JPH04224411A - Structure of suspension arm for car - Google Patents

Abstract

PURPOSE:To protect threaded parts of a turn buckle by preventing stress concentration in this part of turn buckle, and causing other part which is the weakest to go into failure (plastic deformation) first. CONSTITUTION:In the suspension arm structure as per invention including a turn buckle 2 as a length adjusting mechanism, a plastic deforming part 15 having a lower strength than thread parts 2A, 2B is provided in a position elsewhere than the treaded parts. Thereby the threaded parts are protected.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension arm structure for a vehicle, and more particularly to a suspension arm structure for a vehicle that protects a threaded portion of a turnbuckle.

0002

BACKGROUND OF THE INVENTION Conventionally, in the rear wheel suspension of a front-wheel drive vehicle, a suspension arm partially provided with a turnbuckle has often been used to adjust wheel alignment.

FIG. 4 is a rear view of a conventional example (rear wheel suspension of a front-wheel drive vehicle) (Fig. 5 of U.S. Pat. No. 64-17803).
.

In FIG. 4, 1 is a suspension arm, 2 is a turnbuckle forming a part of the suspension arm 1, 2A and 2B are turnbuckle screw parts, and 3 and 4 are brackets on the vehicle body (cross member) side and wheel side, respectively. It is. Further, 6 is a wheel, and 7 is an axle.

The axle 7 swings in the direction of the arrow depending on the unevenness of the road. FIG. 3 is an enlarged rear view of a turnbuckle used in a conventional suspension arm.

However, as shown in FIGS. 3 and 4, as a result of a minor accident such as running over a curb or falling into a hole on the road, in the conventional example, the weakest part was in the turnbuckle screw parts 2A and 2B, so first, the turnbuckle screw part 2A or 2B was The threads of the screws could easily undergo plastic deformation due to stress concentration, and there was a risk of fatigue failure relatively early due to subsequent repeated stress loading.

[0007] If the turnbuckle screw portion is damaged first, there is a problem that alignment adjustment becomes impossible.

[0008] Therefore, the inventors of the present invention have conducted extensive research into a means to protect the turnbuckle threaded portion as much as possible by moving the weakest point to a location other than the threaded portion of the turnbuckle, and have arrived at the present invention.

[0009]

[Object of the invention] The purpose of the present invention is to prevent stress concentration from occurring in the turnbuckle threaded portion, and to protect the turnbuckle threaded portion by first damaging (plastically deforming) the other weakest portion. It is.

0010

According to the present invention, there is provided a suspension arm structure for swingably supporting a wheel support member supporting a wheel with respect to a vehicle body, the suspension arm having a turnbuckle as a length adjustment mechanism. There is provided a suspension arm structure for a vehicle, characterized in that a plastically deformed portion having lower strength than the threaded portion is provided in a portion other than the threaded portion in order to protect the threaded portion.

The present invention will be explained in detail below using examples.

0012

Embodiment FIG. 1 is an enlarged rear view of Embodiment 1 of the present invention. In FIG. 1, there are bracket extensions 9, 9 made of mild steel plate on both sides of the turnbuckle 2, and fixing nuts 10, 10 are screwed into the threaded parts 2A, 2B. Screw part 2A that is screwed upside down
, 2B are screwed into or out of the fixing nuts 10, 10 to adjust the distance between the brackets 3, 4. Nuts 11, 11 are double nuts for preventing loosening.

In the first embodiment, one bracket extension 9
A score 15 is bored in the suspension arm, and when tensile or compressive stress is applied in the axial direction of the suspension arm, buckling (plastic deformation) occurs first at the score 15.

Next, FIG. 2 is an enlarged rear view of Embodiment 2 of the present invention.

In the case of this embodiment, the turnbuckle shaft is bent into a U-shape, and the bent parts 11, 11, 12, and 12 are the weakest parts of the entire turnbuckle, and the threaded part 2
It undergoes plastic deformation before A and 2B. In other words, the bent part 1
Nos. 1 and 12 have lower strength (yield point or yield strength if the cross-sectional area is the same).

[0016]

[Effects of the Invention] By carrying out the present invention, all of the above objects can be achieved.

In other words, stress concentration is prevented from occurring in the turnbuckle thread, and the other weakest part is damaged first.
(plastic deformation) to protect the turnbuckle thread. As a result, the initial damage can be made into a ductile fracture region rather than a sudden brittle fracture, and since a sudden fracture does not occur, the length of the suspension arm can be easily restored with a healthy turnbuckle thread even after damage has occurred. It can be adjusted. Furthermore, the turnbuckle screw portion is less likely to be damaged than in the past, making it safer.

[Brief explanation of the drawing]

FIG. 1 is an enlarged rear view of Embodiment 1 of the present invention.

FIG. 2 is an enlarged rear view of Embodiment 2 of the present invention.

FIG. 3 is an enlarged rear view of a conventional suspension arm structure.

FIG. 4 is a rear view showing a conventional suspension arm structure.

[Explanation of symbols]

1 Suspension arm 2 Turnbuckle 2A, 2B Turnbuckle screw part 3,4 Bracket 9 Bracket extension part 10 Fixed nut 11 Double nut 11, 12 Bent part

Claims (1)

[Claims] Claim 1: A suspension arm structure for swingably supporting a wheel support member supporting a wheel with respect to a vehicle body, wherein the suspension arm is provided with a turnbuckle as a length adjustment mechanism, in which a threaded portion is provided. A suspension arm structure for a vehicle, characterized in that a plastically deformed part having lower strength than the threaded part is provided in a part other than the threaded part for protection.