JPH07186652A - Shaft member fixing structure of suspension member made of light alloy - Google Patents

Abstract

PURPOSE:To surely install a shaft member on a suspension member made of light alloy, free from slackening. CONSTITUTION:A suspension member 10 made of light alloy and a shaft member 20 which is made of steel and is constituted so that one end part is press-fitted into a press-fitting hole 16 drilled on the suspension member 10 are provided, and a collar part 22 which extends outside in the radial direction contiguously to a press-fitted part 21 which is press-fitted into the press-fitting hole 16 is formed on the shaft member 20, and at least on one outer peripheral surface of the press-fitting part 21 or the collar part 22, a knurled part which extends in parallel to the axis line of the shaft member 20 is cut. Further, on the surface of the suspension member 10, a counterbore into which the collar part 22 is press-fitted is formed in a recessed form, and a cylindrical projection part 17 for receiving the collar part 22 is installed in projection along the outer periphery of the counterbore, and the projection part 17 is deformed toward the inside in the radial direction, and surrounds the outer peripheral part of the collar part 22 which is closely attached on the bottom surface of the counterbore, and slip-off is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fixing a suspension member made of a light alloy used for a suspension system of an automobile to a shaft member used for connecting the suspension member to a vehicle body or other suspension members. Regarding

[0002]

2. Description of the Related Art Various types of suspensions (suspension) for suspending automobile tires are used. For example, in strut suspensions, L-type lower arms and A-type lower arms are double wishbone type suspensions. In the above, suspension members such as a pair of upper and lower A arms are used. And, it is necessary to provide these suspension members with a shaft portion for fitting a shock absorbing bush interposed between the vehicle body and other suspension members. In the suspension member formed by, the shaft portion made of steel can be easily welded to the suspension member, or in the suspension member formed by casting, the shaft portion can be easily formed by machining. Can be provided.

By the way, in recent years, the suspension member is made of an aluminum alloy to reduce the unsprung weight, thereby enhancing the steering stability and riding comfort of the vehicle. However, if the suspension member is made of aluminum alloy, not only can steel bolts not be easily welded, but the strength and rigidity of the aluminum alloy material itself are lower than that of steel material.
If an aluminum alloy suspension member manufactured by forging or casting is machined to integrally form the shaft portion, the diameter of the shaft portion becomes large, which is inconvenient. Thereby, in the conventional aluminum alloy suspension member, a steel bracket having a shaft portion is manufactured as a separate component, and this bracket is screwed to the aluminum alloy suspension member. In the method, there is a problem that the number of parts is increased, the number of manufacturing steps and the number of mounting steps are increased, and not only the cost is increased, but also the weight of the steel bracket is increased and the weight of the entire suspension system is not reduced.

Therefore, various methods of press-fitting and fixing a steel shaft member into a hole formed in a suspension member made of an aluminum alloy have been studied.

[0005]

However, a large tightening torque for tightening the bush is applied to the shaft member, and after the suspension member is actually assembled to the vehicle, tension or bending input from the tire is applied. Alternatively, an impact load such as twist is repeatedly input. As a result, there is a problem that the press-fitting of the shaft member becomes loose only by press-fitting and fixing the shaft member into the hole formed in the suspension member made of aluminum alloy. Therefore, it is conceivable to use an adhesive to prevent the press-fitted portion from loosening, but the adhesive is difficult to handle, and it is required to be mass-produced at low cost like a suspension member, and the guarantee of strength is required. The required parts have a problem in their reliability.
Therefore, there has been a long-standing demand for the development of a shaft member fixing structure capable of securely attaching the shaft member to an aluminum alloy suspension member without loosening.

The present invention has been made in view of the above problems, and provides a shaft member fixing structure capable of securely mounting the shaft member on an aluminum alloy suspension member without loosening. The purpose is to

[0007]

The above object is to provide a suspension member made of a light alloy according to the present invention, and a steel shaft member having one end press-fitted into a press-fitting hole formed in the suspension member. The shaft member is provided with a flange portion that is adjacent to the press-fitting portion press-fitted into the press-fitting hole and extends outward in the radial direction, and at least the outer peripheral surface of one of the press-fitting portion and the collar portion is provided. A knurl extending parallel to the axis of the shaft member is engraved, and a counterbore hole into which the collar part is press-fitted is provided on the surface of the suspension member, and the collar part is formed along the outer periphery of the counterbore hole. A cylindrical projecting portion for receiving is provided, and the projecting portion is deformed inward in the radial direction and is press-fitted into the counterbore hole so as to surround the outer peripheral portion of the collar portion that is closely attached to the bottom surface thereof. Of a light alloy suspension member characterized by It is achieved by fixing structure wood.

[0008]

The shaft member is press-fitted into the suspension member, and the knurled carved in the press-fitting portion or the flange portion of the shaft member engages with the suspension member. Therefore, even if a large torsion moment acts on the shaft member, It does not rotate relative to the suspension member. Further, since the flange portion is in close contact with the bottom surface of the countersunk hole formed in the suspension member to support the shaft member, even if a large bending moment acts on the shaft member, this bending moment is press-fitted between the shaft member and the suspension member. Since it does not act directly on the part, the press-fitting between the shaft member and the suspension member does not loosen. Further, since the shaft member is press-fitted into the suspension member and the outer periphery of the collar portion is surrounded by the protrusion of the suspension member which is deformed inward in the radial direction, even if an external force in the axial direction acts on the shaft member. The member is not displaced in the axial direction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a structure for fixing a shaft member in a light alloy suspension member of the present invention will be described in detail below with reference to the accompanying drawings. Here, FIG. 1 is a cross-sectional view showing a state in which an end portion of a shaft member is press-fitted into a suspension member, and FIG. 2 is a cross-sectional view showing a state in which a protruding portion of the suspension member shown in FIG. 1 is deformed radially inward. 3 is a plan view of the suspension member made of a light alloy, and FIG. 4 is a sectional view of another embodiment shown in a state where the protrusion of the suspension member is deformed inward in the radial direction.

First, a suspension member made of a light alloy will be described with reference to FIG. The light alloy suspension member shown as a plan view in FIG. 3 is an L-shaped lower arm of a strut suspension generally used for suspending front wheels of an automobile. In this embodiment, an aluminum alloy material is used. It is manufactured by forging. The lower arm 10 has an upper side in the figure as a rear side of the vehicle body and a right side in the figure as an outer side of the vehicle body. Further, the upper end portion in the drawing is a connection portion 11 with the vehicle body, and is connected to the lower surface of the floor of the vehicle body through a bush (not shown) externally fitted to the shaft member 20 attached to the end surface 12. There is. The lower left end in the drawing is a cross member connecting portion 13 formed in a cylindrical shape, and is connected to the cross member via a bush (not shown) fitted in the cylindrical portion. The axis of the cylindrical portion and the axis of the shaft member 20 are made to coincide with each other, and the L-shaped lower arm can be swung around the axis C. Further, the lower right end in the drawing is a strut connecting portion 14, which is connected to the steering knuckle through a ball joint (not shown).
In addition, the central portion of the lower end in the drawing is a stabilizer link mounting portion 15 to which a stabilizer link (not shown) that damps rolling of the vehicle body is also mounted.

Next, one embodiment of the fixing structure of the shaft member in the aluminum alloy suspension member according to the present invention will be described with reference to FIG. First, the shaft member 20 will be described. The shaft member 20 has a substantially rod shape, and one end of the shaft member 20 is a cylindrical press-fitting portion 21 that is press-fitted into the lower arm 10, and the outer peripheral surface thereof has a knurl 21a.
Are engraved so as to extend in the axial direction of the shaft member 20. A disk-shaped brim portion 22 is integrally formed adjacent to the press-fitting portion 21 so as to extend outward in the radial direction perpendicular to the axis of the shaft member 20.
Further, a pair of bush fitting portions 23, 24 to which a cylindrical metal fitting (not shown) is fitted is provided on the side of the collar portion 22 opposite to the press-fitting portion 21. further,
A bush fixing screw portion 25 for fastening the bush is provided at the other end of the shaft member 20.

As shown in FIG. 1, the lower arm 10
A press-fitting hole 16 is formed coaxially with the axis C on the end face 12 of the connection portion 11 with the vehicle body, and a cylindrical protrusion 17 coaxial with the axis C is projected on the surface of the end face 12. It is set up. Then, the projecting portion 17 is provided with a counterbore hole 18 coaxially with the axis C, and the press-fitting portion 2 of the shaft member 20 is provided.
When 1 is press-fitted into the press-fitting hole 16, the collar portion 22 is press-fitted into the countersunk hole 18. The outer peripheral surface 17a of the projecting portion 17 is tapered so that the outer diameter becomes smaller toward the tip end side.

Next, a procedure for fixing the shaft member 20 to the lower arm 10 will be described with reference to FIGS. 1 and 2. In order to fix the shaft member 20 to the lower arm 10, first, as shown in FIG. 1, the press-fitting portion 21 of the shaft member 20 is press-fitted into the press-fitting hole 16 of the lower arm 10, and the collar portion 22 is attached to the bottom surface 18a of the counterbore hole 18. Make sure they are in close contact.

Next, using the fastening tool 30 shown in FIG.
A caulking operation is performed to deform the protrusion 17 radially inward. The fastening tool 30 has a cylindrical shape, and the through hole 31 has an inner diameter through which the shaft member 20 can be inserted, and one end of the through hole 31 is provided with a tapered surface 32 that expands outward. Has been. To perform the above-mentioned caulking operation, first, the lower arm 10 is firmly fixed, and the taper surface 32 of the fastening tool 30 is externally fitted to the outer peripheral surface 17a of the projecting portion 17. Then, the end of the fastening tool 30 on the opposite side of the lower arm 10 is pressed by a press machine (not shown), and the fastening tool 30
Is urged toward the lower arm 10. This allows
As shown in FIG. 2, the projecting portion 17 is deformed inward in the radial direction and surrounds the outer peripheral portion of the collar portion 22 of the shaft member 20.

Thus, according to the structure for fixing the shaft member in the suspension member made of aluminum alloy of this embodiment, the press-fitting portion 21 of the shaft member 20 is press-fitted into the press-fitting hole 16 of the lower arm 10 and the outer peripheral surface of the press-fitting portion 21. 21a provided on the
Engages with the inner peripheral surface of the press-fitting hole 16, so that even if a large torsional moment acts on the shaft member 20, the shaft member 20 does not rotate relative to the lower arm 10. Further, since the collar portion 22 of the shaft member 20 is press-fitted into the countersunk hole 18 and closely adheres to the bottom surface 18a of the countersunk hole 18 to support the shaft member 20, even if a large bending moment acts on the shaft member 20, this Since the bending moment does not directly act on the press-fitting portions of the shaft member 20 and the lower arm 10, the shaft member 2
The press fit between 0 and the lower arm 10 does not loosen. Further, since the outer peripheral portion of the collar portion 22 is surrounded by the projecting portion 17 which is deformed inward in the radial direction and is prevented from coming off, the axial displacement of the shaft member 20 with respect to the lower arm 10 is more reliably prevented.

In this embodiment, a knurl is formed on the outer peripheral surface of the press-fitting portion 21 of the shaft member 20,
It is not necessary to be caught by this, and even if the knurls 42a are engraved on the outer peripheral surface of the collar portion 42 as in the shaft member 40 shown in FIG. 4, the relative rotation of the shaft member 40 with respect to the lower arm 10 is prevented. Sufficient resistance torque can be obtained. Further, in this embodiment, the lower arm is manufactured from an aluminum alloy, but it is obvious to those skilled in the art that a light alloy such as magnesium or titanium may be used.

[0017]

Since the present invention is configured as described above,
The following excellent effects were obtained. That is, according to the method of fixing the shaft member in the light alloy suspension member of the present invention, the light alloy suspension member is provided with a steel shaft used for connecting the suspension member to the vehicle body or another suspension member. Even if an impact force input from the tire is applied, the member can be reliably fixed without loosening the press-fitted portion. As a result, it is not necessary to screw a bracket made of steel having a shaft portion manufactured as a separate component unlike the conventional case, so that the weight of the entire suspension device can be greatly reduced, and
The manufacturing cost can be reduced by omitting the man-hours for manufacturing the bracket and attaching the bracket to the suspension member. Also,
According to the present invention, since a steel shaft member having high strength and rigidity is fixed to a suspension member made of a light alloy, compared with a case where a shaft portion is formed by machining a suspension member made of a light alloy. The diameter of the shaft portion can be reduced. As a result, the bush attached to the shaft member can be downsized, so that not only can the vehicle body side attachment portion to which the bush is attached be downsized to reduce the weight of the vehicle body, but also the space around the suspension device can be expanded. The degree of freedom in design can be improved. Further, according to the method of fixing the shaft member in the suspension member made of light alloy of the present invention, the shaft member can be mechanically fixed to the suspension member. Compared to,
The assembly work can be performed easily and quickly, and the reliability can be easily improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which an end portion of a shaft member is press-fitted into a suspension member.

FIG. 2 is a cross-sectional view showing a state in which a protruding portion of a suspension member is deformed radially inward.

FIG. 3 is a plan view of a suspension member made of aluminum alloy.

FIG. 4 is a cross-sectional view of another embodiment showing a state where the protrusion of the suspension member is deformed inward in the radial direction.

[Explanation of symbols]

 10 Light Alloy Suspension Member 11 Vehicle Body Connection Part 12 End Face 13 Cross Member Connection Part 14 Strut Connection Part 15 Stabilizer Link Attachment Part 16 Press-Fit Hole 17 Projection 17a Outer Surface of Projection 18 Counterbore 18a Counterbore Bottom 20 Shaft Member 21 Press-fitting part 22 Collar part 23 Bush fitting part 24 Bush fitting part 25 Bush fixing screw part 30 Fastening tool 40 Shaft member of another embodiment 41 Press-fitting part 42 Collar part 42a Knurled

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoichi Taniguchi 5-3-8, Shiba, Minato-ku, Tokyo Within Mitsubishi Motors Corporation (72) Kenji Kato 5-33-8, Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Masahiro Okazaki 5-3-8, Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation

Claims (1)

[Claims] 1. A suspension member made of a light alloy, and a steel shaft member having one end press-fitted into a press-fitting hole formed in the suspension member, the shaft member being provided in the press-fitting hole. A collar portion extending radially outward is provided adjacent to the press-fitting portion to be press-fitted, and at least one outer peripheral surface of the press-fitting portion or the collar portion is engraved with a knurl extending parallel to the axis of the shaft member. And a counterbore hole into which the brim portion is press-fitted is provided on the surface of the suspension member, and a cylindrical protrusion for receiving the brim portion is provided so as to project along the outer periphery of the counterbore hole, and A shaft member in a suspension member made of light alloy, characterized in that the protrusion part is deformed inward in the radial direction and is press-fitted into the counterbore hole to surround the outer peripheral part of the collar part that is closely attached to the bottom surface thereof. Fixed structure.