阅读说明：本技术 一种单边变节距气门弹簧及其绕制工装、方法 (Unilateral variable-pitch valve spring and winding tool and method thereof ) 是由 陈华健 朱文奇 郝国华 蔡栋 李斌 侯世玉 胡健 于 2020-05-22 设计创作，主要内容包括：本发明提供一种单边变节距气门弹簧及其绕制工装、方法,所述弹簧本体沿轴向自上而下包括顶端并圈、等节距圈、过渡圈、变节距圈以及底端并圈；所述变节距圈的节距小于等节距圈的节距,并通过所述过渡圈均匀过渡；从所述顶端并圈到等节距圈四分之一处,弹簧的外径逐渐变大,且最大值小于底端并圈的弹簧内径。本发明在弹簧绕制的过程中,通过控制节距销和绕制销的运动改变弹簧的节距和外径,形成单边变节距的外部轮廓,减小弹簧上端部的外径、增加弹簧本体的自振频率,实现轻量化的同时避免了在高转运速下发生颤振,装配时易于区分,减少装配错误。(The invention provides a unilateral variable-pitch valve spring and a winding tool and method thereof.A spring body comprises a top end parallel ring, an equal-pitch ring, a transition ring, a variable-pitch ring and a bottom end parallel ring from top to bottom along the axial direction; the pitch of the variable-pitch ring is smaller than that of the equal-pitch ring, and the variable-pitch ring is uniformly transited through the transition ring; from the top end doubling up to the quarter of the equal pitch circle, the outer diameter of the spring is gradually increased, and the maximum value is smaller than the inner diameter of the spring which is doubled up at the bottom end. In the process of winding the spring, the pitch and the outer diameter of the spring are changed by controlling the movement of the pitch pin and the winding pin, so that the outer profile with a single-side variable pitch is formed, the outer diameter of the upper end part of the spring is reduced, the natural vibration frequency of the spring body is increased, the vibration is avoided at a high transfer speed while the light weight is realized, the assembly is easy to distinguish, and the assembly error is reduced.)

1. The utility model provides a unilateral variable pitch valve spring, includes the spring body, its characterized in that:

the spring body comprises a top end parallel ring (1), an equal pitch ring (2), a transition ring (3), a variable pitch ring (4) and a bottom end parallel ring (5) from top to bottom along the axial direction;

the pitch of the variable-pitch ring is smaller than that of the equal-pitch ring, and the variable-pitch ring is uniformly transited through the transition ring;

from the top end doubling up to the quarter of the equal pitch circle, the outer diameter of the spring is gradually increased, and the maximum value is smaller than the inner diameter of the spring which is doubled up at the bottom end.

2. A single-sided variable pitch valve spring according to claim 1, wherein said spring body satisfies the following relationship:

De1-Di2<1.5d；De1-Di2>0

where De1 is the spring top outer diameter, Di2 is the spring bottom inner diameter, and d is the spring wire diameter.

3. A single-sided variable pitch valve spring according to claim 1, wherein the pitch of the equal pitch ring (2) is 7.5-8.0mm, the pitch of the transition ring (3) is 4.5-7.5mm, and the pitch of the variable pitch ring (4) is 4.0-4.5 mm.

4. A single-sided variable-pitch valve spring according to claim 1, wherein the top-end parallel winding and the bottom-end parallel winding are respectively set to be one winding, the equal-pitch winding (2) accounts for 30% of the total number of turns of the spring, the transition winding (3) accounts for 10% of the total number of turns of the spring, and the variable-pitch winding (4) accounts for about 40% of the total number of turns of the spring.

5. A winding tool based on the unilateral variable-pitch valve spring according to any one of claims 1-4, and is characterized by comprising a feeding mechanism and a winding mechanism, wherein the feeding mechanism comprises a guide plate (6) for straightening and limiting and at least one group of feeding rollers (7) arranged on two sides of the guide plate, and the feeding rollers are used for feeding wire raw materials into the winding mechanism; the winding mechanism comprises a tool apron (8), a pitch pin (9) and at least two winding pins (10), wherein the pitch pin and the winding pins can move under the action of a driving device.

6. A winding method of a single-side variable-pitch valve spring based on any one of claims 1 to 4 is characterized by comprising the following steps:

setting target values of the pitch and the outer diameter winding of the spring;

the wire raw material is fed into the winding mechanism through a feeding roller and a guide plate;

the winding mechanism adjusts the movement of the pitch pin and the winding pin according to the target value, and controls the pitch and the outer diameter of the spring to be wound, so that the spring is wound and molded.

Technical Field

The invention relates to the technical field of spring manufacturing, in particular to a unilateral variable-pitch valve spring and a winding tool and method thereof.

Background

Disclosure of Invention

In order to solve the problem that the common cylindrical equal-pitch valve spring is easy to vibrate under the condition of high rotating speed so as to cause the phenomenon of spring fracture failure in the prior art, the structure and the process of the spring need to be improved, and the valve spring with good damping effect is provided.

In order to achieve the purpose, the invention adopts the following technical scheme:

a single-side variable-pitch valve spring comprises a spring body, wherein the spring body comprises a top end parallel ring, an equal pitch ring, a transition ring, a variable pitch ring and a bottom end parallel ring from top to bottom along the axial direction; the pitch of the variable-pitch ring is smaller than that of the equal-pitch ring, and the variable-pitch ring is uniformly transited through the transition ring; from the top end doubling up to the quarter of the equal pitch circle, the outer diameter of the spring is gradually increased, and the maximum value is smaller than the inner diameter of the spring which is doubled up at the bottom end.

Further, the spring body satisfies the following relation:

De1-Di2<1.5d；De1-Di2>0

where De1 is the spring top outer diameter, Di2 is the spring bottom inner diameter, and d is the spring wire diameter.

Preferably, the pitch of the equal-pitch ring is 7.5-8.0mm, the pitch of the transition ring is 4.5-7.5mm, and the pitch of the variable-pitch ring is 4.0-4.5 mm.

Preferably, the top end parallel winding and the bottom end parallel winding are respectively set to be one winding, the equal pitch winding accounts for 30% of the total number of turns of the spring, the transition winding accounts for 10% of the total number of turns of the spring, and the variable pitch winding accounts for about 40% of the total number of turns of the spring.

A winding tool for a single-side variable-pitch valve spring comprises a feeding mechanism and a winding mechanism, wherein the feeding mechanism comprises a guide plate for straightening and limiting and at least one group of feeding rollers arranged on two sides of the guide plate, and the feeding rollers are used for feeding wire raw materials into the winding mechanism; the winding mechanism comprises a cutter holder, a pitch pin and at least two winding pins, and the pitch pin and the winding pins can move under the action of a driving device.

A winding method of a single-side variable-pitch valve spring specifically comprises the following steps:

setting target values of the pitch and the outer diameter winding of the spring;

the wire raw material is fed into the winding mechanism through a feeding roller and a guide plate;

the winding mechanism adjusts the movement of the pitch pin and the winding pin according to the target value, and controls the pitch and the outer diameter of the spring to be wound, so that the spring is wound and molded.

In the process of winding the spring, the pitch and the outer diameter of the spring are changed by controlling the movement of the pitch pin and the winding pin, so that the outer profile with a single-side variable pitch is formed, the outer diameter of the upper end part of the spring is reduced, the natural vibration frequency of the spring body is increased, the vibration is avoided at a high transfer speed while the light weight is realized, the assembly is easy to distinguish, and the assembly error is reduced.

Drawings

FIG. 1 is a schematic flow chart of the steps of the present invention;

FIG. 2 is a diagram of the number of turns of the spring versus the pitch according to the present invention;

FIG. 3 is a schematic structural view of a spring winding tool according to the present invention;

FIG. 4 is a flow chart of the steps of the spring winding method of the present invention;

FIG. 5 is a graph of spring height versus natural frequency for the present invention;

FIG. 6 is a graph showing the effect of comparative experiments according to examples of the present invention;

in the figure: 1. top end doubling; 2. a circle with equal pitch; 3. a transition ring; 4. a variable pitch ring; 5. bottom end doubling; 6. a guide plate; 7. a feeding roller; 8. a base; 9. a pitch pin; 10. and winding the pin.

Detailed Description

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

The unilateral variable-pitch valve spring shown in fig. 1 comprises a spring body, wherein the spring body comprises a top end parallel ring 1, an equal-pitch ring 2, a transition ring 3, a variable-pitch ring 4 and a bottom end parallel ring 5 from top to bottom along the axial direction; the pitch of the variable-pitch ring is smaller than that of the equal-pitch ring, and the variable-pitch ring is uniformly transited through the transition ring; from the top end doubling up to the quarter of the equal pitch circle, the outer diameter of the spring is gradually increased, and the maximum value is smaller than the inner diameter of the spring which is doubled up at the bottom end.

In order to avoid winding and safety of design, the spring body according to the preferred embodiment satisfies the following relation:

De1-Di2<1.5d；De1-Di2>0

where De1 is the spring top outer diameter, Di2 is the spring bottom inner diameter, and d is the spring wire diameter.

As shown in FIG. 2, the pitch of the equal pitch circle 2 is 7.5-8.0mm, the pitch of the transition circle 3 is 4.5-7.5mm, and the pitch of the variable pitch circle 4 is 4.0-4.5 mm. The top end parallel ring 1 and the bottom end parallel ring 5 are respectively set to be a circle, the equal pitch circle accounts for 30% of the total number of turns of the spring, the transition circle accounts for 10% of the total number of turns of the spring, and the variable pitch circle accounts for about 40% of the total number of turns of the spring. When the spring is compressed under stress, the variable pitch part is firstly compressed, the rigidity of the spring is not constant any more in a certain range but is obviously improved, and the natural vibration frequency of the spring is also obviously improved, so that the single-side variable pitch spring has a good damping effect.

The specific calculation formula of the natural vibration frequency of the spring is as follows:

wherein f is_eThe natural vibration frequency of the spring, D the wire diameter of the spring, n the effective number of turns, D the middle diameter of the spring, G the shear modulus and rho the density.

When the spring is stressed and compressed, the variable-pitch part is firstly compressed, the effective number of turns is reduced, and other parameters are unchanged, so that the natural vibration frequency of the spring is obviously improved, a good damping effect is achieved in the high-rotation-speed motion process of an engine, and the condition that the service life of the valve spring is reduced due to flutter is improved.

The winding tool for the unilateral variable-pitch valve spring shown in fig. 3 comprises a feeding mechanism and a winding mechanism, wherein the feeding mechanism comprises a guide plate 6 for straightening and limiting and at least one group of feeding rollers 7 arranged on two sides of the guide plate, and the feeding rollers are used for feeding wire raw materials into the winding mechanism; the winding mechanism comprises a tool holder 8, a pitch pin 9 and at least two winding pins 10, which can be moved by a drive.

In the winding process, two winding pins are generally adopted, after wire raw materials enter a winding mechanism through a feeding mechanism, the wire raw materials are wound into a circle through a cutter holder 8 and two winding pins 10 according to a three-point rounding theorem, the outer diameter of the circle is controlled by changing the positions of the two winding pins, a circle of continuous circle can be formed along with continuous feeding, and meanwhile, the pitch is controlled through the movement of a pitch pin 9.

The winding method of the single-side variable-pitch valve spring shown in fig. 4 specifically comprises the following steps:

s1, setting target values of the pitch and the outer diameter winding of the spring;

s2, feeding the wire raw material into a winding mechanism through a feeding roller and a guide plate;

and S3, the winding mechanism adjusts the movement of the pitch pin and the winding pin according to the target value, and controls the pitch and the outer diameter of the spring to wind and form the spring.

The specific effects of the single-side variable pitch spring of the present invention are explained as follows:

as shown in FIG. 5, in the process of compression, the variable pitch part of the unilateral variable pitch valve spring is compressed firstly, the free height is reduced continuously, the frequency of the point A is 420HZ, the frequency can be quickly improved to 691HZ at the point B, and the natural vibration frequency of the spring is improved by 64.5% through the design of the variable pitch, so that the condition that the service life is reduced due to flutter can be effectively avoided under the condition of high rotating speed.

By adopting a dynamic simulation test, the unilateral variable-pitch spring and the common equal-pitch spring are respectively compared under the same environment, and the dynamic performance of the unilateral variable-pitch spring at a high rotating speed (more than 5500 revolutions per minute) is still good and no obvious wave peak appears as can be seen from fig. 6; and the spring with the same pitch has obvious wave crest at 5800 turns, which is the phenomenon that the spring is combined due to flutter, elastic force and stress surge.

The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.