having different spring constants in the axial direction of the steering gear box. When the axial force (axial load) is small (for example, when the vehicle travels straight at a high vehicle speed), the elasticity of the elastic member on the high spring constant side can support the steering gear box to enhance steering stability. When the axial force acting on the box is large (for example, when the vehicle speed is low during steering), the elasticity of the elastic member on the low spring constant side supports the steering gear box and the steering gear box vibrates to the vehicle body (such as goo noise). Transmission can be interrupted.

Further, according to the steering gear box support device of the second aspect, when the axial force acting on the steering gear box is less than a predetermined value (for example, when the vehicle speed is straight ahead, etc.), the connecting means is high. Since the elastic member on the spring constant side and the steering gear box are connected, steering stability can be improved. On the other hand, when the axial force exceeds a predetermined value (for example, during steering at a low vehicle speed), the connection between the elastic member on the high spring constant side and the steering gear box is released, and the elastic member on the low spring constant side and the steering gear box are released. Since the steering gear box is supported by the elasticity of the elastic member on the low spring constant side, the transmission of vibrations (such as goo noise) from the steering gear box to the vehicle body can be blocked.

[0012]

【Example】

[First Embodiment] A first embodiment of the present invention will be described with reference to FIGS.

As shown in FIGS. 1 and 2, a single elastic material (for example, rubber, urethane, synthetic resin, etc.) is provided at a predetermined position on the outer peripheral surface of the gear housing (or rack tube) 10 of the gear box of the steering device. ) The tubular grommet 12 formed by (4) is fitted.

On the outer peripheral surface of the gear housing 10, flange portions 14L and 14R are integrally formed on both sides of the grommet 12.

As shown in FIG. 2, the gear housing 10
The lower portion 10A and both side portions 10B have a planar shape, and the upper portion 10C has a semi-circular shape.

As shown in FIGS. 1 and 2, the grommet 1
The reference numeral 2 is held by a mounting portion 16 of the vehicle body located below the gear housing 10 and a tightening bracket 18 mounted on the mounting portion 16. In addition, this grommet 1
A notch 12 </ b> A is formed in the shaft 2 along the axial direction in order to facilitate attachment to the gear housing 10.

The tightening bracket 18 is the gear housing 1
U-shaped part 1 facing both side parts 10B and upper part 10C of 0
8A and the flat surface portion 1 provided on both sides of the U-shaped portion 18A
8B, and the flat surface portion 18B is fixed to the mounting portion 16 with the bolt 20 and the nut 22.

The U-shaped portion 18 is provided outside the U-shaped portion 18A.
An elastic body holding cover 24 is arranged along the outer peripheral surface of A. The elastic body holding cover 24 is formed of a thick metal plate or the like.

On the inner peripheral surface of the elastic body holding cover 24, a shallow groove 26 extending along the inner peripheral direction on both sides in the width direction (left and right direction in FIG. 1) and a wide deep groove 28 formed inside thereof are formed. Has been done.

The elastic body holding cover 24 is attached by bolts 30 to a projecting portion 18C formed in the outer peripheral surface of the U-shaped portion 18A of the tightening bracket 18 and extending in the outer peripheral direction at the center portion in the width direction. .

The deep groove 28 and U of the elastic body holding cover 24
A substantially U-shaped low-hardness elastic member (for example, rubber, urethane, synthetic resin, or the like) 36 is disposed on the side of the protruding portion 18C in the space formed between the shallow groove 26 and the character-shaped portion 18A.
A slide plate 34 formed of a rigid member such as metal or hard resin is arranged on the side. It should be noted that this slide plate 34 is provided in the deep groove 28 with the elastic body holding cover 2
4 and the tightening bracket 18 are slidable in the axial direction.

On the other hand, in the shallow groove 26 of the elastic body holding cover 24, a substantially U-shaped high hardness elastic member (for example, rubber, urethane, synthetic resin, etc.) 32 is arranged.

In the neutral state where the steering wheel is not operated (the state shown in FIG. 1), the high hardness elastic member 32 is separated from the flange portions 14L and 14R by a predetermined dimension, and is substantially compressed in the axial direction. It is not in a state (so-called free state).

On the other hand, the low hardness elastic member 36 arranged in the deep groove 28 is attached in a state of being compressed by a predetermined amount in the axial direction, and the slide plate 34 is attached to the shallow groove 26 and the deep groove 28.
And a predetermined force (hereinafter referred to as a set load of the low-hardness elastic member 36. In this embodiment, about 100 kgf).

The grommet 12 is formed of an elastic body having low rigidity in order to absorb the movement and vibration of the gear housing 10 in the direction perpendicular to the axis.

The grommet 12 and the tightening bracket 1
8, the elastic body holding cover 24, the high hardness elastic member 32, the slide plate 34, and the low hardness elastic member 36 constitute the steering gear box support device of the present invention.

Next, the operation of this embodiment will be described. When the steering wheel is steered, an axial load (axial force) acts on the gear housing (and rack tube) 10 of the gear box.

As shown in FIG. 3, the gear housing 10
However, if the axial load F moves to the right side of the drawing, the slide plate 34 on the left side of FIG. 3 does not separate from the step portion until the axial load F reaches the set load of the low hardness elastic member 36. Only the high hardness elastic member 32 on the left side is compressed. That is, as shown in FIG. 5, until the axial load F of the gear housing 10 reaches the set load of the low hardness elastic member 36, the movement (displacement) of the gear housing 10 becomes a high spring constant of the high hardness elastic member 32. Therefore, the axial displacement of the gear housing 10 is suppressed to be small.

On the other hand, the axial load F of the gear housing 10
4 exceeds the set load of the low hardness elastic member 36, the slide plate 34 separates from the step portion and slides to the right side in FIG. 4 as shown in FIG. 4, and the low hardness elastic member 36 is compressed. Therefore, when the set load is exceeded, the movement (displacement) of the gear housing 10 is governed by the low spring constant of the low-hardness elastic member 36 (strictly speaking, the high-hardness elastic member 32 and the low-hardness elastic member 36). Is controlled by a spring constant connected in series), as shown in FIG.
The zero movement (displacement) is governed by the low spring constant of the low hardness elastic member 36, and the axial displacement of the gear housing 10 increases.

That is, during normal running, the gear housing 10
Since the axial rigidity of is high, steering stability is maintained. on the other hand,
The axial rigidity of the gear housing 10 is lowered and the axial vibration is reduced only when a large axial force is applied during stationary steering (particularly, in a vehicle equipped with a power steering device, during steering such that a pump goo noise is generated). Can be absorbed. Therefore, it is possible to achieve both steering stability and prevention of abnormal noise. The vibration of the gear housing 10 in the direction perpendicular to the axis (radial direction) is caused by the grommet 1 having low rigidity.
2 well absorbed.

Although not shown, the high-hardness elastic member 32 and the low-hardness elastic member 36 bulge in the direction perpendicular to the compression direction when they are compressed.
It is preferable to provide a predetermined gap in a portion facing the elastic body holding cover 8 and the elastic body holding cover 24.

The high hardness elastic member 32 and the low hardness elastic member 36 may be foamed rubber, sponge or the like,
It can be replaced with a spring made of metal or the like.

Although the set load of the low hardness elastic member 36 is set to about 100 kgf in this embodiment, it is a value that is changed depending on the type of automobile and the set load is not limited to this. [Second Embodiment] A second embodiment of the present invention will be described with reference to FIGS. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 6, the tightening bracket 50 of the present embodiment differs from the tightening bracket 18 of the first embodiment in that the shallow groove 26 and the deep groove 28 are not formed, and the inner peripheral surface of the tightening bracket 50 is not formed. The high hardness elastic member 52 is adhered.

A sliding member 54 as a connecting means is embedded in the inner peripheral surface of the high hardness elastic member 52. The sliding member 54 has a curved cross-sectional shape, and when the steering is in the neutral state (state of FIG. 6), the center portion of the bending is a semi-circular projection 56 formed on the outer peripheral surface of the gear housing 10. It corresponds.

The high hardness elastic member 52 is compressed by a predetermined amount in the direction perpendicular to the axis, and the sliding member 54 is pressed against the outer peripheral surface of the gear housing 10 with a predetermined force. Therefore, when the axial load of the gear housing 10 is less than the predetermined value, the sliding member 54 is not held by the frictional force and does not slide on the outer peripheral surface of the gear housing 10 (in a connected state), and the sliding member 54 has a predetermined value or more. At the time of, it will slide (non-connected state).

On the other hand, low hardness elastic members 58 are adhered to the inner surfaces of the flange portions 14L and 14R, respectively, and these low hardness elastic members 58 are in contact with the side surfaces of the high hardness elastic member 52.

Next, the operation of this embodiment will be described. In this embodiment, the gear housing 10 is operated by steering.
When an axial load is applied to the gear housing 10, when the axial load is small, the axial load is applied from the gear housing 10 to the high hardness elastic member 52 by the sliding resistance between the sliding member 54 and the gear housing 10. Although transmitted to the tightening bracket 50 (vehicle body), when the axial load is large, the sliding member 54 slides on the outer periphery of the gear housing 10, so that the axial load is transmitted by the low hardness elastic member 56. Become.

The relationship between the axial load and the transmission force from the gear housing 10 to the vehicle body has the characteristics shown in the graph of FIG. 7, which is large during normal traveling (for example, when the vehicle is traveling straight at high vehicle speed). When no axial load (axial force) is generated,
The rigidity of the gear housing 10 is high in the axial direction by the high hardness elastic member 52, so that the steering stability is maintained.

On the other hand, a large axial load (axial force) is generated during stationary steering (for example, during steering at a low vehicle speed, especially in steering where a goo noise is generated by a pump in a vehicle equipped with a power steering device). When it occurs, the rigidity of the gear housing 10 in the axial direction is lowered by the low-hardness elastic member 58, so that it is possible to absorb axial vibrations and abnormal noises. Therefore, it is possible to achieve both steering stability and prevention of abnormal noise.

When the steering is returned to the neutral state, the curved center portion of the sliding member 54 is guided by the projection 56 of the gear housing 10 to automatically perform centering.

Further, the high hardness elastic member 52 and the low hardness elastic member 58 may be foamed rubber, sponge or the like,
It can be replaced with a spring made of metal or the like. [Third Embodiment] A third embodiment of the present invention will be described with reference to FIG. The present embodiment is a modification of the second embodiment, and the same components as those in the second embodiment are designated by the same reference numerals,
The description is omitted.

In this embodiment, a compression coil sprig 62 and a ball 64 are put in a hole 60 formed in the gear housing 10, and the ball 64 is pressed against the sliding member 54 with a predetermined force.

In this embodiment, when the steering is returned to the neutral state, the curved center portion of the sliding member 54 is guided by the biased ball 64 to automatically perform centering.

The other functions and effects are similar to those of the second embodiment. [Fourth Embodiment] A fourth embodiment of the present invention will be described with reference to FIG. The present embodiment is a modification of the second embodiment, and the same components as those in the first and second embodiments are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 9, an inner flange 72 is formed on both sides in the axial direction of the tightening bracket 70 of this embodiment, and a semicircular cross section is formed at the central portion of the inner peripheral surface in the axial direction. Projections 74 are formed.

On the other hand, a protrusion 76 having a rectangular cross section is formed on the outer peripheral surface of the gear housing 10. A high hardness elastic member 78 is adhered to the outer peripheral surface of the protrusion 76.

A sliding member 80 as a connecting means is adhered to the outer peripheral surface of the high hardness elastic member 78. A part of the center of the sliding member 80 is curved, and when the steering is in the neutral state (state of FIG. 9), the curved center portion corresponds to the protrusion 74 of the tightening bracket 70.

The high hardness elastic member 78 is compressed by a predetermined amount in the direction perpendicular to the axis, and the sliding member 80 is pressed against the inner peripheral surface of the tightening bracket 70 by a predetermined force. Therefore, when the axial load of the gear housing 10 is less than the predetermined value, the sliding member 80 is not held by the frictional force and does not slide on the inner peripheral surface of the tightening bracket 70 (in the connected state), and the predetermined direction is maintained. If the value is greater than the value, it will slide (unconnected state).

Further, low hardness elastic members 82 are bonded to both side surfaces in the axial direction of the projection 76, and these low hardness elastic members 82 are in contact with the inner side surface of the inner flange 72.

Next, the operation of this embodiment will be described. In this embodiment, the gear housing 10 is operated by steering.
When an axial load is applied to the gear housing 10 and the axial load is small, the axial load is transmitted from the gear housing 10 to the high hardness elastic member 78 by the sliding resistance between the sliding member 80 and the tightening bracket 70. When the axial load is large, the sliding member 80 slides on the inner circumference of the clamping bracket 70, so that the axial load is transmitted by the low hardness elastic member 82. Will be.

That is, similarly to the second embodiment, this embodiment shows the relationship between the axial load and the transmission force from the gear housing 10 to the vehicle body as shown in the graph of FIG.
It is possible to achieve both steering stability and prevention of abnormal noise.

When the steering wheel is returned to the neutral state, the curved center portion of the sliding member 80 is guided by the projection 74 of the tightening bracket 70 to automatically perform centering.

Further, the high hardness elastic member 78 and the low hardness elastic member 82 may be foamed rubber, sponge or the like,
It can be replaced with a spring made of metal or the like. Further, the projection 74 may be replaced with the compression coil sprig 62 and the ball 64 shown in the third embodiment.

In the first embodiment, the gear housing 1
Although 0 is received in the axial direction by two kinds of elastic members, the low hardness elastic member 36 and the high hardness elastic member 32, the present invention is not limited to this, and the number of steps, slide plates and elastic members can be further increased. It is also possible to change the characteristics in two or more steps.

In the second to fourth embodiments corresponding to claim 2, the elastic member on the high spring constant side is provided with the connecting means. However, the present invention is not limited to this, and on the contrary, the elastic member on the low spring constant side is provided. It is also possible to provide a connecting means to the above, and by this, the same action and effect can be obtained.

[0057]

As described above, in the steering gear box supporting apparatus according to the first aspect, the grommet has a plurality of elastic members having different spring constants in the axial direction of the steering gear box, When the axial force acting on the gear box is small (for example, when the vehicle is traveling straight at a high vehicle speed), the elasticity of the elastic member on the high spring constant side supports the steering gear box, and the axial force acting on the steering gear box is large ( For example, when steering at a low vehicle speed), since the steering gear box is supported by the elasticity of the elastic member on the low spring constant side, both steering stability and vibration absorption can be achieved, and especially vibration absorption in the axial direction can be improved. It has an excellent effect that

Further, in the steering gear box support device according to the second aspect of the invention, the connecting means has a high spring constant when the axial force acting on the steering gear box is less than a predetermined value (for example, when the vehicle speed is straight ahead). Since the elastic member on the side and the steering gear box are connected, and when the axial force is a predetermined value or more (for example, at the time of steering at a low vehicle speed), the elastic member on the low spring constant side and the steering gear box are connected. It has an excellent effect that both the steering stability and the vibration absorbing property can be achieved at the same time, and particularly the vibration absorbing property in the axial direction can be enhanced.

[Brief description of drawings]

FIG. 1 is a sectional view taken along the axis of a steering gear box support device according to a first embodiment.

FIG. 2 is a sectional view taken along line 2-2 of the steering gear box support device shown in FIG.

FIG. 3 is a sectional view taken along the axis of the steering gear box support device, showing a state when an axial load equal to or less than a set load is applied.

FIG. 4 is a sectional view taken along the axis of the steering gear box support device, showing a state when an axial load exceeding the set load is applied.

FIG. 5 is a graph showing the relationship between axial force and axial displacement.

FIG. 6 is a sectional view taken along the axis of the steering gear box support device according to the second embodiment.

FIG. 7 is a graph showing the relationship between axial load and transmission force.

FIG. 8 is a sectional view taken along the axis of a steering gear box support device according to a modification of the third embodiment.

FIG. 9 is a cross-sectional view taken along the axis of a steering gear box support device of a fourth embodiment.

[Explanation of symbols]

 10 Gear Housing (Steering Gear Box) 12 Grommet 16 Mounting Part 18 Tightening Bracket 24 Elastic Body Holding Cover 32 High Hardness Elastic Member 34 Slide Plate 36 Low Hardness Elastic Member 52 High Hardness Elastic Member 54 Sliding Member (Connecting Means) 58 Low Hardness elastic member

Claims (2)

[Claims] 1. A steering gear box supporting device for holding a grommet fitted into a steering gear box by a mounting portion of a vehicle body and a tightening bracket connected to the mounting portion, wherein the grommet is a shaft of the steering gear box. A steering gear box support device having a plurality of elastic members each having a spring constant different from each other in a direction. 2. A steering gear box support device for holding a grommet fitted in a steering gear box by a mounting portion of a vehicle body and a tightening bracket connected to the mounting portion, wherein the grommet has different spring constants. In addition to having a plurality of elastic members, when the axial force generated in the steering gear box is less than a predetermined value, the steering gear box and the tightening bracket are connected to each other via the elastic member on the high spring constant side, and the axial force is increased. Is greater than or equal to a predetermined value, the steering gear box support device has a connecting means for connecting the steering gear box and the tightening bracket via an elastic member on the low spring constant side.