JP2001208116A - Compression coil spring - Google Patents

Abstract

(57) [Problem] To provide a compression coil spring configured so that a reaction axis can coincide with a center line of a bearing surface even when a compression load is applied. SOLUTION: A compression coil spring 2 is interposed between an upper seat 3 and a lower seat 4, and an axis perpendicular to a direction of a lateral force generated when a parallel compression load is applied to the compression coil spring. , At least one of the upper seat and the lower seat is inclined, and the reaction force axis RA generated in the compression coil spring connects the center of the upper seat surface US of the compression coil spring to the center of the lower seat surface LS. It is maintained at an inclination angle (for example, α) when it becomes parallel to the seat surface center line CL. In this state, in the direction in which the body portion 2c of the compression coil spring bulges in the direction opposite to the eccentric direction of the reaction force axis from the seat surface center line, the body portion is moved until the reaction force axis substantially matches the seat surface center line. Form a curve.

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, and more particularly to a compression coil spring which does not generate any lateral force or load eccentricity when a compressive load is applied.

[0002]

2. Description of the Related Art Conventionally, various compression coil springs have been known, and various measures have been taken to prevent a lateral force from being generated when a compressive load is applied. For example, a paper entitled "Technique to reduce lateral force of suspension coil spring in suspension design" (Spring Technology Research Society, 1995)
(August 28, 2008), it is an issue to minimize the lateral force of the compression coil spring, and it has been proposed to restrict the number of turns and tilt the seat of the compression coil spring used for the McPherson strut type suspension. I have.

[0003] The above-mentioned document states that even in the case of parallel compression in which the spring is compressed by displacing the spring seat only in the coil axis direction,
The load acting on the spring seat is eccentric, and a load component perpendicular to the coil axis (hereinafter referred to as lateral force) also occurs. "
For example, it is described that when the seat is inclined in a direction opposite to the direction of the lateral force acting on the lower spring seat during the parallel compression, the lateral force is minimized.

Japanese Patent Application Laid-Open No. 9-2039 discloses that a coil spring is provided so that the load axis of the coil spring substantially coincides with the axis of the damper rod in order to reduce the friction generated in the damper of the suspension device. It is stated that the geometric axis is inclined symmetrically about the center of the coil spring in the vertical direction with respect to the axis of the damper rod so that the load axis of the coil spring coincides with the axis of the damper rod. An embodiment applied to a suspension is disclosed.

[0005]

However, in the suspension device described in the above publication, a coil spring,
It is necessary to adjust the relationship with the mounting target damper rod, and as specific means, for example, the layout of both,
Significant changes are required to the previous configuration, such as the shape of the coil seat. That is, basically, it is not intended to reduce the friction generated in the damper only by improving the coil spring, and therefore, the entire suspension device is changed.

[0006] On the other hand, the above-mentioned document states that "since the spring offset is not performed in the multi-link suspension or the double wishbone suspension, the lateral force cannot be reduced by the above-described method". Attempts to change the corner have been made, but have not yet found a solution.

In the case of a compression coil spring which needs to be set so as not to generate a lateral force on the shaft to be supported, such as a compression coil spring provided for the above-mentioned double wishbone type suspension, the conventional lateral force reduction method employs a lateral coil. Even if the force is reduced, the load eccentricity may increase, and it is necessary to take a countermeasure. However, basically, it is difficult to solve the problem by using only the compression coil spring.

Accordingly, an object of the present invention is to provide a compression coil spring configured such that the reaction force axis can coincide with the center line of the bearing surface even when a compression load is applied.

[0009]

In order to solve the above-mentioned problems, a compression coil spring according to the present invention has a compression coil spring interposed between an upper seat and a lower seat. ,
Tilting at least one of the upper seat and the lower seat about an axis perpendicular to a direction of a lateral force generated when a parallel compressive load is applied to the compression coil spring; In a state in which the reaction force axis generated in the spring is held at an inclination angle when it is parallel to the center line of the seat surface connecting the center of the upper seat surface and the center of the lower seat surface of the compression coil spring, from the center line of the seat surface In the direction in which the body of the compression coil spring bulges in the direction opposite to the eccentric direction of the reaction axis, so that the body is curved until the reaction axis substantially matches the center line of the bearing surface. It is composed. Thus, when the thus formed compression coil spring is disposed between the upper seat and the lower seat, only at least one of the upper seat and the lower seat is inclined, and between them. When a compressive load is applied, the reaction axis coincides with the center line of the bearing surface.

Alternatively, as described in claim 2, a compression coil spring is interposed between the upper seat and the lower seat, and a direction of a lateral force when a parallel compression load is applied to the compression coil spring. The compression coil spring is arranged such that at least one of an upper seat surface and a lower seat surface of the compression coil spring is inclined with respect to the upper seat or the lower seat, respectively, about an axis perpendicular to the axis. A pitch in which at least one of the upper winding and the lower winding is set, and a reaction force axis generated in the compression coil spring connects the center of the upper bearing surface to the center of the lower bearing surface of the compression coil spring. At a tilt angle when parallel to the plane center line, at least one of the upper seat surface and the lower seat surface is inclined with respect to the upper seat or the lower seat, and the seat surface is inclined. A body of the compression coil spring on a side opposite to an eccentric direction of the reaction axis from a center line; In the direction of bulging, the configuration may be such that bending the body portion to the reaction force axis is substantially coincident with the bearing surface centerline. Thus, by simply interposing the compression coil spring thus formed between the upper and lower parallel seats, when a compressive load is applied between the two, the reaction force axis moves to the center of the seat surface. Will match the line.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a compression coil spring 2 according to an embodiment of the present invention, and an upper seat 3 shown by a two-dot chain line.
And the lower seat 4. This compression coil spring 2
The upper seat 3 and the lower seat 4 are centered on an axis perpendicular to the direction of a lateral force generated when a parallel compressive load is applied to the compression coil spring 2 between the upper seat 3 and the lower seat 4. 4 is inclined (for example, the lower seat 4), and the reaction force axis RA generated in the compression coil spring 2 is
The inclination angle (for example, the inclination angle of the upper seat 3) when it is parallel to a seat surface center line CL (coincident with the reaction force axis RA in FIG. β is 0 °
In the state where the lower seat 4 is held at the inclination angle α at the time of (1), the direction in which the body 2c bulges out on the opposite side to the eccentric direction of the reaction force axis RA from the seat surface center line CL (leftward in FIG. 1). ), The trunk portion 2c is curved until the reaction force axis RA substantially matches the seat surface center line CL (that is, until the state shown in FIG. 1 is reached).

As shown in FIG. 1, the coil axis CA of the compression coil spring 2 is formed to be curved at a predetermined curvature (radius of curvature R) in a free state. Has an initial torsion. The compression coil spring 2 is interposed between the above-described upper seat 3 and the lower seat 4 inclined at the inclination angle α, and when a parallel compression load is applied, the reaction force axis RA causes the seat surface to move. The spring operation is performed in a stable state without any lateral force or load eccentricity, which coincides with the center line CL. In this case, the lower seating surface L
The relationship between S and the lower seat 4 is relative. In FIG. 1, the lower seat 4 is horizontal, and the lower seat surface LS is inclined by a predetermined angle α. The contact surface of the lower seat 4 may be horizontal and the lower seat surface LS may be inclined by a predetermined angle α. This specific mode will be described later.

Next, the compression coil spring 2 having the above configuration
An example of a method for manufacturing the will be described. First, as a detection step, FIG. 2 shows a model compression coil spring (represented by 2x).
As shown, a compression coil spring 2x is interposed between an upper seat (not shown) and a lower seat (not shown), and a coil shaft (normally, the center of the upper seat surface US and the lower seat). A parallel compression load is applied along the center line CL of the bearing surface LS connecting the center of the surface LS, and the direction of the lateral force F generated thereby is detected. At this time, the reaction force axis RA is eccentric as shown by the one-dot chain line in FIG. 2 (the amount of eccentricity is represented by e). In FIG. 3,
The direction of the lateral force F in the plan view is indicated by an arrow, and is represented by an angle θ.

Subsequently, the process proceeds to a holding process, in which, for example, the lower seating surface LS is centered on an axis (indicated by TA in FIGS. 2 and 3) perpendicular to the direction of the lateral force F detected in the detecting process. As shown in FIG. 4, it is rotated and driven to be inclined. Then, the reaction force axis CA generated in the compression coil spring 2x is maintained at the inclination angle (α) when it becomes parallel to the seat surface center line CL as shown in FIG.

Next, the process proceeds to the bending amount detecting step of FIG. 6 and, in a state where the lower seating surface LS is inclined in the holding step, the eccentric direction of the reaction force axis RA from the seating center line CL (FIG. 5). In the direction in which the body of the compression coil spring 2x bulges to the opposite side (to the left in FIG. 5), until the reaction force axis RA substantially coincides with the center line CL of the bearing surface. The amount of bending (the amount of body bending d shown in FIG. 6) is detected.

On the basis of the detection result of the above-described bending amount detecting step, in the coil processing step, the compression coil spring 2x is formed by a coiling machine (not shown) so as to form the body bending amount d. . That is, an NC device (not shown) previously sets the body bending amount d together with the pitch, coil diameter, and the like in a program, and the coiling machine is driven according to the program.

FIG. 7 shows a state in which the compression coil spring 2x is compressed in parallel as shown in FIG. 2, and the lower seat surface LS is centered on an axis perpendicular to the direction of the lateral force F as shown in FIG. FIG. 7 shows the change in the spring reaction force axis when the inclination angle α is increased and the inclination angle α is increased. A plurality of spring reaction forces corresponding to the change in the inclination angle α (the arrow in FIG. 7 indicates the increasing direction). The axis is indicated by a broken line, and the reaction force axis RA parallel to the solid line center line CL of the solid line at the point 0 is indicated by an alternate long and short dash line. The inclination angle α of the lower bearing surface LS that generates the load eccentricity of the reaction force axis RA indicated by the dashed line is shown in FIG.
As shown in FIG. FIG. 8 shows the load eccentricity e generated on the upper seat surface US and the lower seat surface LS according to the inclination angle α of the lower seat surface LS, and the broken line indicates the upper seat surface US and the solid line indicates the lower side. It shows the seat surface LS. FIG. 9 shows the relationship between the inclination angle α of the lower seating surface LS and the generated lateral force F. As is apparent from FIG.
When the inclination angle α is approximately 5 °, the lateral force F is minimized.

FIG. 10 shows the position of the reaction force axis by the load eccentricity e, and the reaction force axis RA indicated by the dashed line is indicated by the right arrow in accordance with the increase in the amount of bending (the amount of body bending d). The load eccentricity e approaches zero. FIG. 11 shows a change in the load eccentricity e according to the bending amount (d). The absolute value of the load eccentricity e decreases as the bending amount (d) increases, and the predetermined bending amount ( In this example, d = 1.1 mm), and the reaction axis substantially coincides with the spring center line CL (shown by a solid line) at the zero point position. After all, in the examples shown in FIGS. 7 to 11, if the inclination angle α is 5 ° and the amount of bending (d) is 1.1 mm, the lateral force becomes 0.
, The load eccentricity becomes zero.

The compression coil spring 2 constructed as described above
Since neither lateral force nor load eccentricity occurs, for example, FIG.
2 is suitable as a suspension coil spring for a double wishbone type suspension. First, the suspension device will be briefly described. The wheels WL are swingably supported by an upper arm UA and a lower arm LA, and are supported by a vehicle body (not shown) via a shock absorber 1. The compression coil spring 2 is mounted, and the basic configuration is the same as the conventional one.

In the double wishbone type suspension having such a configuration, it is desirable that the lateral force in the direction orthogonal to the axis of the shock absorber 1 is zero, and the lateral force by the compression coil spring 2 is suppressed as much as possible. The compression coil spring 2 of the present embodiment is configured as described above, and for example, as in FIG.
If S is inclined by a predetermined angle α, the lateral force and the load eccentricity can be substantially suppressed to values close to 0, so that it is suitable as a suspension coil spring.

Next, another embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In the above-described embodiment, the upper seat surface US and the lower seat surface LS of the compression coil spring 2 are not formed to be inclined, and at least one of the upper seat 3 and the lower seat 4 is arranged to be inclined. Is configured as
The present invention can be configured as follows as another embodiment. Hereinafter, with reference to FIG. 1, a description will be given focusing on differences from the above-described embodiment.

That is, the compression coil spring according to the present embodiment has less upper seat surface US and lower seat surface LS in FIG. 1 than an upper seat or a lower seat (not shown) arranged in parallel. The pitch of at least one of the upper end turn 2a and the lower end turn 2b is set so that either one of them is inclined, and the reaction force axis RA generated in the compression coil spring 2 is located between the center of the upper seat surface US and the lower end. An inclination angle (for example, an inclination angle β of the upper seat surface US) when it is parallel to a seat surface center line CL connecting the centers of the side seat surfaces LS.
At an inclination angle α of the lower seating surface LS when 0 is 0 °, at least one of the upper seating surface US and the lower seating surface LS is inclined with respect to the upper seat or the lower seat, Seat center line CL
The body 2c is curved in the direction in which the body 2c of the compression coil spring 2 bulges in the direction opposite to the eccentric direction of the reaction axis RA from the body 2c until the reaction axis RA substantially coincides with the seat surface center line CL. It is a thing.

In short, the compression coil spring according to another embodiment of the present invention is configured such that at least one of the upper seat surface and the lower seat surface is inclined with respect to the upper seat or the lower seat. The pitch of at least one of the winding 2a and the lower end winding 2b is set, and has an initial bending of the bending amount d. Thus, the compression coil spring of the present embodiment is interposed between the upper seat (not shown) and the lower seat (not shown) parallel to the upper seat (not shown), and when a parallel compression load is applied. ,
The reaction force axis coincides with the center line of the bearing surface, and the spring operation is performed in a stable state without any lateral force or load eccentricity.

Next, a method of manufacturing a compression coil spring according to another embodiment having the above configuration will be described. First, as a detection step, an upper seat (not shown) as in FIG.
And a lower seat (not shown), a compression coil spring 2x is interposed, a parallel compression load is applied along the coil axis CA, and the direction (θ) of the lateral force F generated thereby is detected. You. At this time, the reaction axis RA is eccentric as shown by the dashed line in FIG.

Subsequently, the process proceeds to an end-turn setting process, in which at least one of the upper seat surface US and the lower seat surface LS of the compression coil spring 2x is centered on an axis perpendicular to the direction of the lateral force detected in the detection process. The pitch of at least one of the upper end turn and the lower end turn of the compression coil spring 2x is set so that one is inclined with respect to the upper seat or the lower seat, respectively.

Further, the process proceeds to the bending amount detecting step, and the upper seat surface US and the lower seat surface LS are set at the inclination angle when the reaction force axis RA generated in the compression coil spring 2x becomes parallel to the seat surface center line CL. The body of the compression coil spring 2x bulges out in a state opposite to the eccentric direction of the reaction force axis RA from the seat surface center line CL with at least one of them inclined with respect to the upper seat or the lower seat. In this direction, the trunk is curved until the reaction force axis RA substantially coincides with the seat surface center line CL, and the amount of curvature (the amount of trunk bending d) is detected.

In the coil machining step, based on the detection result of the above-mentioned bending amount detection step and the setting result of the end turn setting step, a coiling machine (not shown) according to a program according to a program. The pitch of the upper end turn and / or the lower end turn is set so that an inclination angle (for example, α) of the surface is formed, and the body bending amount d
Is formed so as to form the body. Thus, a compression coil spring having a torso portion curved by the amount of curvature (torso bending amount d) of the detection result and having an upper seat surface and / or a lower seat surface inclined by a set inclination angle (α). Is formed.

FIG. 13 shows the valve train of an internal combustion engine. The compression coil spring provided for this valve has a lateral force of 0, similarly to the compression coil spring provided for the aforementioned double wishbone type suspension. It is desirable. FIG.
3, a valve stem (intake valve or exhaust valve) mounted on the internal combustion engine EG has a valve stem 10a slidably supported by a stem guide SG, and the valve stem 1
A retainer 13 is fixed to the tip of Oa, and is disposed so as to be pressed against the cam 11 via a valve lifter 14. A spring seat 15 is arranged on the internal combustion engine EG around the stem guide SG, and a compression coil spring 12 is interposed between the spring seat 15 and the retainer 13, and the valve 10 is operated by the compression coil spring 12. It is urged in the direction of the cam 11.

In the valve train of the internal combustion engine configured as described above, it is necessary to minimize the sliding resistance between the valve stem 10a and the stem guide SG. In this case, for example, described as another embodiment of the present invention,
The pitch of at least one of the upper end turn and the lower end turn is set so that at least one of the upper seat surface and the lower seat surface is inclined with respect to the upper seat or the lower seat. And a compression coil spring having an initial bending (12 in FIG. 13).
) Are used. Thus, when a parallel compressive load is applied between the retainer 13 and the spring seat 15,
The reaction force axis of the compression coil spring 12 coincides with the center line of the bearing surface, and no lateral force or load eccentricity occurs, the sliding resistance between the valve stem 10a and the stem guide SG is suppressed, and the valve 10 Is opened and closed. Further, the diameter of the stem guide SG can be reduced.

[0030]

The present invention has the following effects because it is configured as described above. That is, when the compression coil spring curved as described in claim 1 is disposed between the upper seat and the lower seat, only at least one of the upper seat and the lower seat is inclined, When a compressive load is applied between the two, the reaction force axis coincides with the center line of the bearing surface, so that the support can be appropriately performed without any lateral force or load eccentricity. Moreover, since the stress can be easily designed without depending on the winding number design, the suspension coil spring for the double wishbone type suspension,
It is suitable for a coil spring or the like of a valve train.

Further, in the case of the structure as described in claim 2, the curved compression coil spring is simply interposed between the parallel upper and lower seats, and the compression load is applied between the two. Is applied, the reaction force axis coincides with the center line of the bearing surface, so that it is possible to appropriately support without generating any lateral force or load eccentricity. Therefore, when mounting on a suspension coil spring for a double wishbone type suspension, a coil spring of a valve operating system, or the like, there is no need to change them, so that the present invention can be easily applied.

[Brief description of the drawings]

FIG. 1 is a front view showing a compression coil spring according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which a model compression coil spring of the present invention is compressed in parallel.

FIG. 3 is a plan view showing a state of a lower seat surface when a model compression coil spring of the present invention is compressed in parallel.

FIG. 4 is a front view showing a state where the lower seating surface is inclined in a state where the model compression coil spring of the present invention is compressed in parallel.

FIG. 5 is a perspective view showing a state in which the lower bearing surface is inclined with the model compression coil spring of the present invention compressed in parallel.

FIG. 6 is a perspective view showing a state where the model compression coil spring of the present invention is parallel-compressed, the lower seating surface is inclined, and the trunk is further curved.

7 is a graph showing a change in a spring reaction force axis when the lower bearing surface is inclined in a state where the compression coil spring of FIG. 2 is compressed in parallel.

8 is a graph showing the amount of load eccentricity generated on the upper seat surface and the lower seat surface when the lower seat surface is inclined in a state where the compression coil spring of FIG. 2 is compressed in parallel.

9 is a graph showing a relationship between an inclination angle and a lateral force when the lower bearing surface is inclined in a state where the compression coil spring of FIG. 2 is compressed in parallel.

10 shows a reaction force corresponding to the amount of bending (the amount of body bending d) when the lower part of the seat is inclined while the compression coil spring of FIG. 2 is compressed in parallel, and the body is further bent. It is a graph which shows the position of an axis.

11 is a diagram showing a change in the load eccentricity according to the amount of bending (d) when the lower bearing surface is inclined while the compression coil spring of FIG. 2 is parallel-compressed and the trunk is further bent. FIG.

12 is a perspective view showing an example of a double wishbone type suspension to which the compression coil spring of FIG. 1 is applied.

FIG. 13 is a sectional view showing an example in which a compression coil spring according to another embodiment of the present invention is applied to a valve train of an internal combustion engine.

[Explanation of symbols]

2 compression coil spring, 3 upper seat, 4 lower seat,
CA coil axis, RA reaction axis, CL seat center line,
US Upper seat, LS Lower seat

Claims (2)

[Claims] 1. A compression coil spring is interposed between an upper seat and a lower seat, and a center is set about an axis perpendicular to a direction of a lateral force generated when a parallel compression load is applied to the compression coil spring. To
At least one of the upper seat and the lower seat is inclined, and a reaction force axis generated in the compression coil spring connects a center of the upper seat surface to a center of the lower seat surface of the compression coil spring. While maintaining the inclination angle when it becomes parallel to the line,
In the direction in which the body of the compression coil spring bulges in a direction opposite to the eccentric direction of the reaction force axis from the seat surface center line, the body portion until the reaction force axis substantially matches the seat surface center line. A compression coil spring formed by bending. 2. A compression coil spring is interposed between an upper seat and a lower seat, and a center is formed about an axis perpendicular to a direction of a lateral force when a parallel compression load is applied to the compression coil spring. The upper and lower end turns of the compression coil spring are arranged such that at least one of the upper and lower seating surfaces of the compression coil spring is inclined with respect to the upper and lower seats, respectively. When at least one pitch is set, the reaction force axis generated in the compression coil spring is parallel to a seat surface center line connecting the center of the upper seat surface and the center of the lower seat surface of the compression coil spring. At an inclination angle, in a state where at least one of the upper seat surface and the lower seat surface is inclined with respect to the upper seat or the lower seat, the reaction force axis from the seat surface center line is In the direction in which the body of the compression coil spring bulges out on the opposite side to the eccentric direction, the reaction force axis is A compression coil spring in which the body is curved until it substantially coincides with the center line of the seat surface.