JPS5947541A - Vibro-isolating supporting body - Google Patents

Abstract

PURPOSE:To improve a damping characteristic against low-frequency vibrations in particular, by housing a sponge body in the thickness specified in a diaphragm device partitioning the inside into a working chamber and a balanced chamber, while exposing the respective surfaces to each of these chambers aforesaid, in case of a vibro-isolating supporting body such as an engine mount and the like. CONSTITUTION:A supporting metal fitting 2 to be set to the engine side is solidly locked to a bottom metal fitting 6 via an elastic member 4 such as a conical, cylindrical rubber or the like, and a protecting cap 8 to be set to the car body side is locked to the lower end of the bottom metal fitting 6. A partition plate 10 is installed inside an engine mount like this, while a diaphragm 14 is set up at the lower side of the plate 10 whereby a working chamber 12 and a balanced chamber 16 are partitionarily made up, and a noncompressive fluid 18 is sealed up in each of these chambers 12 and 16. And, the partiton plate 10 is composed of each of rigid upper and lower plates 22, 24 and a sponge plate 38 to be housed in each of concave parts 32, 34 set up at the central opposite surface side of each of plates 22 and 24, while the respective surfaces of the sponge plate 38 are interconnected through to each of these chambers 12 and 16 via vent holes 40 and 42.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-vibration support, and particularly to an elastic support such as an engine mount, which has excellent anti-vibration properties in high and low frequency ranges.

Conventionally, vibration-proof rubber mounts (vibration-proof supports) such as automobile engine mounts and body mounts have been used with a structure in which they are interposed between two rubber blocks and a metal fitting. If rubber with a small dynamic spring constant is used to reduce vibration noise in the high frequency range, the loss coefficient of such rubber will be small, and therefore the damping coefficient will also be small, making it sufficient to meet the characteristics required of a vibration-proof rubber mount. It was not possible to satisfy the requirements. However, anti-vibration rubber mounts such as engine mounts have low dynamic spring characteristics to reduce vibration noise in the high frequency range (near 1'0014), as well as low dynamic spring characteristics in the low frequency range (near 151]z). This is because it is required to have high damping characteristics (large loss coefficient) to reduce vibrations.

On the other hand, in order to meet such demands, various types of elastic supports, so-called fluid-filled mounts, have been proposed that take full advantage of the elasticity of rubber and the resistance to fluid flow.
The elastic buffer support proposed in Publication No. 7-9340 has a conical elastic member provided between a support plate and a lower plate, and forms an operating chamber filled with a predetermined fluid within the elastic member. In addition, two stop plates are provided to completely partition the working chamber from an equilibrium chamber surrounded by a flexible bag formed outside the working chamber, and an orifice of a predetermined length is provided in the stop plates. and a movable plate clamped by the stop plate is provided so as to be movable by the pressure applied to the fluid in the working chamber, thereby exerting an effective vibration damping effect. be. That is, in general, in this type of fluid-filled mount, when high-frequency vibration is input, the fluid in the working chamber acts as a rigid body. Therefore, even if rubber with a low dynamic spring constant is used as the elastic member, the mount as a whole has a low dynamic spring constant. 9, it was difficult to couple an effective vibration reduction effect, but this can be effectively achieved by changing the working chamber internal volume (absorbing fluid pressure) due to the movement of the movable plate. Furthermore, when low-frequency vibrations are input, the free movement of the movable plate is prevented by the stop plate, and the fluid flows from the working chamber to the equilibrium chamber through the orifice. By increasing the loss coefficient of the mount as a whole through the effects of flow resistance, etc., it is possible to effectively exhibit damping characteristics against low-frequency vibrations.

In this way, the fluid-filled mount using a movable plate proposed in Japanese Patent Application Laid-Open No. 57-9340 is superior to the conventional fluid-filled mounts. The inventors' examination revealed that there are some problems that still need to be solved. In other words, a low-frequency mount consisting of a fluid-filled mount with a movable plate that is designed to exhibit a low dynamic spring constant when high-frequency vibrations are input, and a large loss coefficient when low-frequency vibrations are input. The vibration of the area is input 1. In some cases, it is desirable to obtain a large loss coefficient, and it has become clear that there are cases where the damping characteristics cannot be fully demonstrated. In addition, in a mount having such a structure, a predetermined movable plate is movably held between two stop plates that partition the working chamber and the equilibrium chamber while sealing these compartments, and a high-frequency vibration It is necessary to design and assemble according to the required characteristics so that the sound of pressure fluctuations in the working chamber can be absorbed when the input frequency is input, but it is not easy to design by taking into account all the required characteristics in each frequency range. Furthermore, it is extremely difficult to assemble the movable plate accurately in a minute gap, which makes its manufacture extremely difficult.

The present invention has been made in view of the above circumstances, and its main purpose is to exhibit low dynamic spring characteristics in a high frequency range in a vibration isolating support using a fluid medium. On the other hand, the objective is to exhibit excellent high damping characteristics even in the low frequency range, regardless of the input low frequency vibration. An object of the present invention is to enable a vibration-proof support to be easily designed and produced.

In order to achieve these objects, the present invention provides a partition 9 means having a fin of a thick cylindrical body made of a rubber elastic body to form a working chamber -tJW in the cylindrical body. , an equilibrium chamber is formed by an enclosure at least partially made of a flexible thin film on the outside of the partition 9 means, and m is connected to the equilibrium chamber.
In the vibration-proof support body, which communicates with the working chamber J through the orifice nlJ, and in which the working chamber and the equilibrium chamber are filled with a predetermined incompressible fluid, the partitioning means AIJ is provided with a predetermined thickness. In addition to housing and holding the sponge body,
At least some molecules t4' on one side of the sponge body
JRL is exposed to the working chamber so that a square of incompressible fluid within the working chamber is made to act on the sponge body.

Therefore, with the vibration-proof support having such a structure, the sponge body housed and held in the partition 9 means for partitioning the working chamber and the equilibrium chamber is applied to the incompressible fluid existing in the working chamber by the input of high-frequency imaging. By effectively absorbing pressure 17 through its good deformation action, the dynamic spring constant of the support as a whole can be maintained low when high-frequency vibrations are input, thereby making it possible to fully exhibit a good vibration-proofing effect. When low-frequency vibrations are applied manually, a large damping coefficient can be obtained due to the extreme nonlinear characteristics of the spring of the sponge body itself or its elastic restoring action, regardless of the type of low-frequency vibration input. Thus, the problem of not being able to achieve a damping effect when a specific low-frequency vibration is input has been completely resolved. Moreover, such excellent vibration isolation performance in the high frequency range and low frequency range can be achieved by simply housing and holding a sponge body of a predetermined thickness in the partition means, making it extremely easy to design and manufacture. As a result, the work of assembling the vibration isolating support is facilitated, which has the advantage of reducing manufacturing costs.

Hereinafter, in order to clarify the present invention more specifically, some embodiments of the present invention shown in the drawings will be described in detail.

First, in FIGS. 1 and 2 showing an example of an engine mount which is a partial embodiment of the present invention, reference numeral 2 denotes a support metal fitting as a support member, which is a conical cylindrical elastic member formed in a ring shape. A ring 9 is integrally provided on the head of one end of the rubber 4, which is a cylindrical body, and a bottom metal fitting 6 is integrally attached to the bottom of the other end of the rubber 4. In addition, these supporting metal fittings 2. The bottom metal fitting 6 is vulcanized and bonded at the same time as the rubber 4 is vulcanized and molded, so that it can be easily manufactured as an integral member. A protective camp 8 is caulked to the lower end of the cylindrical tree 5 of the bottom metal fitting 6, and the engine is attached to the vehicle body via the support metal fitting 2 and the protective cap 8. This results in him being kicked. Note that 8a is a through hole for allowing air to circulate inside and outside the protective cap 8.

1. Inside this engine mount, a partition 9 plate 10 is provided which is located in a direction perpendicular to the vibration input direction, and an operating chamber 12 is formed within the conical cylindrical rubber 4. There is. Furthermore, the space below the partition plate 10 is filled with a diaphragm I4 as a flexible thin film whose peripheral edge is held by the caulking of the bottom metal fitting 6 and the protective cap 8.
The club activities are divided by the partition plate 1.
An equilibrium chamber 16 with a variable volume is formed between the 7 and 1.

A body 18 is placed in the working chamber 12 and the equilibrium chamber 16.
is included. 2o is a caulking transmission ring, and the protective cap 80 (partition play) 10 engages with the engagement flS of the bottom sound IS metal fitting 6 and is fixed by the force caulking action of the protective cap 80. It is becoming more and more popular.

In this engine mount, a working chamber 12 is provided.
and the equilibrium chamber 16 are separated by a partition plate 1 (l is
As shown in FIG. 1, a rigid upper plate 22 and a lower plate 24 made of a material such as metal or plastic are separated, and by overlapping these plates, a predetermined length is formed along the mating surfaces of their peripheries. A circumferential groove or orifice 26 is formed, and as shown in FIG.
One end of the orifice 26 is provided with an opening 28 that passes through the upper plate 22 and opens toward the working chamber 12. An opening 30 is formed therethrough and opens to the equilibrium chamber 16 side. Further, circular recesses 32 and 34 are provided in opposing central portions of the upper plate 22 and the lower plate 24, respectively,
A circular pocket 36 is formed by overlapping these plates 22 and 24, and the pocket 36 is filled with a sponge plate 38 of a predetermined thickness made of closed cells without any gaps. Furthermore, a plurality of circular through holes 40,42 as shown in FIG. sponge board 3
8 are connected to the working chamber 12.8 through the through holes 40.42e. They are each configured to be able to come into contact with the incompressible fluid within the balance chamber 16.

Therefore, with the engine mount) K having such a configuration, the pressure applied to the incompressible fluid in the working chamber 12 at the time of input of high frequency vibration is reduced by the pocket portion 36 of the partition plate 10.
The fluid pressure acts on one surface of the sponge plate 38 held in the interior through the through hole 40, and the surface of the sponge plate 380 on which such fluid pressure acts is effectively absorbed by the ease of deformation of the sponge plate itself. As a result, the spring characteristics of the rubber 4 can be effectively utilized, thereby lowering the dynamic spring constant as a whole and effectively reducing vibration noise in the targeted high frequency range. It can be forced. On the other hand, when low-frequency vibrations are input, the sponge body 38
Due to its own elastic action, an effective flow of incompressible fluid is induced between the working chamber 12 and the equilibrium chamber 18 via the orifice 26, and energy loss is formed there due to flow resistance, etc. As a result, it is possible to obtain a large loss coefficient that is effective regardless of the type of low-frequency vibration that is input, and it has become possible to exhibit a high damping effect against various types of low-frequency vibration. .

Incidentally, such an effect can be easily understood by comparing the following facts, which are some of the experimental results obtained by the inventors of the present invention. In addition,
The various types of engine mounts used are as follows.

Type A: The height of the pocket portion 36 is 5 mm, and the pocket portion 36 is filled with sponge plates 38 of approximately the same height (this invention).

B type: Similar to A type, a movable plate with a thickness of 1 part is held by the upper plate 22 and lower plate 24 at the periphery, and the center part is loosened so that it can be moved in the vertical direction. (conventional example).

Type C with static electricity injected into the second working chamber 12 (comparative example).

D type: A sponge body is present in the working chamber 12 (comparative example).

1 bow type: one in which a partition plate having an orifice 26 is simply provided as a partition means (through holes 40, 42, sponge plate 38, etc. are not present) (comparative example).

The results obtained using these types of engine mounts are shown in Table 1 below. In addition, the static spring constant (
Ks) was 15 kg/yttyyt.

According to Table 1 above, the A type engine mount in which the sponge plate 38 according to the present invention is held on the partition plate 10 has a low dynamic spring constant a1j that is effective against vibrations in the high frequency range. Moreover, even in the case of vibrations in the low frequency range, it has a large loss coefficient (O) regardless of its J width, and exhibits an effective vibration damping effect in the high frequency range as well as the low frequency range. On the other hand, with the conventional B-type engine mount with a movable platen, the loss coefficient (O) may be small in the low frequency range, and depending on the type of input vibration, the loss coefficient (O) may be small. In addition, in the case of type C, which has air in the working chamber, it is difficult to increase the loss coefficient in the low frequency range, and it is also difficult to increase the loss coefficient in the low frequency range. The dynamic spring constant of the D-type engine mount placed in the working chamber is large in the high frequency range, which indicates that the vibration isolation characteristics are not good in the idle frequency range. The E-type mount, which uses a partition plate made of Something has been revealed.

As described above, the engine mount in which the sponge plate 38 is accommodated and held in the support brake 1-10 according to the present invention is as follows.
It not only has an excellent vibration damping effect against high frequency vibrations, but also exhibits excellent damping characteristics (because the loss coefficient can be greatly reduced) against various types of low frequency vibrations. However, its excellent damping effect in the low frequency range has not yet been fully elucidated, and therefore it is only a matter of speculation, but it is probably due to the large number of bubbles present in the sponge plate 38. Due to the compressibility of the plate or the elastic deformation recovery action of the sponge plate 38, there is a phase difference between the pressure fluctuation of the incompressible fluid based on the input of low frequency vibration and the deformation of the surface of the sponge plate 38 due to the pressure fluctuation. Since this does not occur, this is different from the fluid movement as in the conventional movable platen, and more effective fluid movement is caused through the orifice 20, and this causes energy loss. Therefore, the above B
It is thought that this type of mount realizes a larger loss coefficient than the mount 1- which uses a movable plate, and also has effective damping characteristics against various types of low frequency vibrations. ing.

Moreover, according to such a mounting structure, a sponge plate 38 of a predetermined thickness is simply accommodated and held in the partition sib plate 1 (HC), and the pressure applied to the incompressible fluid in the working chamber 12 is applied to one surface of the sponge plate 38. Since the plate 2 of the 1002 partition plates
Compared to the conventional engine mount that clamps the movable plate between 2.24 and 24, the design is much simpler and easier, and as a matter of course, the assembly is also much easier and the manufacturing process is also easier. It also has the advantage of being easy and significantly reducing manufacturing costs.

Further, in the upper structure, a through hole 40 is provided at the bottom of the recess 32 of the upper plate 22, and a through hole 42 is also provided at the bottom of the recess 34 of the lower plate 24. The sponge body 38 is easily deformed by the force acting from the chamber 12 side. Note that the holes 8 and 12 are provided at positions corresponding to the holes 40 of the upper plate 22, so that the above-described deformation of the sponge plate 38 can be carried out more effectively. It has become.

Another embodiment of the present invention is disclosed in FIGS. 3 and 4, and similar parts having similar functions to those of the previous embodiment are designated by the same reference numerals. The explanation will be omitted, and only the different points will be described. First, in this embodiment, the engine mount is attached to the engine side via the support fitting 2, and on the other hand, it is composed of two parts 6a and 6b on the vehicle body side. Some examples of the bottom metal fitting 6 can be attached via bolts 44 provided on the flange.

Therefore, unlike the previous example, the protective gap 8 does not have a bolt part, and merely has the function of protecting the diaphragm 14 disposed and attached inside.

Further, in such a mount, a partitioning means 46 for partitioning the working chamber 12 and the equilibrium chamber 16 is composed of a rigid portion 42 having a pot-shaped recess.
A sponge body 48 is housed and held in the +i11 wall portion. More specifically, as shown in FIG. 3, the cylindrical part of the upper part 52 is press-fitted and fixed into the pot-shaped lower part 50, so that the enclosure of the pot side wall part is closed. A plurality of pocket portions 36 are formed in the pocket portion 36, and each of the pocket portions 36 is filled with a sponge body 48 having a predetermined thickness. In addition, the sponge body 48
Upper member 52° and lower member 50 corresponding to each surface of
Through holes 40, 42 are provided in the same way as in the previous example, and the incompressible fluid 18. in the working chamber 12, respectively. It is adapted to be brought into contact with an incompressible fluid 18 within an equilibrium chamber 16. The upper member 52 constituting the partition 9 means 46 is provided with a communication hole 58 of a predetermined length extending in the circumferential direction, and the peripheral edge of the lower part assembly 50 is also provided with a communication hole 58 of a predetermined length extending in the circumferential direction. A long communication hole 58 is provided, and the second side member 5
2 and the lower member 50 are overlapped, the two communicating holes 56 and 58 are connected to form an orifice of a predetermined length. Note that the communication hole 56 provided in the second side member 52 operates.

In this way, even if the partition means is pot-shaped and the sponge body is housed and held on the side wall thereof, one surface of the sponge body 48 can be inserted into the non-compressible part of the working chamber 12 through the through hole 40. As long as the sponge body 48 is in contact with the fluid 18, the pressure applied to the fluid when high-frequency vibrations are input is effectively absorbed by the deformation of the sponge body 48, and when low-frequency vibrations are input, The loss coefficient is increased by the extreme nonlinear characteristics or elastic restoring characteristics of the spring of the sponge body 48, thereby making it possible to exhibit excellent damping performance.

In addition, in the two embodiments described in Section 2, two members are used as partition means to accommodate and hold a prescribed sponge body, but as shown in FIGS. 5 and 6, The partitioning means is simply constituted by one partitioning plate 60,
A recess 62 is provided on the surface of the partition plate 60 on the working chamber 12 side, and a predetermined sponge plate 64 is filled therein.
By press-fitting a retaining ring 66 along the inner peripheral surface of the recess 62, the filled sponge plate 64 is held so that it does not come off, so that the sponge plate 64 is accommodated and held in the partition υ plate 60. It is also possible to According to this configuration, it is possible to increase the contact surface of the sponge plate 64 with the incompressible fluid. In addition,
Reference numeral 68 denotes a circumferential groove for forming an orifice extending over a predetermined length along the end face of the partition plate 60, and the partition means shown in FIG. A single partition plate 741 similar to the one shown in Figure 6.
5 and 6, and a predetermined sponge plate 64 is housed and held therein, but the difference from the previous example is that the four parts 6 in which the sponge plate 64 is housed are
A plurality of through holes 76 are provided at the bottom of the sponge plate 64 so that the sponge plate 64 is easily deformed by pressure applied from the working chamber side of the sponge plate 64.

By the way, although the degree of implementation has been explained in the second specific example, in order to make the working chamber 12 and the equilibrium chamber 16 communicate with each other,
As the orifice provided in the partitioning means, various known forms may be adopted as appropriate, and the orifice may be formed by simply drilling a hole in a single plate-shaped member. A fluid flow path serving as an orifice may be formed by superimposing two parts from each other, and furthermore, such an orifice may be provided in the partition means or at the periphery of the partition means. A circumferential groove may be used to form an orifice between the groove and the wall surface of the member to which the partition means is attached. The diameter of the orifice is 3~
10 yun (in the case of a rectangle, the area is converted), and the ratio of the orifice length (L) to the diameter (D) is T.
, /J) A value of about -8 to 30 is generally adopted.

Further, as the sponge body accommodated and held in the partition means 75, various known sponge bodies may be used, such as evaporated rubber,
It is a sponge body (foam) made of urethane, PVC, or olefin, and is composed of closed cells. In addition, such a sponge body is generally preferably manufactured with an expansion ratio of 5 to 50 times and a specific gravity of 0.5 to 0.001.

Further, the surface area of the sponge body accommodated and held in the partition means and exposed to the working chamber side is about 10 to 80% of the surface area of the partition means, and at such an exposure ratio, a predetermined sponge body is generally There is no gap in the recess formed in the partitioning means, and in some cases, objects up to twice the height of the recess are held down by a suitable holding member or a part having a through hole or a grid, and are compressed and filled. It is now possible to The thickness of the sponge body is appropriately determined in order to absorb the fluid pressure applied by vibrations in the high frequency range, and is generally about several mm, usually within the range of 3 to 10 gm.

It should be noted that the present invention is by no means limited to the above-mentioned examples, and may include the following without departing from the spirit thereof:
Various changes, modifications, etc. can be made based on the knowledge of those skilled in the art, and the present invention should be construed as including all such modifications, modifications, etc.

Moreover, although an example in which the present invention is applied to an engine mount has been described above, the present invention can also be applied to other anti-vibration supports such as the body mount 1-.

[Brief explanation of drawings]

FIG. 1 shows an engine mount 1 according to the vibration isolating support of the present invention.
Fig. 2 is a sectional view showing an example of - and Fig. 2 is a plan view of a partition plate serving as the partitioning means. Figure 3 shows
FIG. 4 is a sectional view showing another example of an engine mount to which the present invention is applied, and FIG. 4 is a perspective view of the bolt-shaped fittings U/JD means used therein. Figure 5 shows
It is a sectional view showing another example of the partition means according to the present invention,
FIG. 6 is a perspective view thereof. FIG. 7 is a diagram corresponding to FIG. 5 showing still another embodiment of the partitioning means according to the present invention. 2: Support metal fitting 4: Rubber 6: Bottom metal fitting 8: Protective cap 8a: Through hole
lO = partition sibrate 12: working chamber
14: Diaphragm 16: Equilibrium chamber 18:
Incompressible fluid 22: Upper play 1-24: Lower play 1-26.54 Niorifice 28. ．． 30: Open [1
Part 36: Pocket part 38.64: Sponge board 40
．． 42.76: Through hole 46: Partition means 48: Sponge body 50: Lower part 52: Upper member 56.
58: Communication hole 60. 74: Partition plate 62: Recess 66: Stop ring 68: Circumferential groove

Claims (1)

[Scope of Claims] (1) A support part is integrally provided at one end of a thick cylindrical body made of a rubber elastic body, and a partition means having an orifice is provided at the other end to form a wall inside the cylindrical body. A working chamber is formed in the partition means, and an equilibrium chamber is formed outside the partition means, at least a portion of which is made of a flexible thin film, and the equilibrium chamber and the working chamber are communicated through the orifice. on the other hand,
In the vibration damping support in which a predetermined incompressible fluid is sealed in the working chamber and the equilibrium chamber, the partition 9 means accommodates and holds a sponge body of a predetermined thickness, and one surface of the sponge body is 01. A vibration-isolating support, characterized in that at least a portion thereof is exposed to the working chamber, so that the pressure of the incompressible fluid in the working chamber is applied to the sponge body. (2) A plurality of through holes are provided in a portion of the partition means in which the sponge body is accommodated and held, and at least a portion of the other surface of the sponge body is brought into equilibrium through the through holes S. The vibration isolation support according to claim 1, which is capable of being brought into contact with a fluid on the chamber side. (3) The partition means is composed of a first partition member and a second partition member, and fills the pocket portion formed between the two partition members with the sponge body, and A plurality of through holes S are provided at least on the working chamber side of the first and second partitioning members where the sponge body is located, and the incompressible material is inserted into the sponge body through the through holes. The vibration isolation support according to claim 1, which is adapted to be brought into contact with a fluid. (4) The partition 9 means l! It has a recess that opens toward the working chamber, and at least (1) a wall portion of the recess is configured with a first partition part and a second partition part. 2. The vibration damping support according to claim 1, wherein the sponge body is disposed in the side wall sweat area. G5), the first partition 9 member and the second partition forming the pocket portion! l) f! Claim 3, wherein the plurality of through-holes are provided in the respective portions of the Ils, and the through-holes are arranged facing each other in the first partition 9 member and the second partition member. The vibration-proof support according to item 4. (6) The orifice is formed over a predetermined length in the circumferential direction by overlapping two partition members constituting the partition means, and extends through one of the partitions to one end of the orifice. One end of the orifice is opened to the working chamber side, and the other end of the orifice is opened to the equilibrium chamber side by penetrating the other partition wall. Anti-vibration support described in Crab.