JP2008121903A - Heavy belleville spring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a load-diplacement characteristic with small hysteresis, in a heavy Belleville spring piled up in parallel. <P>SOLUTION: A plurality of belleville springs 10 are piled up in parallel. The surface roughness of the mating surface of each Belleville spring 10 is within a range not less than Rmax 1.0 and not more than 2.0. A different material pile is prepared between each Belleville spring 10. If the surface roughness in this range, a loss of a force of the Belleville spring 10 dependent on rubbing can be made small. Moreover, if a different material pile is prepared between each Belleville spring 10, the characteristic is not deteriorated by the activity of a long time, either. By this, the load-displacement with characteristic small hysteresis can be obtained for a long period of time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lap spring that is formed by stacking a plurality of disc springs in parallel, and more particularly to a technique for reducing the hysteresis of the lap spring.

  The disc spring 10 is a machine part formed into a disc shape, and a through hole 12 is formed at the center thereof as shown in FIG. The disc spring 10 may be used as a single plate, but normally a plurality of disc springs 10 are used as a stacked disc spring. As a method of overlapping the disc springs 10, as shown in FIG. 7, a parallel stacking method in which the disc springs 10 are stacked in the same direction, and a serial stacking method in which the disc springs 10 are stacked in the opposite direction as shown in FIG. There is. In the case of the parallel stacking method, a large load can be generated with a small stroke (displacement). On the other hand, in the case of the serial stacking method, a large stroke (displacement) can be generated with a small load. For this reason, a serial system or a parallel system, or a combination of a serial system and a parallel system is used in accordance with the application to be used. For example, in the example shown in FIG. 9, the stacking disc springs stacked by the parallel stacking method are further stacked in series.

  In the above lap spring, when a load is applied from the outside, each disc spring 10 is elastically deformed, and the size of the diameter of each disc spring 10 changes. For this reason, when a load is applied to the lap spring and the disc springs 10 are elastically deformed, the disc springs are rubbed with each other to generate hysteresis. In particular, in the case of a parallel lap type lap spring, the contact area between the belleville springs is large, so that there is a problem that the hysteresis is also increased.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a lap spring having a load-displacement characteristic with small hysteresis in a lap spring of a parallel lap type.

In order to solve the above problems, the invention according to claim 1 is a lap spring having a plurality of disc springs stacked in parallel, and the surface roughness of the contact surface of the disc spring is Rmax 0.5 or more and 5. It is within the range of 0 or less.
In this lap spring, since the surface roughness of the contact surface of the disc spring is in the range of Rmax 0.5 to 5.0, the force caused by the friction between the disc springs when the disc springs are elastically deformed. Loss can be kept small. Therefore, a load-displacement characteristic with small hysteresis can be obtained.

In the above-described stacked disc spring, it is preferable that a different material layer made of a material different from the material of the disc spring is disposed between the stacked disc springs.
According to such a configuration, since the disc springs (the same kind of metal) do not come into direct contact with each other, it is possible to prevent the occurrence of adhesive wear due to long-term use (long-term rubbing). In particular, when the surface roughness of the contact surface is small, adhesive wear tends to occur, and thus such a configuration is effective. As a method for arranging the different material layers, for example, surface treatment is applied to the surface of the disc spring, or a spacer formed separately from the disc spring is arranged.

  The dissimilar material layer is preferably a dissimilar metal layer applied to the surface of one of the disc springs that are superimposed. According to such a configuration, since the dissimilar metal layer and the disc spring are integrated, the handling thereof becomes easy. Here, as a method of providing the different metal layer on the surface of the disc spring, for example, various surface treatment techniques (for example, plating treatment) can be used.

The dissimilar material layer is preferably a resin layer applied to the surface of at least one of the disc springs that are superimposed. By using the different material layer as the resin layer, it is possible to reduce the frictional force generated between the contacting disc springs, and to obtain a load-displacement characteristic with smaller hysteresis. In addition, the resin-type dry film process can be used suitably for the process which provides the resin layer to the surface of a disk spring.
In addition, when a different material layer is a resin layer, you may make it provide a resin layer on both surfaces of the disk spring which contacts. In this case, the resin layers come into contact with each other. However, unlike the metal layer, adhesive wear or the like hardly occurs in the resin layer.

  Further, it is preferable that a lubricant is mixed in the dissimilar metal layer or the resin layer. According to such a configuration, the friction coefficient of the surface is further reduced, and the loss of force due to the friction between the disc springs can be further reduced.

When the dissimilar metal layer or resin layer is provided on the surface of the disc spring as described above, the disc spring provided with the dissimilar metal layer or resin layer on both sides and the dissimilar metal layer or resin layer are not provided. The disc springs may be alternately stacked. According to such a configuration, since one disc spring does not need to be provided with a dissimilar metal layer or resin layer, the number of disc springs that require treatment for applying the dissimilar metal layer or resin layer is reduced. can do.
Further, unlike the above method, a disc spring provided with a dissimilar metal layer or a resin layer only on one surface (front surface or back surface) may be overlapped. According to such a structure, since each disk spring which comprises a laminated disk spring can be made into the same disk spring, it is not necessary to pay attention when stacking a disk spring.
Furthermore, when a resin layer is provided on the surface of the disc spring, the disc springs provided with the resin layer on both sides may be overlapped. In this way, there is no need to provide a resin layer only on one side in order to provide a resin layer on both sides, and each disc spring constituting the lap disc spring can be made the same disc spring. Spring handling becomes easy.

Moreover, it is preferable that the hardness of the said different metal layer is made soft compared with the hardness of a disc spring. According to such a configuration, a soft disc spring (a disc spring provided with a dissimilar metal layer) and a hard disc spring (a disc spring provided with no dissimilar metal layer) come into contact with each other. Can prevent wear.
For example, it is preferable that the dissimilar metal layer has a hardness of 50 Hv or more with respect to the hardness of the disc spring. In such a configuration, the hardness of the contact surfaces that rub against each other is sufficiently different, so wear can be effectively prevented.
Further, the hardness of the dissimilar metal layer is preferably 200 to 400 Hv, and more preferably 240 to 300 Hv.

The laminated disc spring of the present invention is preferably manufactured as follows. The stacked disc spring of the present invention can be manufactured through the process shown in FIG. As shown in FIG. 1, first, the inner and outer diameters are cut out by pressing the steel sheet. Thereby, a ring-shaped steel plate is manufactured.
Next, the surface of the steel plate formed into a ring shape is polished to make the steel plate have a desired thickness. That is, the plate thickness of the steel plate is adjusted so that the spring constant (load-displacement characteristic) of the disc spring becomes a desired characteristic. For example, the thickness of the steel sheet is reduced by about 0.3 mm by polishing. By this polishing, the surface roughness of the steel sheet becomes about Rmax 6.5.
Next, the ring-shaped steel plate is plastically deformed to be formed into a dish shape, and then heat treatment is performed. Specifically, after quenching, temporary return is performed, and main return is performed in a state where deformation is restrained by a jig (press temper). In addition, each process from the shaping | molding to a plate shape and heat processing is performed by the procedure similar to the manufacturing method of the conventional disc spring.

When heat treatment is performed and the plate is formed into a dish shape, the contact surface (front surface, back surface) is then polished (for example, buffed or the like). The surface roughness of the contact surface is preferably set to Rmax 0.5 to 5.0 by this polishing treatment. This is to reduce the loss of force (hysteresis) due to the friction between the disc springs. Here, if Rmax is smaller than 0.5, it is not preferable because it takes too much time (such as time) for the polishing process, and if Rmax is larger 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).
At this time, the flatness of the contact surface is preferably about 0.1 or less. This is to reduce the hysteresis.

When the surface roughness is sufficiently reduced by the polishing treatment, the surface treatment is applied to the contact surface of the disc spring (in FIG. 5, both surfaces of the front surface 14 and the back surface 16, or one of the front surface 14 and the back surface 16). Applied. By this surface treatment, a different material layer different from the material of the disc spring is applied to the contact surface of the disc spring. By providing the dissimilar material layer, the disc springs (similar metals) do not come into direct contact with each other and rub against each other, so that adhesion wear and the like can be prevented.
For the above-mentioned surface treatment, for example, a liubrite treatment, a molybdenum disulfide treatment, and various plating treatments (for example, electroless Ni plating, electroless Ni—P composite plating, chromium plating, etc.) can be suitably used. It is preferable that a lubricant is mixed in the film provided by such surface treatment. As the lubricant to be mixed, various known lubricants can be used. For example, a fluororesin (PTFE) can be used. The particle diameter of the mixed lubricant is preferably smaller than 1 μm. Note that the mixing ratio of the lubricant can be appropriately determined according to the characteristics required for the disc spring (for example, when the hysteresis is desired to be reduced, the mixing ratio is increased in order to reduce the friction coefficient). .
In addition, it is preferable that the thickness of the film | membrane provided by the surface treatment mentioned above shall be about 10 micrometers (for example, 5-15 micrometers). The reason why the thickness of the film is about 10 μm is to maintain the effect of the film over a long period of time.
Moreover, it is preferable to make the hardness of the film softer than the hardness of the disc spring (usually 400 to 500 Hv). This is because when the film is softened, it is possible to prevent the film from being worn (the wear of the disc spring surface in contact with the film). The hardness of the film is preferably about 200 to 400 Hv, more preferably 240 to 300 Hv. This is because when the hardness of the film is higher than 400 Hv, the effect of preventing the wear of the film is reduced, and when the hardness of the film is lower than 200 Hv, the strength of the film becomes insufficient.

Moreover, the film treatment which applies a resin solution can also be used suitably for said surface treatment. As the resin solution to be applied, for example, a resin solution such as a polyamideimide resin can be used. Moreover, it is preferable to mix a lubricant (for example, the above-mentioned PTFE) in the resin solution.
A dry film treatment can be used as a method for applying the resin film. Dry film treatment is, for example, first removing oil and dust from the disk spring surface, then applying a resin solution mixed with a lubricant, then drying the applied solution, and finally heating the dried film It can carry out by processing (200-300 degreeC). As a coating method, spraying, spray tumbling, and brush coating can be used. The film thickness of the resin film applied by such treatment is preferably about 10 μm (for example, 5 to 25 μm).

When the above surface treatment is completed, creep or hot setting treatment (for example, 200 ° C. × several tens of minutes) is performed to prevent sagging, then the height of the disc spring is checked, and the production of the disc spring alone is completed. To do.
When the disc spring is manufactured as described above, next, a plurality of disc springs manufactured in this manner are overlapped and grease is applied to form a disc spring. At this time, it is preferable that the surface on which the film is not formed is in contact with the surface on which the film is formed by the surface treatment described above. That is, since the two surfaces that come into contact with each other are made of different materials [film and steel (disc spring material)], it is difficult for adhesive wear to occur, and the surface can be maintained with a low coefficient of friction over a long period of time.
As a method of overlapping and contacting the surface on which the film is formed and the surface on which the film is not formed, (1) a film is applied to one surface (front surface or back surface) of all the disc springs to be superimposed, and those plates Either a method of sequentially stacking the springs, or (2) a method of alternately stacking a disc spring having a coating on both sides and a disc spring having no coating on both sides can be employed. In the method (1), it is only necessary to superimpose the same disc springs. Therefore, it is not necessary to pay attention to the order of superposition as in the method (2), and handling at the time of combination becomes easy. In the method (2), unlike the method (1), the number of disc springs to be surface-treated can be reduced. In addition, the disc spring which does not perform surface treatment can be manufactured by implementing the process except the surface treatment process shown in FIG.

Next, a stacked disc spring according to an embodiment of the present invention will be described.
In this example, 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 overlapped to form an overlap disc spring. The surface roughness of the contact surface of each disc spring was Rmax 1.6. In addition, two of the five disc springs are subjected to electroless Ni-P composite (PTFE diffusion) plating (thickness 10 μm) on both sides, and the remaining three are not subjected to plating treatment. These five disc springs were alternately stacked.
Moreover, as a modification, instead of the electroless Ni-P composite plating, the one subjected to the liubrite treatment, the one subjected to the molybdenum disulfide treatment, and the one subjected to the electroless Ni-P composite plating on each side are superimposed. (All the contact surfaces were coated). Furthermore, as a modification, a resin-type dry film treatment was performed instead of the metal film treatment described above.
In this embodiment, the target value of hysteresis is set within 10% of the specified load range.

First of all, loading and unloading is performed on a ladle spring (no film formation by plating etc.) with the surface roughness of the contact surface changed by changing the polishing conditions, and the relationship between the surface roughness and the magnitude of hysteresis is investigated. It was. FIG. 2 is a diagram schematically showing the load-deflection characteristic of a layered disc spring with the contact surface buffed and the load-deflection property of the layered disc spring not buffed. FIG. This shows the magnitude of hysteresis when the surface roughness Rmax of the surface is changed to 0.5, 1.6, 5.0, and 6.5.
As is clear from FIG. 2, in the disc spring subjected to buffing, the load is smaller in the forward path (when loaded) than in the disc spring not subjected to buffing, and in the return path (when unloading). The load has increased. Therefore, it was found that when the surface roughness is reduced by buffing, a load-displacement characteristic with a small load difference (hysteresis) between the forward path and the return path can be obtained. Further, as is apparent from FIG. 3, when the surface roughness Rmax is 5.0 or less, the hysteresis is sufficiently small as about 3.0 kN, and when the surface roughness Rmax exceeds 5.0 and is 6.5 ( When buffing was not performed), the hysteresis increased to about 4.5 kN.

  Next, with respect to the laminated disc spring in which the surface roughness Rmax of the contact surface was set to 1.6 by buffing and various surface films were formed after buffing, the number of repetitions of loading and unloading, and the number of repetitions (0 times) Table 1 shows the relationship between the magnitudes of hysteresis measured at 500 times and 1000 times. As a comparative example, only buffing (surface roughness Rmax 1.6) was performed, and a surface film was not formed.

  As can be seen from Table 1, in the case where the surface film was not formed by buffing alone, the hysteresis increased with an increase in the number of repetitions. On the other hand, it was confirmed that the layered disc spring in which the surface film was formed after buffing was able to suppress the increase in hysteresis even when the number of repetitions was increased and maintain the surface properties (low friction coefficient). In addition, in the case where the surface subjected to electroless Ni-P composite plating and the surface subjected only to buffing are brought into contact with each other, the surface subjected to electroless Ni-P composite plating is brought into contact with each other. There was no significant difference in size.

Next, with respect to the lap disc spring in which two disc springs having electroless Ni-P composite plating on both sides and three disc springs (surface hardness 450 Hv) not plated are alternately stacked, FIG. 4 and FIG. 5 show the results of measuring the hysteresis by varying the hardness of the electroless Ni—P composite plating film applied to the surface. FIG. 4 shows the hysteresis before repeating the load-unloading, and FIG. 5 shows the hysteresis after repeating the load-unloading 1000 times.
As apparent from FIGS. 4 and 5, it was confirmed that the hysteresis after 1000 times was greatly increased in the case where the superposed surfaces had the same hardness. It was found that the increase in hysteresis is suppressed when the hardness of the surface of the disk spring subjected to the surface treatment is 300 Hv, 250 Hv, 240 Hv, or 200 Hv or less.

  Next, the number of times the load and unloading were repeated and the number of repetitions of each of the repeated countersunk springs in which the surface roughness Rmax of the contact surface was set to 1.6 by buffing and the surface film was formed by the resin-based dry film treatment after buffing. Table 2 shows the relationship between the magnitudes of hysteresis measured at the number of times (0, 500, 1000). For the resin-based dry film treatment, a dry film lubricant in which PTFE fine powder was uniformly dispersed in a polyamideimide resin solution was used. In addition, what formed the surface membrane | film | coat on both surfaces was used for each disc spring which comprises a laminated disc spring.

  As is apparent from Table 2, the hysteresis became substantially constant even when the number of repetitions increased, and the deterioration of the load characteristics due to the repeated load was kept low. Moreover, the hysteresis after 1000 repetitions was also suppressed to a low value of about 3.0 KN, and good load characteristics were obtained.

As mentioned above, although the several 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 changes of the specific examples illustrated above.
In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, 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.

The figure which shows in order the process for manufacturing suitably the laminated disk spring of this invention. The figure which shows typically the load-displacement characteristic of the stacking disc spring to which the buffing was given, and the stacking plate spring to which the buffing was not given. The figure which shows the relationship between the surface roughness and the magnitude | size of a hysteresis. The figure which shows the relationship between the hysteresis measured before repeating a load of load and unloading, and the hardness of the film | membrane of the surface provided to a laminated disk spring. The figure which shows the relationship between the hysteresis measured after repeating the load of load and unloading 1000 times, and the hardness of the film | membrane of the surface provided to a laminated disk spring. Sectional drawing which shows the structure of a disc spring. The figure which shows the example of the piled disk spring of a parallel pile system. The figure which shows the example of the stacking disk spring of a series system. The figure which shows the example of the laminated disk spring which combined the parallel system and the serial system.

Explanation of symbols

10: Belleville spring 12: Through hole 14: Surface (contact surface)
16: Back side (contact surface)

Claims (19)

  A stacked plate spring in which a plurality of disk springs are stacked in parallel, and the surface roughness of the contact surface of the disk spring is in the range of Rmax 0.5 to 5.0. Spring.   2. The stacked disc spring according to claim 1, wherein a different material layer made of a material different from the material of the disc spring is disposed between the stacked disc springs.   The lap disc spring according to claim 2, wherein the dissimilar material layer is a dissimilar metal layer applied to the surface of one of the belleville springs.   4. The lap spring according to claim 3, wherein a disc spring provided with a different metal layer on both sides and a disc spring provided with no different metal layer are alternately stacked.   The double disc spring according to claim 3 or 4, wherein the hardness of the dissimilar metal layer is softer than that of the disc spring.   The double disc spring according to claim 5, wherein the hardness of the dissimilar metal layer is 50 Hv or more soft with respect to the hardness of the disc spring.   The lap spring according to claim 5 or 6, wherein the hardness of the dissimilar metal layer is 200Hv or more and 400Hv or less.   The lap disc spring according to claim 2, wherein the dissimilar material layer is a resin layer provided on a surface of at least one disc spring of the lap disc springs.   A plurality of disk springs are stacked in parallel, and the hardness of the contact surface between the stacked disk springs is that the other disk spring is softened with respect to one disk spring. A layered disc spring.   The stacked disc spring according to claim 9, wherein the other disc spring has a hardness of 50 Hv or more with respect to the one disc spring.   The lap spring according to claim 9 or 10, wherein the hardness of the other disc spring is 200Hv or more and 400Hv or less.   A plurality of disc springs are stacked in parallel, and a heterogeneous material layer made of a material different from the material of the disc spring is disposed between the stacked disc springs. Stacked plate spring.   The lap disc spring according to claim 12, wherein the dissimilar material layer is a dissimilar metal layer applied to the surface of one of the disc springs that are superposed.   The stacked disc spring according to claim 13, wherein a lubricant is mixed in the dissimilar metal layer.   15. The lap spring according to claim 13 or 14, wherein a disc spring provided with a different metal layer on both sides and a disc spring not provided with a different metal layer are alternately stacked.   The stacked disc spring according to claim 12, wherein the different material layer is a spacer formed separately from the disc spring.   13. The lap disc spring according to claim 12, wherein the dissimilar material layer is a resin layer applied to a surface of at least one of the disc springs that are overlapped.   The lap spring according to claim 17, wherein the resin layer is a film mainly composed of polyamideimide resin.   The lap spring according to claim 17 or 18, wherein a lubricant is mixed in the resin layer.

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