JPH07180738A - Ceramics elastic member - Google Patents

Abstract

PURPOSE:To provide the ceramics elastic member which is extremely small in the damping amount of a spring reaction, will never be ruptured and permanently set in fatigue even if it is subjected to high load at temperature in excess of 1000 deg.C and in a corrosive environment, enables its deflection to be set large as a large scale elastic member when the member is used as a shock absorbing member for various type equipment and a locking member for fastening sections, and can maintain a stable spring action for a long time. CONSTITUTION:This is a ring shaped-elastic member 2 bent in a wave shape, composed of a ceramic sintered body of a non-oxide whese corelation of (t) and D/N is in a range enclosed by the respective points of A, B, C and D as indicated in the figure where (t) represents thickness, D represents the average value of an inner diameter 3 and an outer diameter 4 and N represents the number of wave crests.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high temperature corrugated ring-shaped ceramic elastic member made of a non-oxide ceramic sintered body.

[0002]

2. Description of the Related Art Heretofore, elastic members made of various metal materials or synthetic resins utilizing a spring action have been widely used for buffering various devices or preventing loosening of their fastening parts.

In recent years, in the field of various industrial machines such as petrochemical plants, various high temperature heating furnaces, gas turbine parts, etc.
An elastic member that can withstand a high temperature of over 000 ° C and a corrosive environment of a gas or a medium is required, and a conventional elastic member has an extremely large attenuation rate of a spring reaction force during use at several 100 ° C. Since the spring action cannot be maintained due to so-called fatigue or corrosion, as an alternative to these, elasticity and flexibility are used as a material with low temperature dependence of spring constant and excellent corrosion resistance. Ceramic sintered bodies, which have been used only as rigid materials that do not have, have come to the forefront.

As the ceramic sintered body, a coil spring, a leaf spring or the like using a zirconium oxide sintered body, which has relatively high toughness among ceramics, has been put into practical use, but at a high temperature exceeding 1000 ° C. There has been a problem that the strength is severely deteriorated and, in addition, it easily reacts with metal such as pipes and nuts that come into contact with it, and it is difficult to stably maintain the spring action for a long period of time.

Therefore, by eliminating such a conventional defect,
There has been proposed a silicon nitride ceramic elastic member suitable for coil springs and the like, which has high strength at high temperatures exceeding 1000 ° C. and is sufficiently resistant to corrosive environments (see Japanese Patent Laid-Open No. 62-278168).

[0006]

However, the above-mentioned silicon nitride-based ceramics excellent in high-temperature strength and corrosion resistance are used as an elastic member composed of, for example, one coil wound at a high temperature exceeding 1000 ° C. When applied to spring washers, etc., ceramics generally have a higher elastic modulus than metals and are brittle materials, so if a large deflection is set, there is a high risk of breakage during use. There is a problem that since the damping ratio of the above is apt to vary, the reliability is poor, and therefore the bending must be reduced, and it can be used only for a very limited purpose.

[0007]

SUMMARY OF THE INVENTION The present invention has been made as a solution to the above problems, and its purpose is to buffer various equipment even under conditions of high load exceeding 1000 ° C. and high corrosive environment. It is an object of the present invention to provide a ceramic elastic member which can set a large flexure as a large elastic member as well as a small elastic member for preventing the fastening portions from loosening, and which maintains a stable spring action for a long period of time.

[0008]

In the ceramic elastic member of the present invention, the thickness of a plurality of corrugated ring-shaped elastic members made of a non-oxide ceramic sintered body is t (mm).
And the average value of the inner diameter and the outer diameter of the elastic member is D (m
m) and the number of wave peaks is N, the correlation between t and D / N is shown in FIG.
ABCD below, It is characterized by being within the range surrounded by each point of.

[0009]

According to the ceramic elastic member of the present invention, the material is a non-oxide ceramic sintered body, and the correlation between t and D / N is within the range surrounded by each point of ABCD shown in FIG. Therefore, the damping effect of the spring action, especially the reaction force is extremely small.
It does not break or settle in a short period of time even under a corrosive environment of high temperature exceeding 000 ° C.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The ceramic elastic member of the present invention will be described in detail below with reference to the drawings. FIG. 2 is a perspective view showing an embodiment in which the wave number N of waves of the ceramic elastic member according to the present invention is 3, and FIG. 3 shows another example of wave number N of waves of the ceramic elastic member according to the present invention being 3. It is a perspective view showing an example.

2 and 3, reference numeral 1 denotes a corrugated shape made of a non-oxide ceramic sintered body having a thickness t, an average value of the inner diameter 3 and the outer diameter 4 of D, and a wave crest number N of 3. It is a ceramic elastic member that is a bent ring-shaped elastic member 2, and has a mating port 5 in FIG. 3, and is the same ceramic elastic member 1 as in FIG.

The thickness t of the ceramic elastic member 1 is
If it is less than 0.34 mm, it breaks with extremely low stress, and if it exceeds 8.75 mm, the damping rate of the spring reaction force increases, so the value exceeds 0.34 mm and 8.75 mm.
The range is preferably 0.5 to 6.5 mm, more preferably 1.0 to 5.0 mm.

Further, the number of waves with respect to the average value D of the inner diameter 3 and the outer diameter 4, that is, the ratio of the number N of peaks of the peak counted from the peak of the adjacent peak as one wave is used for buffering or fastening. Not only to prevent loosening, but also considering the sealing property, it is necessary to hold the contact surfaces with the pipes and nuts in parallel, and if it cannot be held uniformly, the ceramic elastic member may break. The value of N is preferably 3 or more.

On the other hand, the average value D of the inner diameter 3 and the outer diameter 4 is 30
If it is less than mm, the flexure cannot be set to a large extent, so the application is limited and it is easily damaged by a low load.
If it exceeds mm, the distance between the peaks becomes large, and the inclination and sealability at the time of mounting become poor. Therefore, the average value D of the inner diameter 3 and the outer diameter 4 is in the range of 30 to 450 mm, preferably 50 to 50 mm. 360 mm, more preferably 60 to 300 mm, and as a result, the D / N value is specified to be 10 or more and 150 or less, preferably 20 to 120, further 30 to 10
0 is most preferred.

The non-oxide ceramic sintered body as a material of the ceramic elastic member is preferably sialon,
Although silicon nitride, silicon carbide and the like can be mentioned, other nitrides and carbides such as titanium nitride (TiN) and titanium carbide (TiC) can also be used.

Next, in evaluating the ceramic elastic member of the present invention, first, silicon nitride (Si ₃ N ₄ ) raw material powder is used as a sintering aid with alumina (Al ₂ O ₃ ) and yttria (Y ₂ O ₃ ). And rare earth element oxides such as ytteribia (Yb ₂ O ₃ ) are added, and a binder containing an organic solvent such as methanol and a known dispersant such as a surfactant is stored in a pot together with balls made of a silicon nitride sintered material. And then 1 on a rotating mill
A slurry was prepared by mixing and stirring for 2 hours.

The obtained slurry is granulated by a spray dry method into granules having a predetermined particle size, and the granules are granulated with 1.5.
A ring-shaped ceramic molded body having various wave crest numbers was molded by a press molding method at a molding pressure of t, and the molded body was molded into 5
The binder was removed at a temperature of 00 to 700 ° C.

Then, in a non-oxidizing atmosphere, 1600 to 18
Sintering was performed at a temperature of 00 ° C., and the obtained sintered body was subjected to finish processing to produce a ceramic elastic member which was a ring-shaped elastic member bent in a corrugated shape for evaluation.

As a method for forming a corrugated shape, a method of forming a molded body by a casting method or an injection molding method, or a method of machining a molded body, a calcined body, or a sintered body,
Various methods such as a method of heat molding can be adopted.

The thickness, the inner diameter and the outer diameter of the ceramic elastic member for evaluation thus obtained were measured at several points with a micrometer, and the average value D of the thickness t and the inner and outer diameter was calculated from the average value, and D / I asked for N.

Next, since only a minute change is recognized in an extremely long time in a normal use condition, when a load is applied to the ceramic elastic member for evaluation in the thickness direction thereof,
A strain gauge is attached to the surface portion corresponding to the wave pulling surface, and the ceramic elastic member for evaluation is attached to each ceramic elastic member in the creep tester at 100, 200, 300MP.
After applying and holding a load W in the thickness direction until the stress of a occurs, raise the temperature inside the creep tester to 1200 ° C, and carry out an acceleration test to measure the load w after holding for 80 hours in that state The change amount of the load with respect to the load W (W
The rate of change obtained by subtracting the ratio of -w) from 1 was evaluated as the damping rate of the spring reaction force.

Further, the Vickers hardness at 1000 ° C. of the ceramic elastic member for evaluation was measured.

Further, a length of 20 mm, a width of 20 mm, and a length of 10 which were manufactured with the same specifications as the ceramic elastic member for evaluation were used.
Using a 0 mm test piece, the longitudinal elastic modulus was determined by the bending resonance method, and the lateral elastic modulus was E / 2 (1 + ν) from the Poisson's ratio,
However, E was Young's modulus and ν was the lateral elastic modulus calculated using the Poisson's ratio formula.

The above results are shown in Tables 1 to 4, and the correlation between the number t of waves and the average value D of the thickness t and the inner and outer diameters is shown in FIG.
Shown in.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

As is clear from the results of Tables 1 to 4,
In the evaluation of the damping rate of the spring reaction force by the acceleration test, it is understood that the range surrounded by each point of EFGH shown in FIG. 1 is more preferable, and the range surrounded by each point of IJKL is the most desirable.

[0030]

According to the ceramic elastic member of the present invention, the thickness of a corrugated ring-shaped elastic member made of a non-oxide ceramic sintered body is t, and the average value of the inner and outer diameters of the elastic member. Is D, the number of waves is N, and the correlation between t and D / N is within the range surrounded by each point of ABCD shown in FIG. 1. Therefore, the damping rate of the spring action, especially the spring reaction force is extremely small. , 100
It does not break or settle in a short period of time under high temperature exceeding 0 ° C, or even in a corrosive environment, and it does not break, and it is used for buffering various equipment or preventing loosening of their fastening parts. For use, not only small size but also large size elastic member can be set to a large degree of bending, and a ceramic elastic member that maintains a stable spring action for a long period of time can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a correlation between the thickness t of a ceramic elastic member according to the present invention and the number N of wave peaks with respect to an average value D of inner and outer diameters.

FIG. 2 is a wave crest number N of the ceramic elastic member according to the present invention.
3 is a perspective view showing an example of FIG.

FIG. 3 is a wave crest number N of the ceramic elastic member according to the present invention.
FIG. 6 is a perspective view showing another embodiment of No. 3;

[Explanation of symbols]

 1 Ceramic elastic member 2 Ring-shaped elastic member bent in a wave shape 3 Inner diameter 4 Outer diameter

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // C04B 35/584

Claims (1)

[Claims] 1. A thickness of a corrugated ring-shaped elastic member made of a non-oxide ceramic sintered body is t, an average value of inner and outer diameters of the elastic member is D, and a number of waves is N. Time, t and D /
The correlation of N is the following ABCD in FIG. The ceramic elastic member is characterized by being within a range surrounded by each point.