JP2003320940A - Rack and pinion type steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rack and pinion type steering device to minimize uncomfortable noise at a low cost. <P>SOLUTION: A cushioning member 30 in a rectangular form is intervened between a rack 11 and a joint housing 21. A central hole 31 for passing a thread axis 22 is formed in the center of the cushioning member 30, and a rising part 32 is formed around each of four corners of it. The rising part 32 is formed into a roughly curved form in cross section so as to generate a space 33 between the cushioning member 30 and the joint housing 21, and when sandwiched between an end part of the joint housing 21 and the end part for a housing 10, it absorbs a shock by being elastically deformed from the profile curvature form into the flat form. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rack and pinion type steering device, and more particularly, when a steering wheel is turned to its turning limit position, a warning sound is emitted to inform that the turning position is the turning limit position. The present invention relates to a rack and pinion type steering device that does not produce noise.

[0002]

In the rack and pinion type steering device, when the steering wheel is turned, the pinion rotates, and the rotational movement of the pinion is transmitted through the meshing of the pinion and the rack in the axial direction of the rack. Is converted to a linear motion, and the direction of the left and right wheels is switched via ball joints, tie rods, etc. connected to both ends of the rack in the axial direction. At the turning limit of the steering wheel, at one end of the rack, the rack retracts into its housing to the retract limit position. At this time, the end of the joint housing of the ball joint connected to the end of the rack hits the housing end of the rack and emits sound. Therefore, the driver knows that the steering wheel has been turned to the turning limit position.

The sound produced when the joint housing end of the ball joint hits the rack housing end is
Although necessary as a warning sound that the steering wheel has turned to its turning limit position, this warning sound is a sound emitted when metal parts collide with each other, and sometimes becomes a very unpleasant sound to the driver. Sometimes.

Therefore, for example, a rubber ring is interposed between the rack and the joint housing to prevent the end portion of the joint housing from directly contacting the housing end portion of the rack, while absorbing the impact. A rack and pinion type steering device has been proposed in which the unpleasant sound is attenuated as much as possible.

However, when a rubber ring is used, the reliability is poor in terms of strength, and it is necessary to use a material formed of a material that is tough to some extent, which causes a problem of high cost.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rack and pinion type steering device which does not increase the cost and attenuates unpleasant noise as much as possible.

[0007]

In a rack and pinion type steering device of the present invention which achieves the above object, a rack is movably inserted in a housing in an axial direction, and a joint housing of a ball joint is connected to an end portion of the rack. In the rack and pinion type steering device, a buffer member is interposed between the rack and the joint housing, and when the rack retracts into the housing, the buffer member and the end portion of the housing The present invention is characterized in that a ridge that is sandwiched between the joint housing and absorbs an impact is arranged.

When the steering wheel is turned to its turning limit position, the rack retracts into the housing,
The ridge is sandwiched between the end of the housing and the joint housing. Since the ridge is formed to absorb impact, the unpleasant sound generated at this time is attenuated as much as possible.

The raised portion is formed, for example, so that a gap is formed between the buffer member and the end portion of the joint housing. By forming the raised portion so as to have a cross-sectional shape of, for example, a beat shape, a corrugated shape, a conical shape, a bent shape, a deep drawing shape, or a trapezoidal drawing shape in cross section, it is possible to form a gap with the end of the joint housing. A gap can be created in.

While a screw hole is provided at the end of the rack, a screw shaft screwed into the screw hole is provided at the end of the joint housing, or a screw shaft is provided at the end of the rack.
When a screw hole into which the screw shaft is screwed is provided in the joint housing and the end portion of the joint housing is screwed to the end portion of the rack, the cushioning member can have a function of preventing loosening of the screw fastening. Further, it is possible to provide the raised portion on a washer interposed between the rack and the joint housing as a loosening prevention.

[0011]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings. 1 is a partially cutaway partial side view showing an embodiment of a rack and pinion type steering device of the present invention, FIG. 2 is a plan view of a specific example of a cushioning member, FIG. 3 is the same side view, and FIGS. FIG. 2 shows a modified example of the raised portion.
FIG. 3 is a partial cross-sectional view as seen from the direction A of FIG.

According to the steering apparatus of the present embodiment, the cylindrical rack 11 is arranged in the housing 10 so as to be movable in the axial direction (left and right direction in FIG. 1).
1 projects in and out from the end of the housing 10 in the axial direction. Rack teeth (not shown) are formed on the rack 11 at appropriate points on the surface of the intermediate portion in the axial direction, and pinions (not shown) mesh with the rack teeth. A screw hole 12 is formed at the end of the rack 11 in the axial direction, while a screw shaft 22 is formed at the end (center of the end face) of the joint housing 21 of the ball joint 20. Two
By screwing 2 into the screw hole 12, the ball joint 20 is screwed to the end of the rack 11.

A substantially rectangular plate-shaped cushioning member 30 is interposed between the end of the rack 11 and the end of the joint housing 21 on the side where the screw shaft 22 is formed. In the buffer member 30, a central hole 31 through which the screw shaft 22 is inserted is formed in the central portion thereof, and raised portions 32 are respectively formed near the four corners thereof.

The raised portion 32 is formed, for example, in a substantially curved cross section so that a gap 33 is formed between the cushioning member 30 and the joint housing 21. The raised portion 32 corresponds to the rack 11
Is retracted into the housing 10 to its retracted limit position, the end of the joint housing 21 and the housing 10
The impact is absorbed by being sandwiched between the end portion and the end portion and elastically deforming from a substantially curved state to a substantially flat state.

As shown in FIGS. 2 and 3, the cushioning member 30 is provided with claw pieces 34 on its left and right side portions and upper and lower end portions, respectively. The cushioning member 30 is interposed between the end of the rack 11 and the end of the joint housing 21, and the claw piece 3
4 is pressed against the side surface of the joint housing 21 so as to sandwich the joint housing 21 to prevent rotation, and the screw shaft 22 is screwed into the screw hole 12 and tightened. As a result, the cushioning member 30 is sandwiched between the rack 11 and the joint housing 21 in a fixed state.

The buffer member 30 is formed, for example, by drawing a metal plate having an appropriate thickness. At the time of this drawing, the central hole 31 is formed by punching. The raised portion 32 is drawn so as to have a substantially curved shape, and the claw piece 34 is bent at a substantially right angle to the joint housing 21 side.

The end of the rack 11 is connected to the left and right wheels via a ball joint 20 and tie rods (not shown). Although not shown, the outer peripheral portion between the housing 10 and the ball joint 20 is surrounded by a bellows-shaped boot.

Next, the operation of the steering system of the above embodiment will be described. A pinion (not shown) rotated by turning a steering wheel (not shown)
The rack 11 linearly moves in the housing 10 through the meshing of the rack 11 and the rack 11, and this linear motion is converted into a motion that switches the direction of the left and right wheels by the ball joint 20, the tie rod, and the like. When the steering wheel is turned to its turning limit position, at the end portion on the rack 11 side that retracts into the housing 10 by this turning operation,
The end of the rack 11 is moved to the retracted limit position of the housing 10
Retracting inward, the end of the joint housing 21 approaches the end of the housing 10, and finally the ridge 32 of the cushioning member 30 is between the end of the joint housing 21 and the end of the housing 10. Sandwiched. This prevents the end of the joint housing 21 from directly colliding with the end of the housing 10, while elastically deforming the raised portion 32 from a substantially curved state to a substantially flat state. Therefore, although a sound (warning sound) is generated when the raised portion 32 hits the end portion of the housing 10, an unpleasant sound generated by collision between metal parts is attenuated as much as possible.

In the above embodiment, the raised portion 3 having a substantially curved cross section.
Since the impact is absorbed by elastically deforming 2, the steering wheel is turned to a turning limit position with a large force, and the joint housing 21
Even if the end portion of the member strongly collides with the end portion of the housing 10 via the cushioning member 30, the shock generated at that time can be sufficiently absorbed.

Further, the cushioning member 30 is formed by drawing a metal plate, and since the raised portion 32 is formed at the same time as this drawing, the manufacturing cost is greatly increased as compared with the case of a rubber ring. It is possible to reduce.

Further, the cushioning member 30 is interposed between the rack 11 and the ball joint 20, and also functions as a loosening stopper for screw fastening (screw engagement between the screw hole 12 and the screw shaft 22) between them. Therefore, the lock washer can be omitted.

4 to 9 show modified examples of the raised portion 32. FIG. 4 shows a corrugated cross section, FIG. 5 shows a beaded cross section, and FIG.
FIG. 6 is a sectional bent shape (substantially corrugated having a larger amplitude than that shown in FIG. 4), FIG. 7 is a conical sectional shape, FIG. 8 is a trapezoidal sectional shape, and FIG. It shows the case of forming each of them.

The present invention is not limited to the one shown in the above embodiment, and various modifications can be made within the scope of the claims. The cross-sectional shape of the raised portion 32 is
The present invention is not limited to the one shown in the above-mentioned embodiment, and in short, it may be sandwiched between the housing 10 and the joint housing 21 to absorb the shock. Further, by forming the raised portion 32 on the existing washer used as a loosening prevention member between the rack and the ball joint, the cushioning member 30 can be obtained.

[0024]

As described above, according to the rack and pinion type steering device of the present invention, when the rack is retracted into the housing, the end of the housing is provided in the buffer member interposed between the rack and the joint housing. Since a raised portion that is sandwiched between the portion and the joint housing to absorb the impact is arranged, an unpleasant sound generated when the steering wheel is turned to its turning limit position can be attenuated as much as possible. In addition, the cushioning member can be easily manufactured by, for example, drawing a metal plate, and the manufacturing cost can be reduced as compared with the rubber ring.

[Brief description of drawings]

FIG. 1 is a partially cutaway partial side view showing an embodiment of a rack and pinion type steering device of the present invention.

FIG. 2 is a plan view of a specific example of a buffer member.

FIG. 3 is a side view of the cushioning member of FIG.

FIG. 4 is a partial cross-sectional view as seen from the direction A of FIG. 2, showing a modified example of the raised portion.

FIG. 5 is a partial cross-sectional view as seen from the direction A in FIG. 2, showing a modified example of the raised portion.

FIG. 6 is a partial cross-sectional view as seen from the direction A in FIG. 2, showing a modified example of the raised portion.

7 is a partial cross-sectional view as seen from the direction A in FIG. 2, showing a modified example of the raised portion.

FIG. 8 is a partial cross-sectional view as seen from the direction A in FIG. 2, showing a modified example of the raised portion.

9 is a partial cross-sectional view as seen from the direction A in FIG. 2, showing a modified example of the raised portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Housing 11 Rack 12 Screw hole 20 Ball joint 21 Joint housing 22 Screw shaft 30 Buffer member 31 Central hole 32 Raised part 33 Gap 34 Claw piece

Claims (4)

[Claims] 1. A rack-and-pinion steering apparatus comprising: a rack in which a rack is axially movable so that a joint housing of a ball joint is connected to an end of the rack; A cushioning member is interposed between the cushioning member and the cushioning member, and when the rack is retracted into the housing, a bump that is sandwiched between the end of the housing and the joint housing to absorb a shock is disposed. A rack and pinion type steering device characterized in that 2. The rack and pinion steering device according to claim 1, wherein the raised portion has a cross-sectional shape such that a gap is formed between the buffer member and the joint housing. The rack and pinion type steering device. 3. The rack and pinion steering apparatus according to claim 2, wherein the raised portion has a beat shape in cross section,
A rack and pinion steering device having a cross-sectional shape of any of a wave shape, a conical shape, a bent shape, a deep drawing shape, and a trapezoidal drawing shape. 4. The rack and pinion steering device according to claim 1, wherein an end portion of the joint housing is screwed to an end portion of the rack, and the buffer member loosens the screw fastening. A rack and pinion steering device having a stopping function.