DE2042159C - Holder for a circular disc-shaped ceramic resonator - Google Patents

Description

by a pair of resilient end plates that are attached to the

inner surface of the split halves are arranged 55, each of the resilient end plates having a

The invention relates to a holder for a line which extends through a recess in

circular disk-shaped, swinging in the radial direction - one of the divided halves extends through projections,

the ceramic resonator with an outer housing that is located in the inner housing to support the

and an inner housing which is in the outer geometric center of the ceramic resonator

housing is inserted. with the ceramic resonator 60 extending inward, through tongues that form the front

is provided in the inner housing and presses Hlek cracks of the end plates against the electrode,

has troden on both surfaces. and by a protective plate between a

U.S. Patent 2,817,778 discloses a shark pair of end plates in a space passing through the

tion for a disc-shaped, piezoelectric split halves is formed, is added

Crystal known, which has an outer housing and a 65 and a cylindrical recess for receiving the

inner housing includes. The crystal will have a ceramic resonator, at least the

over the circumference of the Rir.ge, which the i: m: re housing surface area of the protective plate made of an iso-

Hi! leu, held on, so that the possibility of im- lation material exists.

According to an advantageous development of the middle of the electrodes? ^^^^ n the invention, the cylindrical recess in the prints. be ^ "" ^ "^ MEnter, tarpaulin have a diameter which is slightly ^U £ ™ ^ J ^ g ™ ⁸ takes the same length Gosser than the outer diameter of the ceramic increased suspension. “ _{I think it's} too wide. resonators is. The protective plate can expediently 5 the strength of the ^ ug of _{the tongue} ^ provide at least three radial projections ^^^ X ^ jSe diameter of the keratin which protrude into the inner recess. slightly less aisoer a

the 'inner ends of the projections slightly from ^m * ^reS ° "^ ^S _G ' ^ ₁₁₅₆ has a pair of essentially

; _enl circumference of the ceramic resonator are removed. The "« ° eh J _{g and ff from}

_It is advantageous to look for a _good inorganic insulator or the top to be joined together

areas of the divided halves of the inner casing ^ ken ° rgani chen oderano ^ ^ _{3 t}

to be provided with connecting grooves and projections. from Met al ρ ^ « ^en 'J ^{e are} _coated on. the

^m ", the following are preferred e.nem ^ OnSMgMJ ^ f _{5a and} 5'α,

Embodiments of the invention on the basis of the two halves besrtze p ^ _{w £ nn dje H}

Drawing explained in more detail. ₁₅ .the jointly a space is fg. l ^g is a perspective_ «goded ^ view- ^ ΖΑ ^ Γοΐ" bSchricbcnenjKidcn_ end-

There, "lungs,.

elastic end plate which is used for the in F i g. 5 shown a ₅ ^s p ^{arations when} _{the two} halves joined together stabled embodiment is used; Sen grab these recesses and projections

d, e firmly on the opposite sides of the filter, ^ ^ rm _{inner housing smd more}

for example by fastening, are stacked. ^ J ^ f ^ _Aussp arungen Sd and Sd outgoing, det

The ceramic resonator 1 is in a zylmdrjschen 35 * f ™ S _nhemc £ these recesses is something

Opening 3a housed in a protective tarpaulin 3 De _ Hacn _{4a and 4} , _{fl> SQ that dl} e

from an isotator with a thickness that ger.ngfug.g fj ^^ recesses are added

arö-ier is designed as the thickness of the resonator, tongues vo

f _st The opening of the protective plate canoe any form ^k ~ _{outer Gehäuse6} made of metal or

exhibit. The protective plate 3 according to cüesem example e 4o Da. ^ UB ^ ^ ^ ^ _n S «te open D«

is with a number (preferably more than three), "dimensions of the housing", nd the receptacle

I inwardly projecting projection 3 'for receiving _d ^nne _"meng ^g _efügten halves 5 and J" W ^

of the resonator in a discontinuous cylinder _{- he jumps over} noses 7 and 7

? aunV, which is given by the inner ends of these projections Em pair ■ ^ ^^

S forms, provided. The diameter of the zyl.ndn- 45 of aeng κ _{this ße | spie} , _d

seta space is roughly larger than that of the resonator Djto ^ f _nFig . ₂ shown, st. Into the-

for example by 0.2 to 2.0 mm. The strong insulator, ™ £ J ⁿ f ^ ceramic resonator 1 in a cylindrical

Ju. The protective plate can consist of po y- b « ⁰ ^^^ _e : _nfiigt , _which by the .nne« n

oropylenharz, polycarbonate resin, Polyazctathara, neopentyl dri.cmen _ü y _{on the order} f _to g of the opening 3a

Sutschuk.Phenolformaldehyde resin, pressboard and 5 * ^ f ^ JSa is determined. The end plates 4

similar organic materials or inorganic materials of the Sdmggn. _{A rungBll} 5a and ^ S a ; the

Materials such as glass, mica (imcalex) and kera- and * ^w ^ _{h halves 5 and} 5 'with their supply lines

Sk, or from a metal core with a strong> ™ £ J ⁿ «%. _through the recesses SJ

icniQtor ührrzoeen is to exist. ⁶ , _, «,« »rprken accepted. uie auucicu

' ^S A "the gg? Nübe'rfc ₆ end Seiienι the Sch,". 55 »£ / '« ™ ^k | V «» <"""*« «?» "« * "

plaue 3 s, "d ™" endplates 4 and 4; PROCEDURES. ^ ", Chen de, recesses 5" uni15 "w. Made of a resilient material, we Phosphor- ™ _f 5 ~ _{c Ar} i _w i _r ddieSch _U Bpl» tte3, d, _e der, Keram.k-

SW the same Au.hau, u, - «-» «? £ -Ä" i & - ^

τ: isrrjisss.a- isj; · advises »t.rr„ _d sss ^ ä

i ",." one of its corners a supply line, 4,; »», ytalcteL »" ^^ "" ".,", in his.

turn ^BO df Um, »„ ₆ s _B , che der B „dp, _a „ e „4 1

clamped, and the leads 4c and 4'c of the end plates are held in the recesses Sb and 5'e by projections 5'b and 5e . The respective halves 5 and 5 'of the inner housing are held in the assembled state by means of additional connecting recesses and projections. The assembly is then slid into the outer housing 6 through its lower opening to complete the assembly. A casting resin such as epoxy resin can be poured into the bottom opening of the outer housing to form a water layer 8. The lugs 7 and T can be used to attach the assembly, e.g. B. on a circuit board can be used.

The construction described so far makes it possible to hold the ceramic resonator firmly by means of a sufficiently great pressure which is exerted by the end plates 4 and 4 'through the resilient tongues 4a and A'a. The protective plate 3, which is firmly attached inside the housing, prevents radial movements of the ceramic resonator 1 and protects it against damage from the outside. As a result, a displacement of the projections Ab and A'b from the geometric center of the ceramic resonator due to mechanical vibrations or impacts and the change in the resonance characteristics of the ceramic resonator due to the lateral displacement of the ceramic resonator 1 can be prevented. Even if the projections 46 and A'b are displaced from the geometric center of the ceramic resonator, the change in the resonance characteristic is relatively small, since the resonator is always supported by point contact with the projections.

example 1

On opposite sides of a ceramic disc with the composition

PbTiO ₆ - PbZrO ₃ - Pb (YNb) V ₂ O _:

and a diameter of 6.5 mm and a thickness of 1.5 mm, silver electrodes about 6 mm in diameter were attached by heating, so that a resonator having a resonance frequency of 350 kHz was formed. The resonator was inserted into the opening of an insulating plate made of polypropylene resin with the method shown in FIG. 1 brought the form shown. The protective plate had dimensions of 11 11-2 mm. The diameter of the cylindrical opening 3a was 9 mm and the diameter of the cylinder space formed by the inner ends of the projections 3b was 8.5 mm. The assembly of ceramic resonator, protective plate and end plates 4 and 4 'was placed in the inner case consisting of two halves made of propylene resin, and this assembly was inserted in an outer case 6 as shown in FIG. 1 is shown. This completed a ceramic filter that operates at 350 kHz.

The following are the vibration and shock tests to which this ceramic filter is subjected would.

Vibration test

The ceramic filter became a simple harmonic oscillation with an acceleration of Subjected to 10 g. The frequency of the oscillation was gradually increased from 10 Hz up to 55 Hz and then changed back to 10 Hz. This test did not change the resonance characteristics.

Shock test

The ceramic filter was dropped onto a concrete floor from a height of 1500 m. This test was repeated 10 times. It was found that the percentage change in the resonance frequency / r was ± 0.05 ° / ₀ and the mechanical quality factor ± 0.5 ° / ₀ ίο. These values are in the permissible range. F i g. 3 shows a modified protective plate 3 'with a continuous cylindrical bore 3'a, which has a diameter which is slightly larger than the outer diameter of the ceramic resonator. In another modified protective plate 3 "(Fig. 4), three radial projections 3 '" are formed on the circumference of the cylindrical opening 3 "a. The diameter of the discontinuous cylinder space defined by the inner ends of the projections ao parallel to the axis of the cylinder is slightly larger than the outer diameter of the ceramic resonator. The number of the protrusions 3 ″ is not limited to three.

Ils proved when using a ceramic filter for purposes that strong vibrations and impacts require, as advantageous, a relatively small number (e.g. 3) of the radial projections 3 '"in the Sfhi! T7nlaite according to Fig. 4 to choose and the diameter of the partial cylinder space formed by the inner ends of these projections by 0.2 mm larger than the outer diameter of the ceramic resonator. Then it is possible to use the Counter-effect on the vibration type of the ceramic modulator "; largely to reduce and the fluctuations in the mechanical quality factor and the Lower the resonance frequency to acceptable values.

F i g. 5 shows a modified ceramic filter arrangement in which, in addition to the ceramic resonator 1 and the electrodes 2, the parts that correspond to the parts in FIG. 1 and 2, are provided with a reference number increased by 10. The protective plate 13 corresponds to that in FIG. 3, and the end plates 14 and 14 'are in the shape of an L shown in FIG. 'Is shown, the main upper plate is provided with a projection 14' 6 for the end plate 14 provided h. The lower leg 14'r serves as a supply line. As in Fig. 7, one of the halves 15 and 15 'of the inner housing, ie half 15', has a recess with a shallow area 15'α and a deep area 15'6. The flat area 15'α receives the protective plate 13, the deep area 5'b the main plate of the end plate. You half 15 'is further provided with a recess verschen 15'1 that the vertical leg 14' c of the end plate receives. In this embodiment, the associated surfaces of the divided half 15 and 15 'are not provided with additional recesses and projections, as in the embodiment described above. Axial projections 14i and 14'Λ on the end plates are pressed against the gea metric center of the electrodes 2 and set! the stable operation of the ceramic filter.

Example 2

In the case of the in FIG. 5 shown embodiment has / .l the ceramic resonator a composition i - PbZrO ₃ -

and dimensions of 4 mm in diameter and 1.5 mm in thickness. Silver electrodes were made by heating applied to the opposite sides of the Kerarv.'kresonators, so that a resonator with a resonance frequency of 500 kHz. The protective plate was made of acetate resin and that inner casing made of mica (micalex). The cylindrical opening in the protective plate had an inside diameter of 4.2 mm.

The ceramic filter was ίο as with the previous one

written example, vibration and shock test. The following results were obtained.

Vibration test

There was no change in the filter characteristic 15 _{shape of} the protective plate.

between the outer diameter of the ceramic resonator and the cylindrical opening in the Plate was 0.2 mm, in the other case 2 mm. In this way six ceramic filters were made that worked at 350 kHz. These samples showed no change in their vibration characteristics. the The following table shows the results of impact tests that were carried out with these samples in the manner described above were carried out.

Shock test

Percentage change in the resonance frequency ± 0.06 ° / ₀ ; percentage change in the mechanical quality factor Qm ± 1.0 ° / ,.

It was also found that the change in the materials, the protective plate and the inner housing did not result in any noticeable change in the working properties. Three types of protective plates were produced, each having the same external and internal shape as shown in FIGS. _1, 3 and 4. Each type was produced in two types of rats, with one plate being the difference A Fig. 1

Fig. 4

0.2 mm
2 mm

0.2 mm
2 mm

0.2 mm
2 mm

Percentage change

for I Qm

± 0.03 ° / ₀
± 0.05 /,

± 0.05 ° / ₀
± 0.07 «/ ο

± 0.01 ° / ₀
± 0.03 /,

± 1.0 ° /, ± 1.5 ° / ₀

± 0.2 · /, ± 0.4 · / "

As it follows from this, that according to the invention < Ceramic filter has an improved holding mechanism, the mechanical shock and vibration egg without noticeable change in the work character stik resist and can be easily manufactured

1 sheet of drawings

309 6V

Claims (4)

favorable influencing of the oscillation ratio patent claims: the crystal exists. From the USA patent specification 3 17J 035 is a Ha! - 1. Holder for a circular disc-shaped, sion for a piezoelectric crystal known at Ceramic resonator 5 vibrating in the radial direction which the crystal in the circumferential direction by adhesive an outer case and an inner drop of cloth is attached. This type of housing, which is inserted into the outer housing, means that radial vibrations can also occur, the ceramic resonator being favorably influenced in the interior. Housing is provided and electrodes on both. U.S. Patent 3,299,301 describes a Has surfaces, thereby geke η η- ίο housing for receiving a circular disk-shaped draws that the inner housing of a ceramic filter, in which the ceramic filter on a Pair of hollow, split halves (5, 5 ') held from the essential side in the center by a spring. borrowed the same form exists, at least on the other hand, however, the depreciation takes place who carry an electrodeHe surface area on a larger area. of the divided half consists of an insulation material 15. Further solutions for holding a ceramic, as well as a pair of resilient end filters or piezoelectric crystals are made of plates (4, 4 '> which are on the inner surface of de ·. USA. Patents 2,824,219 , 2 624 854 and split halves (5.5 ') are arranged, whereby 3 221189, the British patents 456 390 each of the resilient end plates (4, 4') eii.e supply and 459 645 as well as the French patents line (4c , 4'c) , which is known from an Aus So 673 685 and 914 476. However, these known savings (S'b, 5'e) in one of the divided half constructions each have the disadvantage. (5.5 ' ) extends, through projections (4b, 4'b), which in no case a completely undisturbed Schwiusich in the inner housing (5 5) to support movement of the ceramic filter in the radial direction and in the geometric center of the ceramic is the same even with stronger ones Encounter reliable resonators (1) stretch inwards, support is ensured by tongues 25. In the case of radially oscillating (4a, 4'a), which press the projections (4b, 4'b) of the end ceramic filters, it is particularly advantageous to press the support plates (4, 4 ') against the electrode (2), points for the crescent-shaped Filter in a circle and through egg: ζ Protective plate (3) to be provided between the center point. The inclusion between a pair of end plates (4, M) in a space, springs in these points, however, is not sufficient. which is formed by the divided halves (5, 5 ') 30 because the filter will shift in the event of strong impacts, is received and can be cylindrical. Fixed in the center of the circle, ζ. Β Recess to accommodate the ceramic resonator soldered wires have the disadvantage that they have a denator (1), wöbe: at least the upper- neither hinder the oscillation or, ifr. They are kept thin in the very surface area of the protective plate (3) and are made of insulating material in the event of vibrations and impacts. _{35 can} break. 2. Holder according to claim 1, characterized in particular so far no ceramic filter is known, that the cylindrical recess has become resistant to strong vibrations and shocks the protective plate (3) can hold a diameter. has, which is slightly larger than the outer through- The invention is therefore based on the object knife of the ceramic resonator (1). 40 to create a holder for a ceramic filter, 3. Holder according to claim 1, characterized in that an undisturbed radial oscillation of a circle characterizes, that the protective plate (3) with a disk-shaped filter enables and at the same time Provided at least three radial projections (S ') ensures that in the event of strong vibrations and shocks that protrude into the inner recess, a displacement of the ceramic filter is excluded wobpj the inner ends of the projections (3) 45 remains. slightly from the scope of the ceramic reso- This task is erfindungsgenäli by a nators (1) are removed. Bracket for a ceramic filter solved that 4. Holder according to claim 1, characterized in that the inner housing consists of a indicates that the upper pair of hollow, split halves of substantially surfaces of the divided halves (5, 5 ') of the inner 50 of the same shape, with at least one Housing with connecting grooves and projections electrode-bearing surface area of the divided are provided. Half consists of an insulating material, as well as