JPS6227292B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disc spring laminate in which a plurality of disc springs are stacked.

In general, as an elastic element made by combining a plurality of disc springs, that is, a disc spring laminate, there are known methods: a series method in which the disc springs are stacked one on top of the other, a parallel system in which the disc springs are stacked in the same direction, and a system in which series and parallel combinations are mixed. .

If the predetermined spring constant cannot be obtained using the above methods, the best way to obtain the predetermined spring constant is to change the design specifications of the disc spring, i.e., the outer diameter, inner diameter, thickness, deflection, etc. This is the usual conventional method.

The characteristics of disc springs are that, unlike coil springs, the stress caused by deformation is mainly tension and compression, and as metal springs, they have a much higher volumetric efficiency than coil springs, that is, the elastic storage energy within a certain space. , the spring constant can be freely set over a wide range depending on the combination method.

On the other hand, the disadvantages of a disc spring laminate that combines multiple disc springs are that a guide must be provided on either the inner or outer diameter, and if preload is required, the amount of deflection during preload cannot be taken sufficiently. That's true. Prestressing may be required, for example, when a disc spring laminate is used as a shock absorber for an elastic coupling. In elastic couplings, if an appropriate preload is not applied to the disc spring laminate, fluctuations in the transmitted torque will cause the disc spring to rattle and wear out.
It also generates noise. However, elastic elements are used in various machines and equipment because they can store a large amount of elastic energy in a small space and can sufficiently elastically follow the forced vibrations of a diesel engine with a frequency of about 10Hz to 3Hz. It is increasingly being used as

In equipment that requires the use of disc spring laminates to buffer shock loads or level out load fluctuations, there is generally no problem in applying a considerable amount of preload. many.

However, in some types of mechanical equipment, as with coil springs, only a very small proportion of the preload relative to the normal maximum load can be tolerated.

In such equipment, the disc spring laminate can only tolerate a very small amount of preload, for example about 0.5 to 1 mm. If the load is applied frequently, for example ¹⁰⁸ times a year, there may be some wear or deformation in the contact area of the disc spring.
That is, due to a decrease in the initial free height due to permanent deformation, the amount of preload is completely lost, and the product may become unusable.

As mentioned above, due to the requirements of the equipment, when it is used in a high load range during normal use, and only a very small amount of allowable preload is applied to the maximum load of the disc spring laminate, The load action range should be a combination of hard spring constants, and the low load range including preload loads should be an extremely soft spring constant, and a disc spring laminate with a non-linear spring constant that can provide a sufficient amount of preload. There is a need. One way to do this is to increase the number of layers of soft disc springs when using a soft spring constant in order to provide a sufficient amount of preload. becomes very large, and the mechanical equipment equipped with this disc spring laminate also naturally becomes very large.

This invention improves the above-mentioned drawbacks by providing a disc spring laminate with a small preload and a non-linear spring constant, which is extremely compact compared to the disc spring laminate with the above-mentioned normal combination configuration. Moreover, it is an object of the present invention to provide a disc spring laminate having a similar spring constant.

The disc spring laminate of the present invention is constructed by stacking in series a plurality of sets of disc springs in which at least one first disc spring and a second disc spring each having the same inner and outer diameters are stacked in parallel. ing. and,
The second disc spring has a smaller spring constant and a larger inclination angle of the spring plate surface than the first disc spring.

As described above, the disc spring laminate of the present invention combines disc springs having different spring constants. The necessary deflection during preloading can be obtained primarily by the second, soft disc spring with a small spring constant. That is, since the angle of inclination of the spring plate surface of the second Belleville spring is larger than that of the first Belleville spring, there is a gap between the spring plate surfaces of both Belleville springs stacked in parallel when no load is applied. Therefore, the second disc spring, which is soft, is significantly bent during preload.

As the load increases, the spring plate surfaces of the first Belleville spring and the second Belleville spring stacked in parallel to each other eventually come into close contact with each other, and the load is borne by both Belleville springs. Second
Since the deflection of the disc spring is limited by the first disc spring, excessive stress is not generated in the second disc spring.

Furthermore, since the first and second disc springs are stacked in parallel, the overall length of the disc spring stack can be shortened.

Next, an embodiment of the present invention will be described in comparison with a conventional disc spring laminate.

The manufacturing specifications for disc springs will be explained using DIN (German Industrial Standard) standard sizes.

Figure 1 shows outer diameter 100mmφ x inner diameter 51mmφ x thickness 6mm
×This is a disc spring laminate 1 in which 14 disc springs 2 with a deflection of 2.2 mm are combined in series. This spring characteristic is indicated by the symbol A in the load-deflection diagram in FIG. Now, if 516 kg is required as a preload load due to equipment requirements, the preload amount will be 2.54 mm, which is quantitatively insufficient for a long period of repeated fluctuating load.

If the conventional method is used to solve the problem, it is natural to install a softer disc spring in the height direction of the hard disc spring shown in Figure 1 to create a disc spring with specifications that will not damage the disc spring even if the disc spring is in close contact with the disc spring. However, according to this method, the free height of the disc spring laminate becomes large, which is disadvantageous in terms of space.At the same time, the spring constant of the disc spring laminate 1 shown in FIG. There will be a big change.

A disc spring laminate that can increase only the preload amount when the preload load is 516 kg without changing the overall space or spring constant will be described with reference to FIGS. 2 to 5.

Figure 2 shows outer diameter 100mmφ x inner diameter 51mmφ x thickness 5
This is a drawing in which 10 disc springs 4 with a diameter of 2.8 mm and a deflection of 2.8 mm are stacked in series, and the free height is 78 mm. The spring characteristics are indicated by reference numeral B in FIG. Figure 3 shows the outer diameter
This is a drawing in which 10 disc springs 6 of 100 mmφ x inner diameter 51 mmφ x 2.7 mm thickness x 3.6 mm deflection are stacked in series, and the free height is 63 mm. The spring characteristics are indicated by C in FIG.

The disc springs 4 and 6 shown in FIGS. 2 and 3 are
If you combine them one by one in the same direction (parallel) as shown in the figure, and configure 10 pieces in series, the free height will be
The height is 113mm, which is almost the same as the free height of 114.8mm in Figure 1.

In this case, the disc spring 4 shown by the spring characteristic B is in contact only on both the upper and lower surfaces of the inner diameter, and the deflection of each disc spring 6 shown by the spring property C is 0.8 mm, and the entire disc spring laminate is bent by 8 mm. As shown in FIG. 5, the disc springs 4 and 6 are in contact with each other at an inclined surface, and have a height of 105 mm. As shown in FIG. 6, the spring characteristics B+C of the disc spring laminate, which is a combination of the disc springs 4 and 6, are almost the same as the spring characteristics A in the normal usage range of 516 kg to 3000 kg.

Thus, according to the combination of FIG. 4 of the present invention, within the conventional space and with the conventional spring constant,
It is now possible to increase the preload amount by more than three times the conventional amount without changing the load conditions, which is very effective when it is necessary to set the preload load small.

The embodiment described above uses a DIN standard disc spring, but if the disc spring is specially designed, it is possible to apply a preload amount of six times or more.

An application example in which the present invention is highly effective will be explained.

FIG. 7 is a longitudinal cross-sectional view of an elastic coupling using a coil spring, and FIG. 8 is a cross-sectional view thereof. (Japanese Patent Publication No. 55-6777) In FIGS. 7 and 8, the elastic coupling has a first hub 12 and a second hub 16, the first hub 12 has a drive shaft 11, and the second hub 16 The driven shafts 15 are each fixed by a key or the like.

A disc-shaped protrusion 13 is provided in the radial direction at the end of the first hub 12, and the disc-shaped protrusion 13 is connected to the fixed flange part 22 of the shock absorber retainer 21 of the second hub 16 and the assembly. It is sandwiched between a removable flange 23 and a cylindrical annular portion 24, which are optionally separated.

A flange portion 17 is provided at the end of the second hub 16 in the radial direction. is integrally fastened to the reamer bolt 31.

The buffer body 34 includes a pair of spring seats 35 having a semi-cylindrical surface 37. The spring seat 35 is provided with two cylindrical protrusions 41 on a plane 38 on the opposite side of the semi-cylindrical surface 37 along the longitudinal center line. A pair of spring seats 35 and a coil spring 39 are constructed by inserting the protrusion 41 of the spring seats into the inside of the coil spring 39,
They are combined so that the coil spring 39 is sandwiched from both sides.

The buffer body 34 configured as described above is inserted into the buffer body holder 21. The center portion of the spring seat 35 is supported by an arcuate surface of an elongated hole 14 provided in the disc-shaped protrusion 13 of the first hub 12 . Further, both ends of the spring seat 35 are supported by spring seat receiving surfaces 26 and 27 provided by hollowing out the fixed flange portion 22 and the removable flange 23 of the second hub 16, respectively.

Torque is transmitted from the first hub 12 to the second hub 16 via the coil spring 39.

This elastic coupling is supported by semi-cylindrical spring seats at both ends of a coil spring, but since it is a coil spring, it usually does not require any preload.

The function of a coil spring is to temporarily accumulate energy through elastic displacement due to a reduction in free height, and to undergo elastic deformation in which the spring axis is curved. Performs axial center adjustment.

This coupling is effective enough for general drive systems, but if the load side is a crank press or the drive side is a diesel engine, variable torque will occur due to high frequency forced vibrations of 10Hz to 30Hz. Often. As couplings for such drive systems, elastic couplings for coil springs cannot absorb energy, so it is possible to level out fluctuating torque, and elastic couplings for metal springs require couplings that can absorb energy through friction. becomes. Therefore, it is extremely effective to use a disc spring laminate shown in FIG. 4 in place of the coil spring 39.

FIG. 9 uses a disc spring laminate 45 of the present invention,
A shock absorber is shown whose inner diameter is guided by a rectangular cross-section coil spring 46 and whose both ends are supported by a seat 49 having a semi-cylindrical surface 48. This buffer is the seventh
It is used as the buffer body 34 shown in FIGS. According to this, the coil spring 46 in the center can tolerate elastic deformation due to curvature of the spring shaft, and
There is also a damping effect due to the contact surface of the disc spring 45, making it ideal for applications where the above-mentioned forced vibrations are applied.

The shock absorbers of flexible shaft joints used for ships, etc. require a very small preload torque, so if the amount of preload is very small, their lifespan will be very short considering wear and fatigue. , there are major limitations from this aspect. In other words, periodic inspections are carried out every 2 to 4 years.
It requires a long life of 10 years, and the number of actions is 15 years.
Assuming continuous operation for one year at Hz, the frequency of action is 4.73 x 10 ⁸ times/year, and cannot be applied if there is not sufficient preload.

In the shock absorber shown in FIG. 9, which is an application of this invention, it is possible to reduce the preload amount, which was the single biggest drawback, and make it large enough without changing the conventional design specifications at all. , due to the friction between the contact surfaces of the weaker spring and the stronger spring, a greater damping effect than before can be expected.

Note that this invention is not limited to the above embodiments. For example, in a set of disc springs, two first disc springs and one second disc spring may be stacked in parallel. Furthermore, the spring constants of both the first and second disc springs may be changed by changing the materials of the first and second disc springs.

[Brief explanation of the drawing]

FIG. 1 shows a standard usage example of a disc spring, and FIGS. 2 and 3 are sectional views showing an example of a disc spring used in the present invention.
The figure is a cross-sectional view of a disc spring laminate of the present invention constructed from the disc springs shown in Figs. 2 and 3, and Fig. 5 is a sectional view of the disc spring laminate shown in Fig. 4 when preload is applied. , FIG. 6 is a spring characteristic diagram of the disc spring shown in FIGS. 2, 3, and 4, and FIG. 7 is a sectional view showing an example of an elastic coupling to which the disc spring laminate of the present invention is applied. 8 is a front view of the elastic coupling shown in FIG. 7, and FIG. 9 is a sectional view showing an example of a shock absorber using the disc spring laminate of the present invention. 1, 45... disc spring laminate, 2, 4, 6... disc spring.

Claims (1)

[Claims] 1. A first disc spring, and a second disc spring that has an inner diameter and an outer diameter that are approximately equal to those of the first disc spring, has a smaller spring constant, and has a larger inclination angle of the spring plate surface than the first disc spring. A disc spring laminate in which a plurality of sets of disc springs each stacked in parallel are stacked in series.