JPH08303507A - Compression coil spring - Google Patents

Abstract

PURPOSE: To set a lateral warping ratio of a compression coil spring to be a specific value or less by setting an effective winding number within a specific range. CONSTITUTION: An effective winding number of a compression coil spring is set to be within a range of (n+0.5)±0.125 (n: integer). A lateral warping ratio of the compression coil spring can thus be set to be 0.022 or less. In the case of parallel compression in which contact of wire with each other is not generated, an approximate curve determined by least square based on result of finite element analysis using a specified spring specifications well coincides with an actually measurement value. When the effective winding number ne is an integer, a lateral warping ratio η=δ/W (δ: maximum lateral warping, W: warping quantity) becomes the maximum value, it becomes the minimum value when ne is an integer + 0.5, the minimum value is constant though the maximum value is decreased as ne is increased, and when ne is within a range of (n+0.5)±0.125 (n: integer), η becomes 0.022 or less, where lateral warping is so small that it is substantially no problem.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compression coil spring which is widely used as a suspension spring for passenger cars.

[0002]

2. Description of the Related Art A compression coil spring for a suspension spring of a passenger car has been improved in strength and processing technology in order to meet the ever-increasing needs for weight reduction. As a result, design stress has been reduced in the last 15 years. 1.4 times higher, the spring mass is about 40
% Reduced.

However, as the weight of the spring is reduced, the lateral deflection of the spring is increased, and there is a problem that interference with the body must be taken into consideration.

In a spring having a large coil aspect ratio (spring height / coil average diameter), a buckling phenomenon occurs when the amount of deflection of the spring exceeds a limit value even in the case of parallel compression, and a large deflection is generated in the lateral direction. The present invention relates to lateral deflection caused by the influence of load eccentricity from the initial stage of compression in the case of parallel compression of a spring having a small aspect ratio.

[0005]

The problem to be solved by the present invention is to set the lateral deflection ratio of the compression coil spring to 0.022.
It is to do the following.

[0006]

As a means for solving the above problems, the present invention has an effective number of turns of (n + 0.5) ±
The configuration is within the range of 0.125 (n: integer).

[0007]

The present invention has the above-described structure, and when the number of effective turns is n + 0.5, the lateral deflection becomes a minimum value, and the lateral deflection ratio within the range of 0.125 before and after that is 0.0.
It will be 22 or less.

[0008]

[Examples] When there is no line contact due to parallel compression, the results of finite element analysis using the spring specifications shown in Table 1 and FIG. 2 are represented by the circles in FIG. 1, and the minimum two The approximate curve obtained by the multiplication method is shown in the same figure, and the measured value is shown by the X mark in the figure.

[Table 1] In FIG. 1, when the number of effective turns n _e is an integer, the lateral deflection ratio η
= Δ / W (δ: maximum lateral deflection, W: amount of deflection) has a maximum value, which is a minimum value when the integer +0.5, and the maximum value decreases as n _e increases, but the minimum value remains constant. Therefore, it was found that n _e was 0.022 or less in the range of (n + 0.5) ± 0.125 (n: integer), and the lateral deflection was so small as not to be a practical problem.

[Brief description of drawings]

FIG. 1 is a graph showing changes in a lateral deflection ratio η corresponding to the number of effective turns n _e .

FIG. 2 is a cross-sectional view showing a lateral deflection of a compression coil spring.

[Explanation of symbols]

_ne : Effective number of turns W: Compression amount δ: Maximum lateral deflection η: Lateral deflection ratio

Claims (1)

[Claims] 1. The number of effective turns is (n + 0.5) ± 0.125.
A compression coil spring characterized by being within a range of (n: integer).