JP2004278588A - Disc springs and lap disc springs and disc spring devices - Google Patents

Abstract

A disc spring device for supporting or pressing a support using a disc spring maintains a load characteristic of the disc spring for a long period of time.
The apparatus includes a base, a support, and a plurality of disc springs interposed between the base and the support. The contact surface 12 on the side of the base 10 that contacts the lowermost disc spring 20g and the contact surface 16 on the side of the support 19 that contacts the uppermost disc spring 20a are covered with a resin layer. In this disc spring device, since the contact surfaces 12, 16 are covered with the resin layer, the frictional resistance between the disc spring 20g and the contact surface 12 decreases, and the frictional resistance between the disc spring 20a and the contact surface 16 decreases. For this reason, wear of both is suppressed, and the load characteristics of the lap disc spring 20 can be maintained for a long period of time.
[Selection diagram] Fig. 1

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc spring and a stacked disc spring in which a plurality of disc springs are overlapped. The present invention also relates to a disc spring device using one or more disc springs.
[0002]
2. Description of the Related Art Disc springs can generate a large force with a small displacement in the load direction, and are used for various purposes. As a device using a disc spring, for example, devices disclosed in Patent Literature 1 and Patent Literature 2 are known.
In the disc spring device described in Patent Document 1, a plurality of disc springs are interposed between a foundation (base) and a building (support). The plurality of disc springs are stacked in the same direction, and the weight of the building acts. In this disc spring device, when the foundation is displaced in the vertical direction due to an earthquake or the like, the load acting on the disc spring also changes. For this reason, each disc spring is elastically deformed to absorb the relative displacement of the foundation relative to the building, thereby absorbing the vibration transmitted to the building.
The disc spring device described in Patent Document 2 includes a casing (base) and a cell stack (support) housed in the casing. The disc spring is interposed between the casing and the cell stack in a compressed state, and applies a force in a direction in which the cells of the cell stack adhere to each other.
[0003]
[Patent Document 1]
JP 2002-39244 A [Patent Document 2]
JP 2001-167745 A
In the above-described disc spring device, the disc spring interposed between the base and the support is designed to obtain a desired load characteristic, and the load characteristic is maintained for a long period of time. It is required to be maintained. However, conventionally, no detailed study has been made from the viewpoint of maintaining the load characteristics of the disc spring over a long period of time.
[0005]
An object of the present invention is to provide a technology that enables a load characteristic of a disc spring to be maintained for a long time in a disc spring device using the disc spring.
[0006]
In order to solve the above-mentioned problems, a coned disk spring device according to the present invention comprises a base, a support, and one or a plurality of members interposed between the base and the support. And two disc springs. Further, at least one of the contact surface on the substrate side that contacts the disc spring and the contact surface on the support that contacts the disc spring is covered with a different material layer.
In this disc spring device, at least one of the contact surface on the base side contacting the disc spring and the contact surface on the support side contacting the disc spring is coated with a different material layer different from the material of the disc spring, thereby forming the disc spring. The load characteristics are prevented from changing over time. That is, when the load acting on the disc spring changes due to an external force acting on the base or the support, or thermal deformation of the base or the support, the shape of the disc spring (that is, the inclination angle of the disc spring) changes. For this reason, during long-term use, the contact surfaces of the disc spring and the base side (or the support side) rub against each other, and both of them wear (for example, cohesive wear) to change the load characteristics. In this disc spring device, since the contact surface on the base side (or the contact surface on the support side) that comes into contact with the disc spring is covered with the different material layer, wear (particularly, adhesion wear) of both is suppressed. For this reason, the load characteristics of the disc spring can be maintained for a long time.
It is to be noted that both the contact surface on the base side contacting the disc spring and the contact surface on the support side contacting the disc spring may be coated with a different material layer. It can be determined according to the use and the mode of use.
When a plurality of disc springs are interposed between the base and the support, the contact surface between the disc springs may be covered with a different material layer (for example, a resin layer). Covering between the disc springs is more effective because wear between the disc springs can be suppressed.
[0007]
The different material layer can be, for example, a resin layer containing a polyamideimide resin as a main component. Further, it is preferable that a lubricant is mixed in the resin layer. When the lubricant is mixed, the frictional resistance between the two is further reduced, and the abrasion due to rubbing can be further suppressed.
Further, it is preferable that the different material layer is a film containing diamond-like carbon (DLC) as a main component.
[0008]
In the above-mentioned disc spring device, it is preferable that at least one of the corner of the disc spring contacting the contact surface on the base side and the corner portion of the disc spring contacting the contact surface on the support is chamfered or rounded. . If the corner of the disc spring is chamfered, the contact area between the disc spring and the contact surface increases, and the surface pressure decreases. For this reason, wear of both can be suppressed. Further, when the corner of the disc spring has an R-shape, the corner of the disc spring easily slides on the contact surface, so that wear of both can be suppressed.
[0009]
Further, the present application provides a disc spring capable of maintaining load characteristics for a long period of time. In the disc spring according to the present application, at least one of the two corners formed at both ends in the thickness direction of the inner diameter surface and the two corners formed at both ends in the thickness direction of the outer diameter surface is chamfered or rounded. It is characterized by having a shape.
With this disc spring, wear of a mating member that comes into contact with the disc spring (for example, a holding member that holds the disc spring) can be suppressed. As a result, the load characteristics of the disc spring can be maintained for a long time.
[0010]
Further, a stacked disc spring can be formed using the disc spring according to the present invention. That is, in one embodiment of the stacked disc spring according to the present application, the disc spring is a stacked disc spring in which a plurality of disc springs are stacked, and the disc spring is used as at least one of the disc springs disposed at both ends thereof. Can be
The contact surface between the disc springs is preferably covered with a resin layer in order to reduce the frictional resistance between them.
[0011]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A disc spring device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a view showing a schematic configuration of the disc spring device.
As shown in FIG. 1, the disc spring device according to the present embodiment includes a casing 10 and a cell stack 19 (for example, a cell stack such as a fuel cell) housed in the casing 10. A casing-side holder 11 is attached to a lower end (the lower side in the drawing) of the casing 10. The casing side holder 11 includes a holder body 13 fixed to the casing 10. A wall 14 is provided on the contact surface 12 of the holder body 13 according to the outer diameter of the disc springs 20a to 20g.
On the other hand, a cell-side holder 15 is attached to the lower end of the cell stack 19. The cell-side holder 15 includes a holder main body 17 fixed to one end surface (the lower end surface in the drawing) of the cell stack 19. A columnar leg 18 is provided from the contact surface 16 of the holder body 17. The outer diameter of the leg 18 is substantially the same as (slightly smaller than) the inner diameter of the disc springs 20a to 20g, and the leg 18 can be inserted into the central opening of the disc springs 20a to 20g.
[0012]
Between the casing-side holder 11 and the cell-side holder 15 described above, a plurality of disc springs 20a to 20g stacked in the same direction (hereinafter, a state in which the disc springs 20a to 20g are stacked is also referred to as a stacked disc spring 20). .) Is retained. That is, the leg 18 of the cell-side holder 15 is inserted into the center opening of each of the disc springs 20a to 20g, and the lowermost disc spring 20g is positioned by the wall 14 with respect to the holder body 13 on the casing side. Thereby, the laminated disc spring 20 is held between the casing-side holder 11 and the cell-side holder 15.
In a state where the stacked disc spring 20 is held, the disc spring 20a at the upper end contacts the contact surface 16 on the cell side, and the disc spring 20g at the lower end contacts the contact surface 12 on the casing. The stacked disc spring 20 is disposed between the casing 10 and the support 19 in a compressed state so that a force is generated in a direction of pressing the cell stack 19 (upward in the drawing).
Note that the number of disc springs constituting the stacked disc spring 20 can be appropriately determined so as to obtain a desired load characteristic, and the number is not limited to the example shown in FIG.
[0013]
In the above-mentioned disc spring device, it is preferable that the cell laminated body 19 is pressed with a substantially constant pressing force from the viewpoint of improving its characteristics. On the other hand, since the dimensions of the cell stack 19 during use change due to thermal displacement or the like, the amount of deflection of the disc springs 20a to 20g also changes. For this reason, it is preferable that the disc springs 20a to 20g can press the cell stack 19 with a substantially constant pressing force even if the amount of deflection changes. Therefore, in the present embodiment, a predetermined pressing force is applied to the cell stack 19 in an area where the amount of change in the “load” is small even if the “deflection amount” changes (an area where the load curve is horizontal in the graph of FIG. 5). The load characteristics and the initial displacement of the stacked disc spring 20 are determined so that the above-mentioned can be applied (see FIG. 5).
[0014]
When the amount of deflection of the disc springs 20a to 20g changes, the contact surfaces of the disc springs rub against each other, and the disc spring 20a at the upper end and the contact surface 16 on the cell side and the disc spring 20g at the lower end and the contact surface on the casing side. 12 rubs. Therefore, a difference (a so-called hysteresis loss) occurs between the “flexure amount-load curve” when the stacking disc spring 20 is pressurized and the “flexure amount-load curve” when the load is unloaded. From the viewpoint of pressurizing the cell stack 19 with a substantially constant pressing force, it is preferable that the hysteresis loss of the lap spring 20 be as small as possible, and that the state in which the hysteresis loss is small be maintained for a long period of time.
[0015]
Therefore, in this embodiment, the surface treatment described below is applied to the contact surface 16 on the cell side and the contact surface 12 on the casing side. That is, the contact surfaces 16 and 12 are first polished (for example, buffed or the like), and then coated with a different material layer different from the material of the disc springs 20a to 20g. As a result, the frictional resistance between the stacked disc spring 20 and the contact surfaces 12 and 16 is reduced, and the hysteresis loss of the stacked disc spring 20 is reduced.
[0016]
In the polishing process performed on the contact surfaces 12 and 16, it is preferable that the surface roughness of the contact surfaces 12 and 16 be in the range of Rmax 0.5 to 5.0. If Rmax is less than 0.5, the time (time, etc.) of the polishing process is too long, which is not preferable. If Rmax is more than 5.0, the hysteresis is not sufficiently reduced. More preferably, Rmax is preferably in the range of 1.0 to 2.0 (for example, about Rmax 1.6). Further, it is preferable that the flatness of the contact surfaces 12, 16 is about 0.1 or less.
[0017]
For the treatment for covering the contact surfaces 12 and 16 with the different material layer, a film treatment for applying a resin solution can be used. As a resin solution to be applied, for example, a resin solution containing a polyamideimide resin, an epoxy resin, a phenol resin, or the like as a main component can be used. Further, it is preferable to mix a lubricant (for example, a resin-based lubricant such as fluororesin (PTFE) or PE, or a lubricant such as graphite or molybdenum disulfide) into the resin solution. The particle size of the lubricant to be mixed is preferably smaller than 1 μm.
As a method for providing a resin film, a dry film treatment can be used. In the dry film treatment, for example, first, oil and dirt are removed from the surfaces of the contact surfaces 12 and 16, then a resin solution mixed with a lubricant is applied, and then the applied solution is dried and finally dried. The heat treatment (200 to 300 ° C.) of the coated film can be performed. Spraying, spray tumbling, and brush coating can be used as a method of applying. The thickness of the resin film provided by such a treatment is preferably about 15 μm (for example, 5 to 25 μm). The reason why the thickness of the film is set to about 15 μm is to maintain the effect of the film over a long period of time.
[0018]
In addition to the above, as a different material layer covering the contact surfaces 12 and 16, for example, a film containing diamond-like carbon (DLC) as a main component, a nitriding treatment, a Liubrite treatment, a molybdenum disulfide treatment, or the like. And a film obtained by various plating processes (for example, electroless Ni plating, electroless Ni-P composite plating, chromium plating, etc.) can be preferably used. It is preferable that a lubricant is mixed in the film provided by such a surface treatment. As the lubricant to be mixed, for example, the above-mentioned PTFE or the like can be used.
[0019]
Further, a smoothing process described below is performed on the corner of the disc spring 20g that contacts the contact surface 12 and the corner of the disc spring 20a that contacts the contact surface 16 described above. As shown in FIG. 2, each of the disc springs 20a to 20g has a donut shape with an opening formed in the center, and its peripheral surface has an inclined surface. With regard to the disc spring 20g, the corner 25 of the outer edge 24 that comes into contact with the contact surface 12 is subjected to a smoothing process. With regard to the disc spring 20a, a smoothing process is performed on the corner portion 22 of the inner edge 21 that is in contact with the contact surface 16.
[0020]
3 and 4 show an example of the smoothing process performed on the corner 25 of the disc spring 20g. In the example shown in FIG. 3, the corner 25 of the disc spring 20g is formed into an R shape. By processing the corner 25 into an R shape, it is possible to suppress a phenomenon (a so-called peeling phenomenon) in which a film of the contact surface 12 is scraped off by the corner 25 when the corner 25 and the contact surface 12 rub against each other. As a result, the hysteresis characteristics of the stacked disc spring 20 can be maintained for a long period of time.
In the example shown in FIG. 4, the corner 25 of the disc spring 20g is chamfered. By chamfering the corner 25, the contact area between the disc spring 20g and the contact surface 12 increases, so that the contact surface pressure decreases. Therefore, the frictional resistance when the corner 25 and the contact surface 12 rub against each other is reduced, and the wear of the coating on the contact surface 12 can be suppressed. Even with such a method, the hysteresis characteristics of the lap disc spring 20 can be maintained for a long time.
As for the smoothing process performed on the corner portion 22 of the disc spring 20a, the same process as the above-described smoothing process performed on the corner portion 25 of the disc spring 20g can be performed.
[0021]
The above-described smoothing process is performed on the corners formed at the upper end in the thickness direction of the inner diameter surface and the corners formed at the lower end in the thickness direction of the outer diameter surface for each of the disc springs 20a to 20g. It may be. With such a configuration, all the disc springs 20a to 20g have the same configuration, and may be superposed in any order.
Further, depending on the shape of the holder for holding the disc spring, the corner formed at the lower end in the thickness direction of the inner diameter surface of the disc spring and the corner formed at the upper end in the thickness direction of the outer diameter surface may also rub against the holder. In such a case, it is preferable to perform the above-described smoothing processing also on these corners.
[0022]
In addition, it is preferable that the same treatment as the surface treatment applied to the contact surfaces 12 and 16 is applied to the contact surfaces of the respective plate springs of the respective disc springs 20a to 20g constituting the stacked disc spring 20. That is, by performing the above-described surface treatment on the upper surface (the surface indicated by 26 in FIG. 2) and / or the bottom surface (the surface indicated by 27 in FIG. 2), the frictional resistance between the disc springs is reduced. Therefore, the hysteresis loss of the stacked disc spring can be reduced.
[0023]
EXPERIMENTAL EXAMPLE Next, the above-described disc spring device was actually manufactured, and the relationship between hysteresis loss and durability was examined. In the experiment, five disc springs having an outer diameter of 200 mm, an inner diameter of 110 mm, and a plate thickness of 3.7 mm were superposed to form a laminated disc spring. The surface roughness of the contact surface of each disc spring was Rmax 1.6, and each contact surface was coated with a film (about 15 μm) in which PTFE was dispersed in polyamideimide resin. The two corners that come into contact with the holder (ie, the upper end corner of the inner diameter surface of the disc spring at the upper end and the lower end corner of the outer diameter surface of the lower disc spring) have two R shapes. One type (R radius 0.23 mm, 0.76 mm), one subjected to chamfering, and one type as a comparative example (prior art) without R-shape or chamfering were produced.
As for the holder, one kind in which the contact surface of the holder is subjected to a polyamideimide resin-based surface treatment (film 15 μm, additive; PTFE + graphite), and a comparative example (conventional technology) in which the contact surface of the holder is subjected to a surface treatment One type that was not applied was produced.
With respect to the various combinations of the manufactured disc springs and holders, elastic deformation was repeatedly applied with a predetermined stroke (4 mm) from the state where the initial load was applied, and the relationship between the number of elastic deformations and the hysteresis loss was examined.
[0024]
FIG. 6 shows an experimental result of a laminated disc spring having a rounded corner portion and a conventional laminated disc spring. In each of the experiments, a holder according to the prior art in which the contact surface was not subjected to a surface treatment was used. As is clear from FIG. 6, the laminated disc spring having the R-shaped corner portion was able to suppress an increase in the hysteresis loss for a long period of time as compared with the case where the R-shaped spring was not formed. In addition, the R shape applied to the corners showed better results as the radius of curvature increased.
[0025]
FIG. 7 shows an experimental result of a laminated disc spring having a chamfered corner portion and a conventional laminated disc spring. In each of the experiments, a holder according to the prior art in which the contact surface was not subjected to a surface treatment was used. As is clear from FIG. 7, the overlapped disc spring with the chamfered corner portion was able to suppress an increase in hysteresis loss for a longer period of time as compared with the case without the chamfered process.
[0026]
FIG. 8 shows experimental results of a holder having a contact surface subjected to a surface treatment and a holder according to the related art. In each of the experiments, the lap springs according to the prior art, in which the corners were not rounded or chamfered, were used. As is clear from FIG. 8, the holder in which the contact surface was subjected to the surface treatment was able to suppress an increase in the hysteresis loss as compared with the case where the surface treatment was not performed.
[0027]
FIG. 9 shows a case where a laminated disc spring having a corner portion having an R shape (R; 0.76 mm) is held by a holder whose surface is subjected to a surface treatment on the contact surface, and a case where the laminated disc spring according to the prior art is placed on the contact surface. Experimental results are shown for a case where the holder is treated with a treated holder and for a case where the lap spring according to the prior art is held by a holder according to the related art. As is evident from FIG. 9, when the overlapping disc spring having an R-shaped corner is held by a holder having a contact surface subjected to a surface treatment, the hysteresis is the smallest, and the best result is obtained for the durability. Was.
[0028]
As mentioned above, although the specific example of this invention was demonstrated in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and alterations of the specific examples illustrated above.
Further, the technical elements described in the present specification or the drawings exhibit technical utility singly or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.
[Brief description of the drawings]
FIG. 1 is a diagram showing a structure of a disc spring device according to an embodiment.
FIG. 2 is a sectional view of a disc spring.
FIG. 3 is a diagram illustrating an example of a smoothing process performed on a corner of a disc spring.
FIG. 4 is a diagram showing another example of the smoothing process performed on the corners of the disc spring.
FIG. 5 is a view showing load characteristics (hysteresis characteristics) of the lap disc spring.
FIG. 6 is a view additionally showing the relationship between the measured hysteresis and the number of endurance times for a stacked disc spring having an R-shaped corner portion and a conventional stacked disc spring.
FIG. 7 is a view additionally showing the relationship between the measured hysteresis and the number of endurance times for a laminated disc spring having a corner portion subjected to chamfering and a conventional laminated disc spring.
FIG. 8 is a diagram also showing the relationship between the actually measured “hysteresis and the number of endurance times” when a holder having a surface treated on a contact surface is used and when a holder according to the related art is used.
FIG. 9 shows a case where a laminated disc spring having a corner portion having an R shape (R; 0.76 mm) is held by a holder whose surface is subjected to a surface treatment on a contact surface, and a case where a laminated disc spring according to a conventional technique is surface treated on a contact surface. FIG. 11 is a diagram additionally showing the relationship between the actually measured “hysteresis and the number of endurance times” in the case of holding with the holder according to the related art and the case of holding the laminated disc spring according to the related art with the holder according to the related art.
[Explanation of symbols]
10: Casing 11: Casing-side holder 12: Side contact surface 13: Holder body 14; Wall 15: Cell-side holder 16: Contact surface 17: Holder body 18: Leg 19: Cell stack 20: Stacked disc springs 20a to 20g : Disc springs 22, 25: Corner

Claims (7)

A base, a support, and one or more disc springs interposed between the base and the support;
A disc spring device wherein at least one of a contact surface on a substrate side contacting the disc spring and a contact surface on a support side contacting the disc spring is coated with a dissimilar material layer. The disc spring device according to claim 1, wherein the different material layer is a resin layer containing a polyamideimide resin as a main component. The disc spring device according to claim 2, wherein a lubricating material is mixed in the resin layer. The disc spring device according to claim 1, wherein the different material layer is a film containing diamond-like carbon as a main component. A disc spring device wherein at least one of a corner of the disc spring contacting the contact surface on the base side and a corner portion of the disc spring contacting the contact surface on the support is chamfered or rounded. At least one of the two corners formed on both ends in the thickness direction of the inner diameter surface and the two corners formed on both ends in the thickness direction of the outer diameter surface is chamfered or rounded. Disc spring featured. 6. A coned disc spring comprising a plurality of coned disc springs, wherein at least one of the disc springs disposed at both ends thereof is the disc spring according to claim 5.

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