RU74984U1 - ELECTRONIC VIBRATION PROTECTION DEVICE AND ELECTRONIC INSTRUMENT - Google Patents

Abstract

1. Vibration protection device of an electronic device having a housing and an electronic unit installed therein by means of a vibration protection device, wherein the vibration protection device is made in the form of at least three annularly curved segments of an elastic damping cable, each of which is fixed at its opposite ends on opposite sides of the electronic unit and, at least one point located between the ends is mounted on the housing, with at least two annularly curved segments of elastically damping t wasp lie in intersecting ploskostyah.2. The vibration-protective device according to claim 1, characterized in that it contains four annularly curved segments of an elastic damping cable spaced apart from adjacent segments by an angular distance of substantially equal to 90 °. Vibration protection device according to claim 1, characterized in that the ends of the segments of the elastic damping cable on each side of the electronic unit are fixed in close proximity to each other. Vibration protection device according to claim 3, characterized in that the ends of the segments of the elastic damping cable are fixed above and below the center of mass of the electronic unit, preferably at equal distances from the center of mass. The vibration-protective device according to claim 1, characterized in that the lengths of the segments, diameters, stiffness, elasticity and damping properties of the elastic-damping cable are selected so that the device has a minimum resonant frequency while maintaining the elasticity of the elements of the vibration-protecting device. The vibration-protective device according to claim 1, characterized in that the segments of the elastic damping cable are fixed on the housing at points that are located

Description

The technical field to which the utility model relates.

The utility model relates to the field of instrumentation and can be used to protect devices from vibration and shock.

State of the art

It is well known that any mechanical design can be conditionally represented as a system of masses, springs and dampers. Dampers absorb energy, but masses and springs do not. The mass suspended from the spring forms an oscillatory system, which has a resonance at its natural frequency characteristic of it. The natural frequency of an ideal mass-spring system without damping is determined by the ratio:

where Fn is the natural frequency; k is the spring coefficient of elasticity; m is the mass.

With increasing spring stiffness, the natural frequency also increases, and with increasing mass, the natural frequency decreases. Under actual operating conditions, mechanical influences, including vibration, are random in a wide frequency band. Thus, the vibration protection device must provide effective suppression of vibration in a certain frequency band, and the design of the device should not have resonant frequencies in this band. It is possible to derive the resonant frequency outside the range of operating frequencies either by increasing or decreasing its value. With increasing stiffness of the elastic elements, the resonant frequency of the vibration protection device increases, but at the same time, the efficiency of vibration reduction in the low-frequency region is significantly reduced. Thus, to ensure the effective operation of the vibration-protective device, its resonant frequency must be lower than the minimum value of the working frequency band. This requirement can be met by reducing the stiffness of the elastic elements of the vibration protection device.

On the other hand, if the system has damping, and this is true for all real physical systems, then the resonant frequency will be slightly lower than the value calculated by the above formula and will depend on the amount of damping. Thus, by using damping, a significant reduction in the resonance frequency can be achieved.

up to its removal beyond the working frequency band or into the low frequency range, in which some other type of vibration compensation can be applied, for example, electronic compensation.

A number of devices are known that use spring depreciation systems to absorb vibration effects. However, the use of such systems does not provide effective vibration suppression, since these structures have weak damping, that is, absorption of mechanical energy.

The use of a damper as a separate element in the vibration protection design significantly complicates the design and leads to an increase in overall dimensions. The need to use a damper in the form of a separate element is due to the fact that usually shock-absorbing materials have weak damping. However, it is possible to use the damping properties of the elastic cable based on the mutual friction of the cable fibers against each other. In addition, the cable also has elastic properties, which allows the cable to be used as an elastic-damping element. An analytical description of the physical properties of the cable is difficult, since it is a complex anisotropic structure. Therefore, the real mechanical properties of the cable vibration protection device is determined by the experimental data obtained during the testing of samples.

The use of cables as vibration damping elements in a vibration protection device makes it possible to obtain practically the smallest possible dimensions of a vibration protection device, provided that vibration is effectively suppressed. As an elastic-damping material, the cable has found application in various types of vibration protection devices, see, for example, publications FR 1372335 and FR 2624233. In these patents, the elastic-damping properties of the cable are used to suppress vibration during its bending operation. This method of using the cable provides ample opportunity to change the properties of vibration protection devices, for example, by increasing the radius of the loop into which the cable is bent, the elasticity of the loop decreases, which reduces the resonant frequency of the vibration protection device while maintaining operability, for which it is necessary to ensure that the cable loop does not sag due to increase the stiffness of the cable. The disadvantage of the proposed vibration protection devices is that they do not provide the identity of the mechanical properties of the suspension in different directions. In these devices there is a preferred installation option, regarding the action of the vibration vector.

The closest analogue of the claimed utility model is a vibration-proof device of an electronic device according to the document US 3204911. This device contains a support housing, a support unit (electronic unit) and several loops of elastic-damping cable, each loop connecting the attachment point of the support housing and the attachment point of the support unit. In one embodiment, the hinges are located on both sides of the supporting unit between the walls of the support housing, wherein the electronic unit is suspended above the support housing. On each side of the supporting block there are two cable loops oriented to each other in equilibrium at right angles. Such a device is very convenient for damping small vibrational loads in all directions, which is required for vibration protection of electronic devices, in particular, using crystal frequency stabilization devices, such as crystal oscillators.

A disadvantage of the known vibration-protective device is that for small cable loops, the resonant frequency of the vibration-protective device that is realized is high, which degrades the vibration-protective properties of such a device. On the other hand, with an increase in the size of the loops with the condition that its elastic properties are maintained to reduce the resonant frequency of the vibration protection device, the dimensions of this device are unacceptably increased. Thus, the disadvantage of the considered vibration protection device is the impossibility of ensuring its low resonant frequency while maintaining small overall dimensions.

Utility Model Disclosure

The objective of this utility model is to create a vibration-proof device of an electronic device that simultaneously has the following properties:

providing protection against vibration in all directions,

the resonant frequency is in the low frequency range,

minimized overall dimensions.

The vibration protection device of an electronic device having a housing and an electronic unit installed in it by means of a vibration protection device has the indicated properties, the vibration protection device being made in the form of at least three annularly curved segments of an elastic damping cable, each of which is fixed at its opposite ends on opposite sides of the electronic unit and at least one point located

between the ends, mounted on the housing, and at least two annularly curved segments of an elastic damping cable lie in intersecting planes.

The term “elastically damping cable segment” means a segment of a cable, rope, cable or other similar device consisting of several wires, threads, fibers, etc., as well as, possibly, a core and / or braid. As a rule, the cable is made of metal, but, if necessary, other structural materials with the necessary characteristics of strength and flexibility can be used.

The rings formed by the cable segments can have different orientations, however, in the preferred embodiment, the annularly curved cable segments are fixed in a manner equidistant at the points of attachment to the housing from adjacent cable segments.

In a preferred embodiment, the vibroprotection device comprises four annularly curved segments of an elastic damping cable, fixed in such a way that they are separated from adjacent segments by an angular distance of substantially equal to 90 degrees. In this case, the housing preferably has the shape of a rectangular parallelepiped.

The ends of the cable segments can be attached to the electronic unit in any suitable way, for example by gluing, welding, soldering, mechanical clamping, etc. In a preferred embodiment, to secure the ends of the cable segments on each side of the electronic unit, one fastening means is used, and with the indicated fastening means, all cable segments are fastened that fit on the side of the electronic unit on which the fastening means is mounted.

In one embodiment, the ends of the cable segments of the elastic-damping cable on each side of the electronic unit are fixed in close proximity to each other, which provides advantages when installing the cable segments, since in this case there is no need to fix the end of each cable separately, since the cable segments are in their end parts can be fixed in mounting devices, which are then attached to the electronic unit one at a time on opposite sides.

In a preferred embodiment, the ends of the cable segments of the elastic damping cable are fixed above and below the center of mass, preferably at equal distances from the center of mass of the electronic unit, since in this case a stable position of the electronic unit in a static position will be ensured.

The last condition can be met when fixing the ends of the cable segments not above and below the center of mass of the electronic unit, however, in order to ensure that the vibration-protective device has the specified properties and maintains its functionality, it is necessary to select the distribution of the lengths of the cables, diameters and stiffnesses of the cables and sizes loops formed by the ring-shaped segments of the cables, and places of fastening of the ends of the cable segments.

The resonance properties of the vibration protection device depend on many parameters of the components included in its composition. In a preferred embodiment, the lengths of the segments, diameters, stiffness, elasticity and damping properties of the elastic damping cable, as well as the size of the loops formed by the ring-shaped segments of the cables, are selected so that the device has a minimum resonant frequency while maintaining the elasticity of the elements of the vibration-protecting device.

The ring-shaped curved segments of the cables are fastened to the housing in the preferred embodiment at the points that are located in the middle sections of the cable segments.

Another objective of this utility model is the creation of an electronic device with improved vibration and mass-dimensional characteristics.

This problem is solved in an electronic device containing a housing and an electronic unit fixed in the housing by means of a vibration protection device, the vibration protection device is made in the form of at least three annularly curved segments of an elastic damping cable, each of which is fixed at its opposite ends on opposite sides of the electronic unit and, at least one point located between the ends is fixed to the housing. In this case, the housing in which the electronic unit is fixed by means of a vibration-protective device has the form of a substantially rectangular parallelepiped, preferably a cube. Other of the above embodiments of the vibration protection device can also be applied in an electronic device according to a utility model.

In one embodiment, the electronic unit included in the electronic device is further enclosed in an elastic shell, and in a preferred embodiment, the elastic shell has a spherical shape. The elastic shell is designed to protect against impact, as a result of which the electronic unit can collide with the housing of the device in which it is installed. The spherical shape of the elastic shell is preferred due to the fact that

in the case of shock, when the elastic shell contacts the device body, the contact area increases gradually, and shock energy is absorbed in any direction.

Brief Description of the Drawings

The drawings depict an example of the implementation of the vibration protection device and the electronic device with this device.

Figure 1 shows the vibration protection device of an electronic device.

Figure 2 shows a vibration protection device in which the electronic unit of the generator is enclosed in an elastic spherical shell.

Figure 3 shows a vibration-proof device mounted in the housing of an electronic device.

Figure 4 shows a graph of the degradation of the relative power density of the phase noise of a crystal oscillator without vibration protection.

Figure 5 shows a graph of the degradation of the relative power density of the phase noise of a crystal oscillator using the proposed vibration protection device.

In the graphs of the degradation of the relative power density of the phase noise of the crystal oscillator shown in Figs. 4 and 5, the lower curve shows the phase noise without vibration, and the upper curve shows vibration.

Utility Model Implementation

Figure 1 shows the vibration protection device according to the present utility model using an example of a quartz frequency generator. The ends of four annularly curved segments of cables 2 are attached to the electronic unit 1 of the quartz generator in the central parts of the bottom and the cover. Each of the segments of the cables 2 is attached at one center to the upper surface 3 of the electronic unit 1 of the crystal oscillator, and the other end to the center of the lower surface 4 Thus, the upper and lower ends of all segments of the cables are fixed on opposite sides of the electronic unit. The fastening of the cable segments is carried out in such a way that the rings formed by the cable segments 2 are placed in two mutually perpendicular planes. The ends of the cable segments 2 are mounted on the electronic unit by soldering.

In the embodiment shown in FIG. 3, the generator electronic unit 1 is further enclosed in an elastic protective sheath 5 having

spherical shape. In the case of impact, the elastic spherical shell 5 interacts with the walls 7 of the housing so that the contact area of the elastic spherical shell 5 and the wall 7 of the housing increases gradually, as a result of which the impact on the electronic unit 1 of the crystal oscillator is not short, but distributed over a certain period of time and less important due to the gradual quenching of impact energy.

Figure 3 shows that the electronic unit 1 in the spherical protective shell 5 with the annular segments of the cables 2 is attached by fixing the segments of the cables 2 in the middle parts of the rings formed by the cables (in this example, at points 6). Such fixation is carried out on the walls 7 of the housing in the form of a rectangular parallelepiped, preferably a cube, in which an electronic unit 1 of a crystal oscillator with a vibration-proof device is enclosed. When installing an electronic unit 1 of a quartz oscillator with a vibration-protective device in the housing, the vibration influences coming from the outside to the electronic device are perceived by the segments of the cable 2. Due to the elastic-damping properties of the cable, only a small part of the vibration effects are transmitted to the electronic unit, thereby significantly increasing the stability and accuracy of the electronic device for example a crystal oscillator. Due to the fact that the electronic unit is surrounded by annularly curved segments of an elastic damping cable, uniformly located around it on all sides, the electronic unit is protected from mechanical influences coming to the device from any spatial direction. At the same time, the compactness of the device is also provided, because the ring-shaped shape of the cable segments allows you to have minimal distances between the electronic unit and the device body.

The proposed anti-vibration device has the following properties. The resonant frequency of such a vibration protection device may have a relatively low resonant frequency value. When comparing the graphs of the degradation of the relative power density of the phase noise of the generator without vibration protection (Fig. 4) and using the proposed anti-vibration device (Fig. 5), it can be noted that the degradation of the power density of phase noise is observed only in the lower part of the range (up to 10 Hz). It follows that the resonant frequency of the vibration protection device has a value below 10 Hz.

The resonant frequencies of the vibration protection device, depending on the direction of action of the vibration vector, differ by 1-2 Hz, which is a fairly small value for the vibration protection device. Proximity resonance

frequency indicates that protection against vibration is carried out in all directions, and in all directions the vibration-proof properties of the device according to this utility model are the same.

This fact can be explained by the fact that the resonant frequency depends on the damped mass, the elasticity of the vibration protection device and the damping properties of the cables. Since the mass is constant, and the damping properties of the cables are the same, we can conclude that the elasticity of the vibration protection device is the same in all directions, which means that the vibration protection properties are the same. One of the additional properties of the vibration protection device according to the utility model is that it does not have a preferred orientation and position during operation due to the same vibration protection properties in all directions.

The proposed vibration protection device has minimal dimensions while maintaining operability, because to ensure the minimum resonant frequency of the vibration protection device, the rings formed by the cable segments should have the largest possible diameter while maintaining elasticity, and fixing the ends of the cable segments in the center of the electronic unit reduces the distance from the electronic unit to the point fastenings of the cable segment on the housing, required to accommodate the loop formed by the cable segment. When fastening the ends of the cable segments on the sides of the electronic unit, as far as possible from the attachment points of the cable segments on the case, additional stresses will appear in the design of the vibration protection device, for example, aimed at the turn of the electronic unit, which will degrade the vibration protection properties of the device according to this utility model.

Claims (10)

1. Vibration protection device of an electronic device having a housing and an electronic unit installed therein by means of a vibration protection device, wherein the vibration protection device is made in the form of at least three annularly curved segments of an elastic damping cable, each of which is fixed at its opposite ends on opposite sides of the electronic unit and, at least one point located between the ends is mounted on the housing, with at least two annularly curved segments of elastically damping t wasp lie in intersecting planes. 2. The vibration-protective device according to claim 1, characterized in that it contains four annularly curved segments of an elastic damping cable spaced apart from adjacent segments by an angular distance of substantially equal to 90 °. 3. The vibration-proof device according to claim 1, characterized in that the ends of the segments of the elastic damping cable on each side of the electronic unit are fixed in close proximity to each other. 4. Vibration protection device according to claim 3, characterized in that the ends of the segments of the elastic damping cable are fixed above and below the center of mass of the electronic unit, preferably at equal distances from the center of mass. 5. The vibration-protective device according to claim 1, characterized in that the lengths of the segments, diameters, stiffness, elasticity and damping properties of the elastic-damping cable are selected so that the device has a minimum resonant frequency while maintaining the elasticity of the elements of the vibration-protecting device. 6. The vibration-protective device according to claim 1, characterized in that the segments of the elastic damping cable are fixed to the housing at points that are located in the middle sections of the annular segments of the cables. 7. An electronic device comprising a housing and an electronic unit installed therein, characterized in that it comprises a vibration-proof device according to any one of claims 1 to 6. 8. The electronic device according to claim 7, characterized in that the housing has the shape of a substantially rectangular parallelepiped, preferably a cube. 9. The electronic device according to claim 7, characterized in that the electronic unit is enclosed in an elastic shell. 10. The electronic device according to claim 9, characterized in that the elastic shell has a spherical shape.