DE1248349B - Procedure for setting the temperature coefficient of the natural frequency of metallic mechanical oscillators as precisely as possible - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY iD GERMAN FLlV PATENT OFFICE

EDITORIAL

Ini.C:

DeutscheKL: 42n ». | / 00

Number File number:

Registration day; Design day:

1243349

V 23975 IX a / 42 p

April 23, 1963

August 24, 1967

The invention relates to a method for setting the TcmpenituikoefB · zicntcn of the natural frequency (ΓΚΛ of mechanical mechanical oscillators as precisely as possible to a small positive or negative value given at the Noll or emeu value

As is well known, electric vibrators are deoie to an increasing extent by mechanical oscillators. The use of mechanical transducers is therefore advantageous for every babble because a number of metallic works substances of the Tcmpcraturkocffiaeni of the natural frequency can be observed very sticky, so that such a mechanical oscillator in contrast to electrical Oscillating circles from a temperature change to its immediate surroundings our is little influenced.

Egg are z. B. mechanical Schwingclcmcntc aas meiallJscbcr alloy on Nickcl-Ehen-Baris with Morybdinznsatz known. After suitable processing, these alloys have a very small temperature coefficient of the natural frequency (2 "JQ with about 5 to 10 · 10 ^-0 Z ⁰ C with a temperature range of about -60 to + IA) ⁰ C.

In the previously used processes for the production of mechanical oscillators or resonators from suitable steel material Procedure for setting the as precisely as possible Temperature coefficient dec natural frequency of metallic mechaoJschea oscillators

Register

VACUUM MELT Company with limited liability, Hanau / M., Grüner Weg 37

Named as inventor: Lothar Jung, Hanau / M.

gg oscillation frequency and certain temp-

Depending on the temperature of the oscillation frequency, the temperature coefficient was brought closer to the desired value of the temperature coefficient by means of a corresponding gradual heat treatment. It was "ch but that by icrtignngstcchnischc measures of materials and ScfawingerbersleUung scattering of Wcrkstoffeiieoichafteo, _3S as such. B. could not be avoided with regard to the speed of sound and the Tenaperaturkociflkn.

According to the state of the art, the Sticoung the speed of sound due to the fact that z. B. when the frequency adjustment Schwtngelentente the fluctuations in the speed of sound through an individual corrector the length of the transducer body can be compensated.

On the other hand, variations in the temperature coefficient of the natural frequency of oscillators which were made of the same material, so far not be compensated.

According to an older proposal, when setting up oscillators, the setting of the temperature limit to a predetermined value is thereby achieved achieves that the anisotropy of the Tcmperaiur koefftoentcn is used in this process the course of the anisotropy of the temperature coefficient as a function of the angle to the rolling direction within a strip of wood is determined and the material for the swing egg emcot then under taken from the sheet metal strip at such an angle to the rolling direction that the desired value des TcmpcTBtuTkocffizictHcn is received.

However, this older method does not fail use for pre-fabricated mechanical vibrating elements, but only for belts and Sheet metal. But it is for waste disposal as a source of material not suitable. For the manufacture of oscillating bodies, however, the use of round metal is often recommended.

Foundations are made of an alloy as about 40% nickel, about 9% molybdenum, about 0.5% beryllium, about 0.7% manganese, about 0.4% silicon and the rest iron produced oscillations · gcrkörpcrn caused between Mantclfl ^ CHCO and Kcrnzoncn inhomogeneities by prepared from the cast ingots of the specified alloy via hot · UOD optionally cold working, a round bar, this at a Temperaair VOA about 1050 ⁰ C in Wasserstoffatmosphärc for homogenization annealed, then cooled in air , then cold-faced and then tempered for about 30 minutes at about 600 to 700 ° C in a hydrogen atmosphere and the surface layer of the transducer body cut to the desired length is completely or partially removed or the core is drilled out so far until the temperature coefficient has increased or decreased to the desired value.

THfWOD

3 4

The invention can be traced back in more detail to the crystallographic structure of the structure with reference to the drawings

explained. permit. The outer surface of the with such in-

Fig. 1 shows the cross section of the oscillating element produced according to the invention,

appropriate vibrating element in the form of a round as already stated above, removed or

Staff. With d _a the initial outer diameter and 5 the core of the rod is bored out axially parallel to the

with d _e denotes the final diameter, which changes according to the ratio of the inhomogeneities and thus

Removal of the coat layer results; the TK _{S of} the vibrating element within a

A b b. 2 shows in a general graphical display of the range in the desired way to vary,

position the dependence of the TK ₁ on the ratio- In the following examples, the invention

nis d _e : d _{a of} a round rod; Proper procedure for setting a pre-

A b b. 3 shows the longitudinal view of a round bar. benen TK _f illustrated in vibrating elements.

Mitl is the length of the rod, mitd _{fl is} the beginning

borrowed outside diameter and with d _e the final diameter related to the setting of a certain

knife after removal of the coat layer; TK _f also set the target frequency of the vibrating elements

A b b. 4 shows a graphic representation that can be turned off. The setting of the independence of TC ₁ on the ratio d _e : d _a of the rod of 8 mm treated in frequency by changing the transducer length is known in Example 1; because according to the equation, e.g. B. for gate diameter; sion oscillator:

Fig. 5 shows a graphic representation of the.

dependence of TK _f on the ratio d _e : d _a des im 20 / -] /,

Example 2 treated round rod of 6 mm diameter 2 / [' ρ
catch diameter;

A b b. 6 shows a graphical representation of the / the natural frequency / the oscillation length, the dependence of the TK _f on the ratio of the inner G, the shear modulus and ρ the density of the oscillator diameter di to the outer diameter d _{a of} the material is Natural frequency inversely treated in example 3, 9 mm thick and proportional to the transducer length,
a central hole provided round rod; The following examples 1 to 3 to-

A b b. 7 shows the cross section of the material used for the vibrating elements in example 3

treated round rod with the outer diameter consists of a hardenable nickel-iron-metal

knife d _a and with the inner diameter d _{ . 30 alloy with 40.5% nickel, 9.02% molybdenum, 0.5%

The general principle of the invention can be applied to beryllium, 0.7% manganese, 0.4% silicon, remainder

explain in a playful way using Figs. 1 and 2. In iron.

A b b. 1 is the cross-section of such an oscillating example 1

element shown in the form of a round rod. This ^

Round rod has an initial outer diameter 35 Let it be a flexural oscillator in the form of a round knife d _a , which in the course of a surface rod according to A b b. 3 with a TK _f <C · 10 ~ ⁷ / ° C removal to a final diameter d _e . and a target frequency of 10 kHz.
If one follows the TK _f of such a round rod with this was added the above alloy melted decreasing diameter, by interrupting the exhaust and out of the cast ingot via respective hot wearing the jacket surface periodically and 40 and cold deformation determines a round rod with 9 mm the value of TK _f, so you get z. B. made the diameter. The wire was in A b b for 1 hour. 2 dependence of the TK _f at 1050 ° C in a hydrogen atmosphere on the diameter ratio d _e : d _a glows in the form. This was followed by cooling in air and a curve passing through points α and b. carried out a cold deformation of 21%, so

According to A b b. 2 with 45 that a wire with a diameter of 8.0 mm was present. At

an outer diameter d _a a negative Tempe ^ a sample of the thus treated 8 mm

raturkoeffteienten, the point α of the curve in wire, the surface area was removed and

A b b. 2 corresponds. Determined by removing the coat- the TK _f . A b b. 4 shows the dependency

area is the amount of the negative temperature of the TK _f from the ratio d ₆ : d _a . The above coefficient relatively quickly smaller, around 50 named wire with ad _a - 8 mm possessed a

corresponding to a certain ratio d _e : d _a at point b in negative TK _f of about - 1 · 10 ~ ^e / ° C

A b b. 2 to go through zero. Another removal of point e in A b b. 4. By removing the

the outer surface of the vibrating element leaves the outer surface, the TK _{t was} more positive to am

Temperature coefficients become positive. The in and the material density ρ was determined to be 8.25 g / cm ³ . A b b. 2 curve shown can go in line with the 55 zero. This information shows that

The idea of the invention is also entirely in the area of the positive starting diameter of the wire of 8 mm

tive or negative temperature coefficients of the corresponding to the ratio ά _έ '.ά _α - 0.885

Natural frequency lie. to reduce a final diameter of 7.08 mm

The cause of the change in the TK _f is carried to the initially raised demands for removal of the casing surface or by drilling 60 of the setting of a TK _f <1 x 1O ~ ⁷ / to satisfy ⁰ C,

of the transducer body is likely to be in inhomogeneities for the flexural transducer was next to the

Schwingermaterial lie justified. It is therefore ^ _o

aspired to in the oscillating elements between upper- Y a, <. 1 lü / L.

Areas close to the surface and the axis still require a nominal frequency of 10 kHz in terms of their size. To the to introduce changing inhomogeneities or 65 fulfillment of this requirement was initially the

cause the dynamic modulus of elasticity to be 18,610 kg / mm ²

and / or based on the concentration differences between the Le and the material density ρ as 8.25 g / cm ³ ,

alloy grains and / or differences in the structure of these variables and the known relationships

between the modulus of elasticity, density, frequency and wire diameter was then the length of the Vibrating rod was determined to be 54.45 mm.

Example 2

A torsional oscillator is to be produced whose TKf is the amount to compensate for the opposite frequency change of the electromechanical transducers when the temperature changes

TKf = +1 x 10-5 / ⁰ C

should have. The desired setpoint frequency of this torsional oscillator may be 100 kHz.

A round wire with a diameter of 9.0 mm was produced from the alloy material indicated. As in Example 1, the wire was annealed for 1 hour at 1050 ° C. in a hydrogen atmosphere and then cooled in air. The wire was then drawn in two puffs to 6 mm in diameter, accordingly a cold deformation of about 55%, pulled down, then V2 hours at 700 ° C tempered in a hydrogen atmosphere and cooled in the furnace.

This 6 mm thick wire treated in this way had a TK _f of approximately +2.4 · 10 −8 ^β / ° C. corresponding to point / of Fig. 5. By removing the surface area, the TK _{f increased} as a function of the ratio d _e : d _a along the line in A b b. 5 curve drawn. From this curve it can be seen that the required TK _f +1 · IO ^5/0 C at a ratio of d _e: d _a = 0.815 occurs. This means that the starting diameter of the wire has to be reduced from 6 mm to 4.9 mm in order to obtain the required XT _r value.

For this next to the torsional oscillator TKf = + 1 · 10 ^-5 / ° C have a nominal frequency of 100 kHz was required. The speed of sound c in the round wire reduced to 4.9 mm was therefore determined to be 2.9424 km / s and the transducer length of 14.712 mm was calculated from the known relationship c = / · λ.

Example3

It is called a longitudinal oscillator with a 77 £ _r amount is less than 1 × 10 ^-7 / ° C and a target frequency of 5OkHz. For this purpose, a round wire with a diameter of 9 mm was produced from the above-mentioned alloy. The wire was annealed for 1 hour at 1100 ° C. in a hydrogen atmosphere and then cooled in air and tempered for 30 minutes at 600 ° C. in a hydrogen atmosphere. A so-treated 9 mm thick wire had a TK + _f of 3.2 x ΙΟ ^"6/0 C corresponding to point ο in Fig. 6. drilling expected in a sample according to A b b. 7 the core to an inner diameter d _t off, one can also determine a dependency of the TKf on the ratio d _t : d _a . For the 9 mm thick wire obtained in this way, the result is that the TK _f can be reduced by drilling in accordance with the curve ο to q in 6. At a ratio di Fig: d _a = 0.723, q corresponding point, would have such a wire 77 to £ _r value zero..

For the above example longitudinal oscillator <i was 1 × 10 ^-7 been demanded ° C, a nominal frequency of 50 kHz / next to a TK _f. In order to be able to determine the exact length of the vibrating rod, the speed of sound at 4.605 km / s was measured in the 9 mm thick round wire, which had received an axial bore of 6.5 mm according to the ratio di : d _a = 0.723 mm given above . From the known relationship c = jX , the transducer length was then calculated to be 46.05 mm. This transducer with a length of 46.05 mm, with an outer diameter d _a = 9 mm and an inner diameter d _t = 6.5 mm, had, as required, a natural frequency of 50 kHz and a TC <1 · 10 "V ⁰ C.

With regard to Example 3, it should be emphasized that bores in vibrating elements for changing the coupling of vibrating elements of a mechanical filter are known. However, to make such a bore 77 for varying the £ _r value of an oscillating element was not previously known.

The vibrating element described in Example 2 had a length of 14.712 mm and a diameter of 4.9 mm. In purely weight terms, it represents only a very small fraction of the usual melt weight use for this alloy composition. B. 100 kg fusible link therefore a variety of such elements could be produced, the respective 77 £ _r value, due to the inherent scatter of property values in any large-scale production, would only be within a certain tolerance range.

Due to the method according to the invention, vibrating elements can be produced in a simple manner despite differing values of the TC _{f of} the starting material which practically all have the same TC _f and can therefore be used to build high-quality vibrator or resonator arrangements.

Claims (3)

Patent claims: 1. A method for setting the temperature coefficient of the natural frequency (TKf) of mechanical metallic oscillators to the value zero or a predetermined small positive or negative value as precisely as possible, characterized in that in the alloy of about 40% nickel, about 9% molybdenum , about 0.5% beryllium, about 0.7% manganese, about 0.4% silicon and the remainder iron produced oscillating bodies between the shell surfaces and core zones are caused by producing a round bar from the cast ingot of the specified alloy via hot and optionally cold deformation, this annealed at a temperature of about 1050 ⁰ C in a hydrogen atmosphere for homogenization, then cooled in air, then optionally cold-formed and then tempered for about 30 minutes at about 600 to 700 ° C in a hydrogen atmosphere and that the outer surface layer of the transducer body cut to the desired length completely or partially so strongly deviated or the core is drilled out until the temperature coefficient has increased or decreased to the desired value. 2. The method according to claim 1, characterized in that with oscillating bodies with round the cross-section, the removal of the outer surface by turning, grinding, scraping or Etching takes place. 3. The method according to claims 1 and 2, characterized in that the oscillator body axis parallel is drilled out. Documents considered: German Auslegeschrift No. 1147 335; U.S. Patent Nos. 1,880,923, 1882,398, 482;
Communications technical reports (NTF), Vol. 19, Pp. 34 to 37. For this purpose 2 sheets of drawings