JP3816544B2 - Wave spring - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a wave spring used in various devices including, for example, a multi-plate clutch mechanism of an automatic transmission of an automobile.
[0002]
[Prior art]
In a multi-plate clutch mechanism of an automatic transmission such as an automobile, a spring is incorporated for returning a clutch plate or absorbing a shock when the clutch is engaged. Ring springs such as disc springs and wave springs were used for this spring, but conventional disc springs and wave springs are complete rings with no cut surface in the circumferential direction. This was due to stamping and molding by a press. For this reason, the material yield was extremely poor, which caused an increase in cost.
[0003]
As a means for solving the above problems, a spring (so-called wave spring) was developed in which a strip-shaped spring material was formed into a C shape, and peaks and valleys were alternately formed in the circumferential direction of the spring material. . Since this type of spring can use a strip-shaped spring material cut to an appropriate length, the material yield is remarkably improved as compared with a conventional press punching spring, but there are problems as described below. .
[0004]
[Problems to be solved by the invention]
In the conventional wave spring, like the wave spring 1 schematically shown in FIG. 13, the crests 2 and the troughs 3 are alternately formed, and an intermediate portion (spring) between the crests 2 and the troughs 3 is formed. The effective part 4) draws a gentle curve and continues to the peak part 2 and the valley part 3. In such a wave spring 1, the radii of curvature r of the crest 2 and trough 3 are considerably large.
[0005]
When the wave spring 1 is used, as shown in FIG. 14, a load is applied by a pair of mating parts 5 and 6 parallel to each other from the thickness direction of the wave spring 1. In this case, as the load increases, the length of the contact portion between one counterpart component 5 and the peak portion 2 increases, and the length of the contact portion between the other counterpart component 6 and the valley portion 3 also increases. The length of the spring effective portion 4 is relatively reduced. For this reason, the wave spring 1 exhibits a non-linear load-displacement characteristic as shown in FIG.
[0006]
For this reason, the conventional wave spring 1 has an extremely nonlinear characteristic more than necessary depending on the shape of the peak part 2 and the valley part 3 and may not satisfy the required load-displacement characteristic. It may not be suitable for practical use.
[0007]
Further, since the wave spring 1 is partially cut in the circumferential direction as shown in FIG. 16, the rigidity is discontinuous at both ends 7 and 8 in the circumferential direction as compared with the spring of a complete ring without a break. It has become. In addition, in the case of the wave spring 1 having a part cut in the circumferential direction, the spring effective portion 4 receives bending moments from both ends when the load is applied, whereas the spring effective portion 4 receives bending moments from both ends. Since such a bending moment does not occur in the vicinity of the portions 7 and 8, the load in the vicinity of the both end portions 7 and 8 becomes low, causing an imbalance in the load distribution on the circumference.
[0008]
For these reasons, the center of the resultant force of the reaction force of each peak 2 and the reaction force of each valley 3 may be eccentric from the center axis of the spring 1. When such an imbalance of load distribution occurs, when the wave spring 1 is used as, for example, a clutch plate biasing spring, the clutch operating hydraulic piston that biases the wave spring 1 is inclined with respect to the cylinder, and the piston In some cases, the movement was hindered, causing malfunction.
[0009]
Further, when the wave spring is displaced with a load applied, the spring tends to increase in circumference as it approaches the close contact state, so that the outer diameter usually increases in displacement. However, when the outer periphery of the wave spring is surrounded by the other parts and the outer periphery is constrained, the wave spring cannot be displaced in the radial direction even if the circumference of the wave spring is extended. Can only be displaced in the direction. For this reason, if there is no degree of freedom in the circumferential direction, the spring becomes stiff and a sudden load increase occurs, and in the worst case, the spring breaks.
[0010]
Therefore, the object of the present invention is to avoid the load-displacement characteristic of the wave spring from becoming an extremely nonlinear characteristic, to approximate the load distribution to be uniform, and to increase the circumferential length when the displacement amount is large. It is in providing the wave spring which can absorb.
[0011]
[Means for Solving the Problems]
The corrugated spring of the present invention developed to achieve the above object is formed of a flat spring material that is formed in an annular shape and cut at a part in the circumferential direction, and has an arcuate peak when viewed from the side. And arcuate troughs and linear spring effective parts connecting these crests and troughs are alternately provided in the circumferential direction of the spring material, and the radius of curvature inside the crest of the crest when no load is applied R1 is smaller than the height H1 of the peak and the radius of curvature R2 inside the valley is smaller than the depth H2 of the valley, the thickness of the spring material is t, and the radius of curvature inside the curve of the peak is R1, when the radius of curvature of the curved inner valley was R2, t ≦ R1 ≦ 5t, Ri t ≦ R2 ≦ 5t der, and with high mountain portion at a position closer to the circumferential ends of the spring member The height is made larger than the height of the peak portion at a position far from both ends in the circumferential direction. Further, in the present invention, the pitch between the peak portion and the valley portion located near the both circumferential ends of the spring material is made smaller than the pitch between the peak portion and the valley portion located far from both circumferential ends. Features.
[0012]
[Action]
The corrugated spring according to the first aspect of the present invention has an increase in the contact area between the mating component and the corrugated spring when a load is applied, as compared to the conventional corrugated spring, the peak and trough approach the edge. This prevents the reduction of the effective spring portion.
[0013]
Further, by setting R1 and R2 to be equal to or greater than the plate thickness t of the spring material, generation of excessive stress at the peak or valley is prevented .
[0015]
Further, in the wave spring according to claim 1 , the height of the crest at a position close to both ends in the circumferential direction (near the break of the spring) is higher than the height of the crest at a position far from both ends in the circumferential direction. As a result, the amount of displacement of the spring effective portion at both ends in the circumferential direction is increased when the spring is displaced by the mating part to compensate for the load drop near the break. Further, in the wave spring according to claim 2 , the density of the crests and troughs in the vicinity of the spring break increases, so that the load received at both ends in the circumferential direction is increased to balance the load distribution on the circumference. I try to take it.
[0016]
【Example】
A first embodiment of the present invention will be described below with reference to FIGS.
The wave spring 10 shown in FIG. 4 is composed of a flat spring material 11 whose planar shape forms an annular shape. The spring material 11 is a strip-shaped spring steel. As shown in FIGS. 1 to 3, the wave spring 10 includes an arcuate peak portion 15, an arcuate valley portion 16, and a linear shape connecting the peak portion 15 and the valley portion 16 when viewed from the side. The spring effective portions 17 are provided alternately in the circumferential direction of the spring material 11. The crests 15 and troughs 16 in the illustrated example are provided at substantially equal pitches in the circumferential direction of the spring material 11.
[0017]
As schematically shown in FIG. 1, the wave spring 10 has a curvature radius R 1 on the inner side of the peak portion 15 in an unloaded state that is smaller than the height H 1 of the peak portion 15 and the curvature of the valley portion 16. The inner radius of curvature R2 is smaller than the depth H2 of the valley 16. The spring effective portion 17 extends linearly in the tangential direction of the arc of the peak portion 15 and the arc of the valley portion 16.
[0018]
As shown in FIG. 2, the wave spring 10 is used in a state of being sandwiched between the counterpart parts 20 and 21 parallel to each other, but when the distance between the counterpart parts 20 and 21 is reduced and the load is increased. In order to prevent the contact area between the peak 15 and the valley 16 from increasing, the curvature radius R1 of the peak 15 and the curvature radius R2 of the valley 16 are set to be not more than 5 times the plate thickness t of the spring material 11.
[0019]
The broken line m in FIG. 1 shows the outline of a conventional wave spring. Compared with the conventional wave spring, the wave spring 10 of this embodiment has a crest 15 and a valley 16 that are edge-shaped, and the spring effective portion. 17 has no bulge. Thus, by approaching the shapes of the peak portion 15 and the valley portion 16 to the edge shape, the length of the spring effective portion 17 is prevented from decreasing when the load increases. As a result, the load-displacement characteristic can be prevented from becoming an extremely nonlinear characteristic. Such edge shapes of the peak portion 15 and the valley portion 16 have the same effect even in a complete ring-shaped wave spring having no cut in the circumferential direction.
[0020]
As the radii of curvature R1 and R2 of the peaks 15 and valleys 16 become smaller, the stresses at the peaks 15 and valleys 16 tend to increase. Taking this into consideration, both R1 and R2 are set to be equal to or greater than the plate thickness t of the spring material 11 according to the result of finite element analysis.
[0021]
As shown in FIG. 3, since the spring material 11 is cut at a part in the circumferential direction, the load distribution may become unbalanced in the vicinity of both circumferential ends 30 and 31 as it is. Therefore, in this embodiment, as shown in FIG. 5 as representative of one end portion 30, the height T1 of the peak portion 15a located near the end portion 30 is set to the height of the peak portion 15 located far from the end portion 30. The height is higher than T2. In this case, when the wave spring 10 is displaced with the distance between the mating parts 20 and 21 close, the deflection of the spring effective portion 17a in the vicinity of both circumferential ends 30 and 31 is the deflection of the spring effective portion 17 in the other part. Therefore, it is possible to compensate for a decrease in load in the vicinity of both circumferential ends 30 and 31.
[0022]
Thereby, the imbalance of the load distribution on the circumference can be reduced, and the center of the resultant force of the reaction force of each peak portion 15 and the reaction force of each valley portion 16 is located on the central axis of this spring 10. Therefore, for example, in a clutch energizing wave spring of a multi-plate clutch mechanism, the hydraulic piston that presses the spring is not inclined with respect to the cylinder, and the cause of the malfunction can be solved.
[0023]
As a means for eliminating the imbalance of the load distribution on the circumference, as shown in FIG. 6, the pitch between the peak portions 15b and the valley portions 16b located near the circumferential ends 30 and 31 of the spring material 11 is shown. Is made smaller than the pitch of the crests 15 and troughs 16 located far from the circumferential ends 30 and 31, thereby increasing the wave number per unit length near the ends 30 and 31 and reducing the load. You may make it supplement.
[0024]
In addition, as shown in FIG. 7, the circumferential end portions 30 and 31 of the spring member 11 can be relatively moved in the circumferential direction of the spring member 11 in a state where the end portions 30 and 31 overlap each other in the thickness direction. An escape portion 32 is provided. The escape portion 32 is formed by bending one end portion 30. By providing the escape portion 32, even when the outer peripheral side of the wave spring 10 is constrained, it is possible to absorb the elongation of the circumferential length due to the displacement of the spring 10 at both end portions 30, 31. The effects of the interference between 30 and 31 were also avoided, and smooth characteristics could be obtained.
[0025]
In addition, like the escape portion 32 shown in FIG. 8, a step is provided in the plate thickness of the both end portions 30, 31 by crushing so that the circumferential end portions 30, 31 of the spring material 11 can overlap each other. Thus, even in a state where both end portions 30 and 31 are overlapped, a degree of freedom may be provided in the circumferential direction.
[0026]
FIG. 9 shows another embodiment of the present invention. As schematically shown in FIG. 10, the wave spring 10 is provided with semicircular protrusions 50 and 51 on the crest 15 and the trough 16, respectively. The base and trough of the semicircular protrusion 50 of the crest 15 are provided. The base portion of the semicircular protrusion 51 of the portion 16 is connected by a linear spring effective portion 17.
[0027]
As shown in FIG. 11, the wave spring 10 is also used in a state of being sandwiched between the counterpart parts 20 and 21, but when the load is applied, the contact area between the peak portion 15 and the valley portion 16 increases with the load. In order to prevent the increase in the radius of curvature, the curvature radius R1 of the inner side of the peak portion 15 in the no-load state is made smaller than the height H1 of the peak portion 15 and the inner side of the valley portion 16 is bent. The radius of curvature R2 is smaller than the depth H2 of the valley portion 16, and the curvature radius R1 of the peak portion 15 and the curvature radius R2 of the valley portion 16 are set to be not more than five times the plate thickness t of the spring material 11.
[0028]
Also in this case, if the radii of curvature R1 and R2 of the peaks 15 and valleys 16 become too small, the stresses at the peaks 15 and valleys 16 increase. R1 and R2 are both equal to or greater than the plate thickness t of the spring material 11.
By adopting the semicircular protrusions 50 and 51 as described above, it becomes possible to more effectively avoid the decrease in the effective spring portion 17 when the load increases, and the load-displacement characteristic is brought close to a substantially linear characteristic. I was able to.
[0029]
The spring material 11 of this embodiment is also cut at a part in the circumferential direction, and as shown in FIG. 12, relief portions 32 similar to those of the above-described embodiment are provided at both circumferential ends 30 and 31 of the spring material 11. It is good to have. Further, for the purpose of eliminating the imbalance of the load distribution in the circumferential direction, the same structure as that of the embodiment shown in FIG. 5 or FIG. 6 is adopted.
[0030]
【The invention's effect】
According to the first aspect of the present invention, it is possible to suppress the load-displacement characteristic of the wave spring from becoming an extremely nonlinear characteristic. Moreover, since the strip-shaped spring material cut | disconnected suitably in length can be used, a material yield improves remarkably compared with what is manufactured by press punching. In addition, it is possible to avoid an excessive stress at the peaks and valleys, and a desired peak shape at the peaks and valleys can be obtained .
[0031]
Wave spring according to claim 2 and 請 Motomeko 1, the spring member can be brought close to uniform load distribution even broken in some circumferential direction.
[Brief description of the drawings]
FIG. 1 is a side view schematically showing a part of a wave spring according to an embodiment of the present invention.
2 is a side view showing a state in which a load is applied to the wave spring shown in FIG. 1; FIG.
FIG. 3 is a partial cross-sectional view of a wave spring showing an embodiment of the present invention.
4 is an overall plan view of the wave spring shown in FIG. 3; FIG.
FIG. 5 is a cross-sectional view of an end portion of a wave spring.
FIG. 6 is a plan view showing an example in which the pitches of the peak and valley portions of the wave spring are changed in the circumferential direction.
FIG. 7 is a sectional view showing a state in which both end portions of the wave spring are overlapped with each other.
FIG. 8 is a cross-sectional view showing a modification of both end portions of the wave spring.
FIG. 9 is a sectional view of a part of a wave spring showing another embodiment of the present invention.
10 is a side view schematically showing a part of the wave spring shown in FIG. 9; FIG.
11 is a side view showing a state in which a load is applied to the wave spring shown in FIG. 10;
12 is a cross-sectional view showing a state in which both end portions of the wave spring shown in FIG. 10 are overlapped.
FIG. 13 is a side view schematically showing a conventional wave spring.
14 is a side view showing a state in which a load is applied to the conventional wave spring shown in FIG. 13; FIG.
FIG. 15 is a diagram showing the relationship between the load and displacement of a conventional wave spring.
FIG. 16 is a plan view of a conventional wave spring.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Wave spring 11 ... Spring material 15 ... Mountain part 16 ... Valley part 17 ... Spring effective part 30, 31 ... Circumferential direction both ends 32 ... Escape part 50, 51 ... Semicircular protrusion

Claims (2)

It consists of a flat spring material that is formed in an annular shape and cut at a part in the circumferential direction.
Arc-shaped crests, arc-shaped troughs, and linear spring effective parts that connect these crests and troughs are alternately provided in the circumferential direction of the spring material when viewed from the side direction,
In addition, the radius of curvature R1 inside the peak of the peak in an unloaded state is smaller than the height H1 of the peak, and the radius of curvature R2 inside the curved of the valley is smaller than the depth H2 of the valley, the thickness t, the radius of curvature of the curved inner crest R1, when the curvature radius of the curved inner valley and R2, t ≦ R1 ≦ 5t, Ri t ≦ R2 ≦ 5t der, moreover circle of the spring member A wave spring characterized in that the height of a peak portion located at a position near both ends in the circumferential direction is made larger than the height of a peak portion located at a position far from both ends in the circumferential direction . It consists of a flat spring material that is formed in an annular shape and cut at a part in the circumferential direction.
Arc-shaped crests, arc-shaped troughs, and linear spring effective parts that connect these crests and troughs are alternately provided in the circumferential direction of the spring material when viewed from the side direction,
In addition, the radius of curvature R1 inside the peak of the peak in an unloaded state is smaller than the height H1 of the peak, and the radius of curvature R2 inside the curved of the valley is smaller than the depth H2 of the valley, the thickness t, the radius of curvature of the curved inner crest R1, when the curvature radius of the curved inner valley and R2, t ≦ R1 ≦ 5t, Ri t ≦ R2 ≦ 5t der, moreover circle of the spring member A wave spring characterized in that a pitch between peaks and valleys at positions close to both ends in the circumferential direction is smaller than a pitch between peaks and valleys at positions far from both ends in the circumferential direction .

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