JPH0735838B2 - Bowl-shaped anti-vibration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> A measuring instrument stand that requires the transmission of vibrations of equipment, piping, etc. to reduce noise in the building interior or to be free from external vibrations. The present invention relates to the structure of an anti-vibration device used for such purposes.

<Prior art and its problems> Regarding the noise in the building, solid noise from equipment installed in the building is a big problem. As a measure for preventing solid noise, there is a preventive measure for equipment piping, etc., and measures have been taken using the conventional rubber member for vibration isolation and antivibration hanger, but sufficient countermeasure effect has not been obtained, Therefore, it is desired to develop a high-performance and inexpensive viscoelastic body (hereinafter simply referred to as a vibration isolation member) device.

As the conventional vibration-proof means, the rubber member shown in FIGS. 17 to 19, the vibration-proof rubber mat shown in FIG. 20, the air spring shown in FIG. 21, the spring coil, etc. are known.

The anti-vibration rubber device shown in Figs. 17 to 19 is for anti-vibration by the deformation of the rubber of the material, and the one that corresponds to the appropriate frequency and load is used depending on the material, and the range of application is limited. There is a problem such as deterioration of the material. The rubber mat shown in FIG. 20 has the same problem.

The air spring shown in FIG. 21 needs to be supplied with compressed air, has many auxiliary equipment such as a tank, is expensive, and needs to be monitored during operation and use. The spring coil has problems such as limitation of an applicable range of frequency and resonance.

Further, Japanese Utility Model Laid-Open No. 59-49138 (FIG. 8) shows a concave elastic body 11 'having a small radius on the inner surface, which is used when the floating floor 3'provides a load on its top. Is the top
As shown in FIG. 23, reference numeral 15 indicates a shape in which the top portion is bent and buckled, and the outer peripheral edge 16 of the elastic body with respect to the surface contacting the floor 1'of the building jumps up from the floor. There is a problem that the air in the elastic body easily escapes and the function of the elastic body is lost. (Refer to FIGS. 22 to 25) FIG. 26 shows the frequency (Hz) and the vibration transmissibility when the load is sequentially changed to 1 to 4 Kg by the conventional anti-vibration rubber member. As shown in the figure, the resonance frequency moves as the load changes, and the vibration transfer characteristics are shown in a diagram that changes sequentially, which makes it difficult to cope with vibration isolation. As shown in FIG. 27, the vibration transmission characteristic of the vibration isolator of the present invention is a characteristic of almost one line with a narrow width even if the load changes, so the vibration isolation characteristic is improved over a wide range with respect to the load.

<Object of the Invention> An object of the present invention is to propose a structure of a vibration isolator having a simple structure and also having a function of an air spring, excluding the drawbacks of the conventional vibration isolator.

<Summary of Means> In short, the present invention is such that a substantially bowl-shaped main body is formed of a viscoelastic material, and a flange-shaped extending portion is provided at an end edge of the main body opening side to face an object of the flange-like extending portion. A ring-shaped projection is provided on the surface to be contacted with the object to make the inside of the main body almost airtight, and the thickness of the main body is reduced from the flange-shaped extending portion toward the top, and the contact area with the main body is reduced by the load. A bowl-shaped vibration damping device characterized in that a changing load plate member is placed in contact with the top of the main body.

<Vibration Isolation Mechanism> (a) Reason for changing the wall thickness of the rubber member of the main body: When performing an anti-vibration design, the ratio f _{1 of the} frequency f ₁ generated by the machine to the natural frequency f ₀ of the anti-vibration device The larger / f ₀ , the better the anti-vibration performance, so it is important to make f ₀ as small as possible.

Further, generally, when a machine is operated under various loads, a portion corresponding to a mass (m) (a load is hereinafter referred to as a mass) is changed, and a natural frequency is changed, so that there is a problem that vibration damping performance is deteriorated.

The natural frequency f ₀ of the vibration isolator is calculated by the following equation using the spring constant k and the mass m.

In the case of a linear spring, the natural frequency changes when the mass (load) m changes, but in the present invention, the position of the rubber member of the main body deforms due to the change of the load, that is, the rubber thickness at the deformed position changes, so the spring constant Is designed to change sequentially.
In this case, the thickness of the rubber of the main body is determined and designed so that the ratio of spring constant and load (k / m) is constant.

By doing so, even if the load or the load changes, the natural frequency f ₀ is kept constant, and the deterioration of the vibration damping performance can be prevented, which is a great advantage for the vibration damping rubber.

27 and 26 show the resonance characteristics of the vibration isolator according to the present invention and a general rubber member in comparison. As shown in FIG. 27, the vibration isolator and the rubber of the present invention have almost one line for display, and the natural frequency does not change even if the load changes. As shown in FIG. 26, it is clearly shown that the natural frequency of the conventional anti-vibration rubber member moves when the load is changed. The anti-vibration device according to the present invention has unprecedented properties, expands the optimum range of anti-vibration properties in design, and is useful for anti-vibration of industrial machines and the like.

Although the spring constant of the rubber member is conventionally determined only by the hardness of the rubber, the vibration isolator of the present invention allows the characteristics of the vibration isolator to be freely designed by combining the shape characteristics and the characteristics of the rubber. This is a vibration proof device with a new concept that was made possible.

(B) Method of Contact between Load Plate Member and Rubber Member of Main Body and Change in Contact Area In the vibration damping device of the present invention, the contact area and contact method between the load plate member and rubber member of the main body are changed to The restraint condition is applied to the shape change of the rubber member to control the spring constant of the vibration isolator.

When a frustoconical load plate is used in Fig. 29 (Fig. 3A)
And a "load-deflection" diagram for a flat load plate member (Fig. 2A).

From this figure, when a frustoconical load plate is used, the slope of the "load-deflection" curve rises rapidly when the rubber surface contacts the inner surface of the frustoconical load plate. That is, the spring constant increases and the hard rubber member is obtained. This characteristic is usually used with a small spring constant and a low natural frequency, but when a sudden shock load is applied temporarily, the spring constant increases and the shock is moderated and displacement is constrained. It acts and acts as a shock absorber. In the conventional vibration isolator, measures such as attaching a stopper device separately are taken in order to prevent damage to the equipment against such an impact load. In the vibration isolator of the present invention, such a cushioning characteristic is incorporated in one main rubber member.

Further, when the rubber member is deformed, the surface of the rubber member of the main body is deformed while coming into contact with the load plate, thereby constructing the characteristics of the vibration damping device with large internal damping. That is, the amount of vibration energy converted into heat energy inside the rubber increases. This characteristic improves the vibration isolation and vibration isolation characteristics, and particularly, results effective in reducing fixed noise are obtained.

FIG. 28 shows an example of theoretical analysis of "load-deflection" of a conventional compression type vibration-damping rubber having almost the same load resistance as the vibration-damping device of the present invention. This figure shows that the internal damping of this vibration isolator is larger than that of the conventional type. The large internal damping means that the larger the inner area of the loop of the “load-deflection” curve, the greater the internal damping. The measured values are shown in FIG.

An embodiment of the bowl-shaped vibration damping device of the present invention designed based on the above idea will be described below.

<Embodiment 1> FIG. 1 (A) is a drawing showing a vertical section of a vibration isolator of a first embodiment. The main body 1 of the bowl-shaped vibration isolator having a convex outer surface is made of a viscoelastic material such as rubber. The outer surface of the bowl-shaped body should be a curved surface such as a spherical surface, a parabola, an ellipsoidal surface, a hyperboloidal surface, or the like.

The wall thickness t of the main body 1 shows an example in which it gradually decreases from the bottom edge of the bowl-shaped opening toward the value portion. Further, the lower surface of the bottom edge is provided with a brim-shaped projecting portion 2 having an annular projection 14 to improve the close contact with the surface of the contacting object 3 and to make the inside of the main body airtight. It is designed to increase

A load plate member 4 is provided in contact with the top of the bowl-shaped main body 1, and a load rod 6 is fixedly connected to the boss 5 by screwing or the like. Vibration and load are transmitted to the main body 1 by the rod-shaped body 6, and vibration is performed by deformation thereof.

It should be noted that the contact area between the bowl-shaped thin top of the main body 1 and the lower surface of the load plate member sequentially changes depending on the load. The length of the cross section from the thick portion of the bottom edge to the contact point is changed. In other words, FIG. 1 (A)
The unit width of the peripheral edge is a cantilever having a unit width, and the loads received by the load plate member can be understood by accumulating the cantilever beams at the peripheral edges. Simply speaking, the upper half of the bowl-shaped body is a curved surface that contacts the load plate member when the load is relatively small, and the lower half is a portion that functions when the load is relatively large.

When the load applied to the load plate member is small, it is used at a small spring constant (for example, the upper half of the bowl) where the spring constant is small. Also, when the load on the load plate member becomes large, a large area is contacted with the upper part of the bowl, and the thick bowl part with a large spring constant (for example, the lower half of the bowl) supports the load.
It is made to have a constant spring constant / mass ratio. The contact area between the load plate and the anti-vibration rubber contributes to the vibration damping effect due to the contact friction loss. At the same time, the air in the chamber 7 is compressed and a function as an air spring is also added, and vibration is isolated by these two mechanisms.

Further, by changing the size and shape of the load plate member as shown in FIGS. 1 (A) to 4 (A), the load displacement curve (spring constant of the spring constant of FIG. 1 (B) to FIG. 4 (B) is changed. Corresponding to changes)
Can be changed. (FIGS. 2-4 (A) 2-4)
(B) will be described later. ) However, the rod-shaped body 6 is the load receiving member 3 such as a channel beam.
Since there is a space between the buffer hole 8 and the buffer hole 8, the air in and out of the chamber 7 moves in and out of the buffer hole 8 and moves differently from a simple air spring with a buffer force.

Load and displacement in the load direction when a simple static load is applied δ
The relationship with is shown in FIG.

In the case of FIG. 1, the outer diameter D ₁ of the load plate member 4 is smaller than the outer diameter D ₀ of the bottom edge of the main body 1 to limit the contact area with the main body 1.

The first embodiment shows a linear plus nonlinear load displacement diagram with a small spring constant.

<Embodiment 2> Embodiment 2 is shown in FIG. _{2, in} which the outer diameter D ₂ of the load plate member 4a is substantially equal to the bottom edge diameter D _{0 of the} main body 1a, and the load is from above the load plate member. The case where it is added is shown.

In this case, there is no air leakage in the chamber 7a due to the deformation of the main body 1.
FIG. 2B shows a load and a displacement curve of the load plate member.

Its characteristics are large spring constant and non-linear. When the vibration isolator receives a load, as shown in FIG. 24, the flange-like extension and the object 3 come into contact with each other at two points, that is, the edge 17 and the annular projection 14 on the inner surface of the vibration isolator body. Airtightness of the air in the main body chamber 7a is sufficiently enhanced to enhance the effect of the air spring.

<Embodiment 3> FIG. 3A shows Embodiment 3 in which the outer shape of the load plate member 4c is a plate having a truncated cone shape in its cross section.

The contact area with the outer surface of the bowl-shaped main body is rapidly increased at an early stage of displacement of the load plate member, and the curve of the load and the displacement has a rapid rise as shown in FIG. 3 (B). The characteristics are such that the spring constant is maximum and non-linear.

<Embodiment 4> As shown in FIG. 4 (A), the load plate member is an inverted truncated cone block 4d, and as shown in FIG. 4 (B), the characteristics are small spring constant and linear.

<Embodiment 5> FIG. 5 shows a fifth embodiment of the present invention, in which two of the vibration isolator of FIG. 2 have a common load plate member and their tops face each other. Of course, the load plate member 4c shown in FIG. 3 may be formed by making the top side carrier portions contact each other.

Further, the bottom surface (top surface in the drawing) of the truncated cone block 4d in FIG. 4 may be formed by being interconnected.

The anti-vibration function is a combination of two anti-vibration devices.
Further, by providing a hole (orifice) 13 for communicating the chambers 7e, 7e of the body rubber members 1e, 1e which are vertically opposed to each other at the center of the load plate, the damping characteristic by the orifice can be changed.

<Embodiment 6> In FIG. 6, a sleeve 9 is provided in the plate body of the object 3f in place of the buffer hole 8 in the case of FIG. 1 to buffer the gap between the rod-shaped body 6f and the back length (length) of the sleeve. It is possible to adjust part of the buffer function by adjusting the resistance of the air breathing from the chamber 7f at the time.

<Embodiment 7> FIG. 7 shows a case in which a suspending connection fitting 10 is provided and the suspending load has the function of two vibration damping devices. The vibration isolator can be arbitrarily selected and combined with any type of the embodiments of the present application.

<Embodiment 8> FIG. 8 shows the case where one vibration isolator is attached to the connecting fitting 10a for suspension.

<Embodiment 9> FIG. 9 shows a vibration isolator when two bowls 11a and 11b having different sizes are connected in two stages to form one bowl.

<Embodiment 10> FIG. 10 shows the case of the two-stage type shown in FIG. 9, in which the upper bowl 11d and the lower bowl 11c are provided with a first load plate member on the upper bowl and the first bowl is provided. Plate member provided between the body and the second bowl body
The sleeve 11f is provided on 11e, and the sleeve 11 is provided on the target object.
Air breathing in g can be adjusted in two steps.

<Effects of the Invention> There are two types of conventional vibration damping devices, one that is simply expected to lose the elastic energy of the rubber, that is, vibration energy due to compression deformation inside the rubber, and one that simply utilizes the elastic properties of air shown in the air spring. It was.

On the other hand, when using the anti-vibration device according to the present invention, the following effects are obtained.

(1) In the vibration isolator according to the present invention, the main body is shaped like a bowl, and its wall thickness is changed toward the top to change the spring constant and the rubber member due to a change in the contact area between the curved surface of the bowl and the load plate member. Corresponding to the mass, the change in natural frequency was reduced to improve the anti-vibration effect. It was possible to form a vibration-damping characteristic not found in conventional vibration-damping devices. Therefore, by using the combination of the bowl-shaped rubber member of the main body of the present invention and the load plate, a device using vibration damping rubber having desired and various vibration damping effects was obtained.

(2) By placing the vibration damping device of the present invention on a flat plate, the characteristics as an air spring can be easily obtained, and a pressure air source is unnecessary.

(3) Experimental measurement values of FIG. 15 showing the vibration damping effect of the vibration damping device of FIG. 8 according to the present invention and FIG. 14 showing the vibration damping effect of the commercially available vibration damping rubber suspension It can be seen that when the anti-vibration rubber of the present invention is used, the anti-vibration side diagram is gentle and almost horizontal, and the anti-vibration effect is great.

FIG. 16 shows the vibration reduction (dB) with respect to the vibration side frequency (Hz) in comparison between the example of the present application and the commercially available product, and the bowl type vibration damping device of the present invention is remarkably excellent at any frequency. You can see that

[Brief description of drawings]

FIG. 1 (A) is a longitudinal sectional view of a vibration isolator according to a first embodiment of the present invention, FIG. 1 (B) is its load and displacement curve, and FIG. 2 (A) is a vibration isolator of the second embodiment. 2B is a longitudinal sectional view of the device, FIG. 2B is a longitudinal sectional view of the vibration isolator of the third embodiment, and FIG. 3B is a load and displacement curve. FIG. 4 (A) is a vertical cross-sectional view of the vibration isolator of the fourth embodiment,
FIG. 4 (B) is its load, displacement curve, FIG. 5 is a vertical sectional view of the device of the fifth embodiment, FIG. 6 is a vertical sectional view of the vibration isolator of the sixth embodiment, and FIG. FIG. 8 is a vertical cross-sectional view of an apparatus including a connecting fitting for suspending using two sets of vibration damping devices, and FIG. 8 is a vertical cross-sectional view of a device including a connecting fitting for suspending using one set of vibration damping devices.
The figure shows a vertical cross-sectional view of a vibration isolator in which large and small bowl-shaped bodies are connected vertically to form a two-stage structure. Figure 10 is the tenth embodiment in which the load plate members are located at the upper and lower bowl body connection positions in Figure 9. Example, FIG. 11 is a vertical cross-sectional view of an example of a change in bowl wall thickness, FIG. 12 is a vertical cross-sectional view schematically showing an applied use example in which a plurality of vibration damping devices according to the present invention are used for a measuring device, Similarly, FIG. 13 is a vertical cross-sectional view schematically showing the use in a leg portion of a mechanical device, FIG. 14 is a diagram showing the vibration-proof effect of a commercially available two-stage vibration-proof suspension, and FIG. 15 is the present invention. A diagram showing the vibration-damping effect of the first-stage vibration-damping device, Fig. 16 shows the vibration-damping effect of the commercially available vibration-insulating rubber mat and the bowl-shaped vibration damping device of the present invention.
A diagram showing vibration attenuation dB in vertical axis with Hz as horizontal axis, Fig. 17 is a side view of a conventional rubber vibration isolator, and Fig. 18 is a partial vertical sectional view of a conventional shear type vibration isolator. , FIG. 19 is a partial vertical cross-sectional view of a conventional shear type vibration-proof rubber, FIG. 20 is a vertical cross-sectional view of a commercially available vibration-proof rubber mat, and FIG. 21 is a vertical cross-sectional view of an example of an air spring.
Figure is a vertical sectional view of a conventional rubber member with a concave curve, Figure 23 is a schematic vertical sectional view showing the state in which it is buckled under load,
FIG. 24 is a partial cross-sectional view showing that the vibration isolator of the present invention has a two-stage seal by providing an annular projection on the contact surface with the object to improve the sealing effect, and FIG. Fig. 26 is a partial cross-sectional view showing that the sealing effect is reduced due to the contact end face outer peripheral line jumping up when a load is applied to the anti-vibration rubber in Fig. 26. Fig. 26 is a resonance characteristic diagram of a commercially available anti-vibration rubber member. FIG. 27 is a resonance characteristic diagram of a bowl type vibration damping device according to the present invention, FIG. 28 is a diagram showing load and displacement hysteresis loops of various vibration damping devices, and FIG. 29 is a frustoconical load plate. It is a load-deflection diagram by a flat load plate. DESCRIPTION OF SYMBOLS 1 ... Main body, 2 ... Collar-shaped extension part, 3 ... Target object 4 ... Load plate member, 5 ... Boss, 6 ... Rod-shaped body 7 ... Chamber, 8 ... Buffer hole, 9 ... Sleeve 10, Connection metal fittings, 11a, 11b ... 2-step main body outer surface 12 ... Board, 13 ... Hole, 14 ... Annular projection 15 ... Head, 16 ... Outer peripheral edge

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisao Suzuki 2-12-26 Konan, Minato-ku, Tokyo Konan Park Building Tosho Engineering Co., Ltd. (56) Reference JP-A-55-149441 (JP, A) JP 60-99850 (JP, A) Actual opening 60-64334 (JP, U) Actual opening 57-49138 (JP, U) Actual opening 57-131650 (JP, U)

Claims (6)

[Claims] 1. A substantially bowl-shaped main body is formed of a viscoelastic material, and a flange-shaped extending portion is provided at an edge of the main body opening side, and an annular shape is formed on a surface of the flange-shaped extending portion facing an object. A load plate member in which a protrusion is provided to make contact with the object and the inside of the main body has a substantially airtight structure, the wall thickness of the main body is reduced from the flange-shaped extending portion toward the top, and the contact area with the main body is changed by a load. A bowl-shaped vibration damping device, characterized in that it is placed in contact with the top of the main body. 2. The bowl-shaped vibration damping device according to claim 1, wherein the load plate member is provided with a load rod-shaped body for connecting the inside of the main body with an object to be stretched. 3. The tops of the two main bodies are opposed to each other, a load plate member is inserted between the two main bodies, and a hole communicating with the chambers of the two main bodies is provided at the center of the load plate members. The bowl-shaped vibration damping device according to claim 1. 4. Two vibration-damping members each having a rod-shaped body for loading are positioned so that the load plate members are spaced apart from each other, and are connected to each other via connecting metal fittings each having a surface in contact with the end of each main body. Claim 1 which forms the anti-vibration device of Claim 1.
The bowl-shaped vibration damping device according to item 2 or item 3. 5. The bowl-shaped vibration damping device according to claim 1, wherein the load plate member is a member whose outer shape is frustoconical in cross section. 6. A rod-shaped body which connects two large and small bowl-shaped main bodies with their opening sides facing downward and is connected in two stages via load plate members and which is connected to the load plate members of the upper body is The bowl-shaped vibration damping device according to claim 1, wherein the load plate member of the main body is inserted.