JP2016223585A - Disc spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disc spring that can be greatly improved in durability while making good use of the advantage that a large load can be received in a narrow space (short height) that the disk spring has.SOLUTION: A disk spring 1 has a hole 10 formed in a center part, and comprises an annular inclined surface 11 which faces inward and an inclined surface 12 which faces outwardly. The inclined surface 11 which faces inward is formed into a convex curved surface and the inclined surface 12 which faces outward is formed into a concave curved surface in a cross section passing a center line L.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a disc spring.

  Belleville springs have a large degree of freedom in design, and can take advantage of being able to receive large loads in a small space (small height), so that clutches and brakes for construction machinery, tool chucks for machine tools, electrical machine breakers, It is used for various applications such as continuous casting equipment and bearing pressurizing parts.

  By the way, a disc spring that has been widely used conventionally is formed in a shape having a hole in the center and a circular truncated cone surface facing the inner side and a truncated cone surface facing the outer side (the center line of the disc spring) The cross-sectional shape when the disc spring is cut along the plane passing through is rectangular (or a rectangle having R surfaces at the corners of both ends or an oval having R surfaces at both ends), outside the frustoconical surface facing inward It was comprised so that a load might be supported by the periphery and the inner periphery of the frustoconical surface which faced the outer side (for example, refer patent documents 1-2).

JP 2013-167711 A Japanese Utility Model Publication No. 7-28246

  As described above, the conventional disc spring is configured to support the load with the outer peripheral edge of the truncated cone surface facing inward and the inner peripheral edge of the truncated cone surface facing outward. A large tensile stress is constantly generated at the outer peripheral edge and the inner peripheral edge of the frustoconical surface facing, and a large compressive stress is generated at the outer peripheral edge and the inner peripheral edge of the frustoconical surface facing outward.

  For this reason, the durability of the disc spring is mainly determined based on the magnitude of the tensile stress generated at the outer peripheral edge and the inner peripheral edge of the truncated cone surface facing inward.

By the way, in order to improve the durability of the disc spring, the following methods have been used alone or in combination.
(1) A method of dispersing the maximum stress generation location by forming a cross-sectional shape when the disc spring is cut along a plane passing through the center line of the disc spring into a rectangle or an oval shape having R surfaces at the corners of both ends. .
(2) A method of offsetting the tensile stress with the compressive residual stress by applying the compressive residual stress to the surface of the disc spring by shot peening.

  Although the above method has a certain effect to improve the durability of the disc spring, it requires labor for processing, increases the cost, and restricts the applicable disc spring. For example, the shape is small or deformed In the first place, the conventional disc spring has a large tensile stress on the outer peripheral edge and the inner peripheral edge of the frustoconical surface facing inward in the first place. Since a large compressive stress is constantly generated at the outer peripheral edge and the inner peripheral edge of the truncated cone surface, it has been difficult to dramatically improve the durability of the disc spring by the above method.

  In view of the problems of the above-described conventional disc springs, the present invention dramatically improves durability while taking advantage of the ability to receive a large load in a narrow space (small height) of the disc spring. It aims at providing the disc spring which can do.

  In order to achieve the above object, the disc spring of the present invention is a disc spring having a hole formed in the center, and having an annular inclined surface facing the inside and an inclined surface facing the outside. In the cross section through, the inclined surface facing inward is formed into a convex curved surface, and the inclined surface facing outward is formed into a concave curved surface.

  In this case, the convex curved surface constituting the inclined surface facing inward is constituted by an arc in contact with the ground contact surface when the unloaded disc spring is grounded with the inclined surface facing inward facing down. It can be done.

  Further, the concave curved surface constituting the inclined surface facing the outside can be constituted by an arc concentric with the convex curved surface constituting the inclined surface facing the inner side.

According to the disc spring of the present invention, in the cross section passing through the center line, the inclined surface facing inward is formed into a convex curved surface, and the inclined surface facing outward is formed into a concave curved surface, whereby the plate As the point supporting the load of the spring moves depending on the magnitude of the load, the stress distribution fluctuates, so that the outer peripheral edge of the frustoconical surface facing inward as in the case of conventional disc springs. In addition, a large tensile stress does not occur on the inner peripheral edge and a large compressive stress does not constantly occur on the outer peripheral edge and the inner peripheral edge of the frustoconical surface facing outward, and therefore, fatigue damage due to repeated load stress The receiving portions are dispersed, and the durability of the disc spring can be dramatically improved.
In addition, the disc spring of the present invention can take a larger load with respect to the deflection amount than the conventional disc spring, and further exhibits the advantage that the disc spring can receive a large load in a narrow space (small height). can do.

It is explanatory drawing which shows one Example of the disk spring of this invention. It is explanatory drawing of the fatigue test done using the disk spring of this invention. It is explanatory drawing which shows an example of the stress analysis result by the magnitude | size of the load of the disk spring of this invention. (A) It is explanatory drawing which shows an example which contrasted the disk spring of this invention, and (b) the conventional disk spring.

  Hereinafter, embodiments of a disc spring of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a disc spring according to the present invention.
This disc spring 1 has a hole 10 formed in the center, and a cross section passing through the center line L in the disc spring 1 comprising an annular inclined surface 11 facing the inner side and an inclined surface 12 facing the outer side, That is, in a cross section when the disc spring 1 is cut along a plane passing through the center line L of the disc spring 1, the inclined surface 11 facing inward is a convex curved surface, and the inclined surface 12 facing outward is a concave curved surface. , Each is formed.

  In this case, the convex curved surface that constitutes the inclined surface 11 is an arc that touches the ground surface when the disc spring 1 in an unloaded state is grounded with the inclined surface 11 facing inward (or to this). The radius R11 of the arc is set to about 0.5 to 1.2 times, preferably about 0.6 to 1.0 times the outer diameter D of the disc spring 1. It is preferable.

  Further, the concave curved surface constituting the inclined surface 12 is constituted by a concentric arc (or an arc close thereto) with the convex curved surface constituting the inclined surface 11 (thus, the thickness t of the disc spring 1 is The radius R12 of the arc is preferably set to 0.45 to 1.15 times, preferably about 0.55 to 0.95 times the outer diameter D of the disc spring 1. Is preferred.

  And this disc spring 1 is made to form the cross-sectional shape when the disc spring 1 is cut | disconnected in the surface which passes along the centerline L of the disc spring 1 in the ellipse which has R surface R13, R14 in both ends. .

Next, an example of the disc spring manufacturing method of the present invention is shown in Table 1 in comparison with a conventional disc spring manufacturing method.
Here, carbon steel (S65C) was used as the material of the disc spring.

  Here, setting is a process that applies a load exceeding the maximum value used in advance to the disc spring, causes a certain degree of permanent deformation, increases the elastic limit of the disc spring, and improves sag resistance and durability. Say.

  Next, Table 2 shows specification values of the disc spring of the present invention manufactured as described above.

  Here, the radius R11 and the radius R12 are affected by the spring back at the time of countersunk pressing, and the values on the outer and inner peripheral sides of the disc spring tend to increase. It is preferable to form in a shape.

  The disc spring manufacturing method and the disc spring material of the present invention are not limited to those described above. In the manufacturing method, for example, when mass production is performed, punching with a press used in a conventional disc spring is performed. It is possible to adopt a known method used for manufacturing a conventional disc spring, such as applying, various methods such as a lost wax method, a metal powder injection molding method, etc. In addition to carbon steel, known materials used for the production of conventional disc springs such as spring steel and alloy steel (for example, stainless steel) can be employed, and various metal materials such as titanium and tungsten can be employed.

  Next, the results of the fatigue test in which five disc springs according to the present invention are stacked as shown in FIG. 2 are shown in Table 3 in comparison with the results of the fatigue test using conventional disc springs. .

  The disc spring of the present invention did not break even when a repeated load of 2 million times was applied to the life of the conventional disc spring of about 500,000 times.

  Next, FIG. 3 shows an example of a stress analysis result (FEM (Finite Element Method) analysis result) according to the magnitude of the load of the disc spring of the present invention (when bending is advanced). 4 shows an example ((a) is a disc spring of the present invention, and (b) is a conventional disc spring) in comparison with those of a conventional disc spring.

As apparent from the stress analysis results shown in FIG. 3 and FIG. 4, the disc spring of the present invention has a cross section passing through the center line, and the inclined surface facing inward is a convex curved surface, and the inclined surface facing outward. , Each of which is formed into a concave curved surface, the stress distribution fluctuates as the location supporting the load of the disc spring moves according to the magnitude of the load, During use, a large tensile stress is constantly generated at the outer peripheral edge and the inner peripheral edge of the frustoconical surface facing inward, and a large compressive stress is generated at the outer peripheral edge and the inner peripheral edge of the frustoconical surface facing outward. For this reason, the part which receives the damage of the fatigue by repeated load stress is disperse | distributed, and it can improve the durability of a disc spring drastically.
Further, as shown in Table 3, the disc spring of the present invention can take a larger load with respect to the bending amount than a conventional disc spring, and receives a large load in a narrow space (small height) of the disc spring. The advantage that can be achieved can be further exhibited.

  As mentioned above, although the disc spring of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, The structure is suitably changed in the range which does not deviate from the meaning. It is something that can be done.

  The disc spring of the present invention can be used for various applications because it can drastically improve the durability while taking advantage of the fact that the disc spring can receive a large load in a narrow space (small height). It can be suitably used for a disc spring.

DESCRIPTION OF SYMBOLS 1 Disc spring 10 Hole 11 The inclined surface which faced the inner side 12 The inclined surface which faced the outer side L Centerline

Claims (3)

  In a disc spring comprising a hole formed in the center and having an annular inclined surface facing inward and an inclined surface facing outward, the inclined surface facing inward is convex in a cross section passing through the center line. A disc spring characterized in that a curved surface and an inclined surface facing outward are formed into a concave curved surface, respectively.   The convex curved surface forming the inclined surface facing inward is formed of an arc that is in contact with the ground contact surface when an unloaded disc spring is grounded with the inclined surface facing inward facing down. The disc spring according to claim 1.   3. A disc spring according to claim 2, wherein the concave curved surface constituting the inclined surface facing outward is formed by an arc concentric with the convex curved surface forming the inclined surface facing inward. .