JPH0128254B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a fluid-filled mount in which a weight is floatingly supported across a fluid chamber.
In particular, when the area of the weight is made as large as possible in order to further ensure the effect of blocking high-frequency vibrations, the weight should be kept horizontal in the fluid chamber like a piston and swing up and down smoothly, and the sliding of the weight should be The present invention relates to a fluid-filled mount that achieves a desired vibration isolation effect by minimizing dynamic resistance.

As shown in FIG. 9, a mounting member 220 connected to a vibration source such as an engine and a cylindrical body 211 of a base member 210 fixed to a fixed member such as a vehicle body frame are connected by an elastic member 230 made of a rubber material. A partition plate 215 formed on the inner circumference of the cylindrical body 211
A small circular hole 216 is provided in the center of the circular hole 21.
A small-area disk-shaped weight 250 is baked and supported by a ring-shaped elastic member 260 made of rubber material, and a diaphragm 2 is attached to the lower part of the cylindrical body 211.
40 is known.

An orifice 255 is formed in the center of the weight 250.

According to such a mount 201, the partition plate 215
The weight 250 floatingly supported in the circular hole 216 via the elastic member 260 resonates with the direction and phase of vibration reversed at the resonance point, so the vibrations are canceled out, but in the high frequency vibration region exceeding the resonance point, Weight 25
0 has a small area, the upper and lower fluid chambers 203, 2
Due to the low fluid movement capacity in 04 and the large area of the partition plate 215 that is integrated with the base member 210, micro vibrations are transmitted to the base member 210, as indicated by the broken line in FIG. As a characteristic, it was impossible to bring the dynamic magnification to high frequency vibration close to zero.

Therefore, the present applicant previously proposed in Japanese Patent Application No. 58-26076 a fluid-filled mount in which a large-area weight is floatingly supported across the fluid chamber, and the elastic member is removed from the mounting member in the high-frequency vibration region. and the fluid pressure generated in the fluid chamber due to the small vertical response of the large-area weight that follows changes in the relative position between the mounting member and the base member due to minute vibrations. They were roughly balanced and canceled each other out, making the dynamic magnification extremely low.

The present invention aims to further ensure the high-frequency vibration isolation effect in a fluid-filled mount in which such a large-area weight is floatingly supported across the fluid chamber. When the area of the weight is made as large as possible in order to achieve zero vibration, the weight is constructed so that it can oscillate up and down while keeping it horizontal, and the sliding resistance of the weight is made as small as possible to achieve the desired vibration isolation effect. The purpose of this invention is to provide a fluid-filled mount that can be effectively achieved.

In order to achieve the above object, the present invention has a weight that is supported by floating crosswise within the fluid chamber, and the area of the weight is larger than the effective area of the elastic member that determines the movement capacity of the fluid within the fluid chamber of the mount. It is composed of a large-area piston body, and a low-friction ring is fitted around the piston body, while a low-friction sleeve is fixed inside the cylindrical body that constitutes the peripheral wall of the fluid chamber, and the low-friction sleeve is inserted into the piston body through the low-friction ring and sleeve. The gist is that a piston body, which is a weight, is slidably fitted into a cylindrical body.

Preferred embodiments of the present invention will be described in detail below along with its basic principles with reference to the accompanying drawings.

First, to explain the basic principle of the present invention, FIG. 3 is a central longitudinal cross-sectional view showing the basic configuration of a mount in which a weight is floatingly supported transversely within a fluid chamber. The lower periphery of an umbrella-shaped elastic member 130 made of rubber material is baked onto the upper part of the cylindrical body 111 of the base member 110 forming the mounting piece 118 for the base member 110 . is baked into the upper center of the elastic member 130, and a disk-shaped attachment member 120 for connecting the vibration source is baked into the upper center of the elastic member 130.

An annular elastic member 160 made of a rubber material is provided on the inner periphery of the intermediate portion of the cylindrical body 111 of the base member 110 that constitutes the peripheral wall of the fluid chamber 102 of the mount 101.
The outer periphery of the annular elastic member 160 is baked, and the outer periphery of a large-area, thick disk-shaped weight 150 is baked on the inner periphery of the annular elastic member 160.

In this way, even the annular elastic member 160 can close the fluid chamber 1.
Since a large-area weight 150 is floatingly supported across the inside of the fluid chamber 102, the fluid chamber 102 is defined into an upper fluid chamber 103 and a lower diaphragm chamber 104.

In the illustration, the orifice 15 is located in the center of the weight 150.
5 is formed.

As described above, fluid (liquid in the drawing) is sealed in the fluid chamber 102 that is vertically defined by the weight 150.

Therefore, the fluid chamber 102 of the fluid-filled mount 101
Since the large-area weight 150 is floatingly supported across the inside, in the high-frequency vibration region, the mounting member 1 passes through the umbrella-like elastic member 130 that connects the base member 110 and the mounting member 120.
20 to the base member 110, and the fluid pressure generated in the fluid chamber 102 due to minute vertical movements of the weight 150 that follow changes in the relative position between the mounting member 120 and the base member 110 due to minute vibrations;
That is, in this case, the force transmitted to the base member due to the fluid pressure in the upper fluid chamber 103 is approximately balanced and cancels each other out. Therefore, the dynamic magnification can be extremely low, and high frequency vibrations can be blocked. The effect can be increased.

By the way, in order to further ensure the effect of blocking high-frequency vibrations, it is necessary to set the dynamic magnification of the fluid-filled mount 101 to approximately zero in the high-frequency vibration region.

Therefore, in this case, the force acting on the base member 110 from the mounting member 120 via the umbrella-like elastic member 130 is applied to the upper part by the weight 150, which moves up and down following the relative position change between the mounting member 120 and the base member 110. It is only necessary to ensure that the fluid is absorbed by the fluid moving up and down in the fluid chamber 103.

Therefore, a specific analysis will be described below.

First, as shown in FIG. 4, the effective area of the umbrella-shaped elastic member 130 that participates in the movement of fluid in the fluid chamber 102 of the mount 101 is S _E , and the fluid chamber 1
Weight 15 floatingly supported horizontally within 02
The weight 150 that participates in the movement of fluid due to the vertical movement of 0
The effective area of the inner circumferential portion of the annular elastic member 160 that supports this is defined as S _W , and S _W −S _E is defined as S _B. Here, the effective area of the elastic member is the area of the elastic member determined as the ability to contribute to fluid movement per unit relative displacement between the mounting member and the base member with the fluid chamber open to the atmosphere, and the effective area of the elastic member The area is the area of the weight determined as the ability to contribute to fluid movement per unit displacement of the weight with the fluid chamber open to the atmosphere.

Next, if we model the above mount 101,
As shown in FIG. 5, the effective area S _E of the umbrella-like elastic member 130 with a spring constant k that determines the fluid movement ability has a spring constant ak, and the peripheral portion that does not contribute to fluid movement. Of course, the area S _B has a spring constant K, and the effective area of the weight 150
The spring constant of the _SW part is dk. Here, both a and d are arbitrary constants.

The basic principle of the present invention is that the area of the peripheral edge of the umbrella-like elastic member 130 is increased by the fluid pressure P.
PS _B acting on the cylindrical body 111 of the base member 110 via the S _B portion and the force due to the spring component (spring constant k) of the elastic member 130 are balanced and cancel each other out.

This can be explained in detail as follows.

First, the paths of vibration transmitted from the mounting member to the base member are divided into the following two paths.

(b) A path transmitted through the elastic member (b) A path transmitted as pressure fluctuations of the fluid in the fluid chamber To further explain (b), first, when vibration is input to the mounting member, the vibration is transmitted between the mounting member and the base member. The relative position of the fluid chamber changes, which causes the pressure within the fluid chamber to fluctuate.

At this time, it is the effective area S _E of the elastic member that generates this pressure fluctuation, and the other surfaces of the fluid chamber are equally subjected to this pressure fluctuation.

However, among the remaining fluid chamber surfaces, pressure fluctuations acting on the effective area _SW of the weight are hardly transmitted to the base member side because the weight is supported in a floating manner.

In the above, since the effective area of the weight mentioned above is larger than the effective area of the elastic member, the pressure fluctuation acting on the portion S _B corresponding to the difference between the two effective areas causes a force in the opposite direction to the displacement direction of the mounting member. This force acts on the inner surface of the elastic member, so this force and the force (a) cancel each other out, making it possible to bring the overall vibration transmission as close to zero as possible.

Therefore, the area of the peripheral edge of the umbrella-like elastic member 130 must at least exceed zero, that is, be positive (S _B >0).

Here, since S _E + S _B = S _W , in order to make S _B > 0, S _W > S _E , that is, the effective area S _W of the weight 150.
It can be seen that must be larger than the effective area S _E of the umbrella-like elastic member 130.

However, the mounting member 120 and the base member 110
As shown in the figure, the elastic member 130 that connects the two elements has a complicated umbrella-like shape with shearing properties, so its effective area S _E cannot be determined by simple calculation.

Therefore, an actual test is performed to determine the effective area S _E of the elastic member 130.

First, in preparation for the test, the umbrella-shaped elastic member 130 is turned upside down as shown in FIG. 6, and its periphery is fixed. Then, the tube body 190 is attached to the lower flange 191 of the upper part of the elastic member 130, which forms an inverted umbrella shape. But hang it and fix it. Here, the upper part of the tube body 190 is open to the atmosphere.

After injecting a liquid, for example, water into the tube body 190 and letting it stand still, the inverse umbrella-shaped elastic member 13
The mounting member 120 integrated at the lower center of the
As shown in the figure, a forced displacement of lmm is applied from below. Due to this forced displacement, the liquid level rises inside the tube 190, and this increased volume Vmm ³ is actually measured.

Therefore, the effective area of the elastic member 130 is S _E =
It is obtained by V/l.

On the other hand, the same test as above is carried out for the weight 150, and its effective area _SW is obtained, and _SW > S _E is set as per the above-mentioned analysis results.

According to the fluid-filled mount 101 configured in this way and showing the basic principle of the present invention, the fluid chamber 1
02, the effective area _SW of the large weight 150 floatingly supported across the mounting member 120 is
and the base member 110.
Since the effective area of the elastic member 130 is larger than the effective area S _E , the area of the peripheral part of the elastic member 130 is
The force acting on the base member 110 via S _B and the force due to the spring component of the elastic member 130 are balanced,
They will cancel each other out.

Therefore, in other words, the force that is about to act on the base member 110 from the mounting member 120 via the elastic member 130 causes the weight 150 to move up and down in response to changes in the relative position between the mounting member 120 and the base member 110.
Therefore, the dynamic magnification of the mount 101 in the high frequency vibration region is set to 8.
As shown by the solid line in the figure, it can be made approximately zero,
As a result, the effect of blocking high frequency vibrations can be improved even more reliably.

By the way, if the area of the weight 150 is made as large as possible while satisfying the above conditions S _W > S _E and S _B > 0, the radial thickness of the annular elastic member 160 that supports it in a floating manner becomes thinner. Therefore, there is a possibility that the floating effect may not be performed smoothly.

Therefore, in the present invention, the weight is floatingly supported by an annular elastic member below or above, and the weight can be smoothly slid up and down with low frictional resistance like a piston inside the cylindrical body that constitutes the peripheral wall of the fluid chamber. did.

First, a first embodiment of a fluid-filled mount 1 according to the present invention will be described with reference to FIG. The lower outer periphery of an umbrella-shaped elastic member 30 having a hollow center portion is baked onto the inner periphery of the tapered portion 12 of the base member 10 forming the mounting piece 18, and a truncated inverted cone is formed on the upper inner periphery of the elastic member 30. The shaped mounting member 20 is baked.

The lower inner periphery of the tapered part 12 of the base member 10 is formed into an annular protrusion 13 having a smaller diameter than the inner diameter of the cylindrical body 11, and the mounting piece 18 is formed with mounting screw holes 19 for mounting on the fixed member. A mounting screw 21 for attaching to a vibration source is provided protruding from the upper center of the member 20.

On the other hand, the weight 50 is placed concentrically on the lower surface of a thick disk-shaped piston body 51 having an effective area S _W that is sufficiently larger than the effective area S _E of the umbrella-like elastic member 30 including the mounting member 20 . The piston body 51 has three annular fitting grooves 52, 53, and 54 on the outer periphery of the piston body 51.
A piston ring 71 is fitted into the intermediate fitting groove 53, and guide bushes 72, 73 are fitted into the upper and lower fitting grooves 52, 54, respectively.

The inner periphery of an annular elastic member 60 having a sufficiently large radial wall thickness is baked onto the outer periphery of the cylindrical portion 56 of the weight 50, and the outer periphery of the annular elastic member 60, which has a diameter slightly larger than the diameter of the piston body 51, is baked. The inner periphery of the sleeve 74 is baked.

In this embodiment, the diaphragm 40 is formed integrally with the annular elastic member 60 at its lower inner periphery. In the free state, the diaphragm 40 bulges upward into the cylindrical portion 56.

In this manner, the cylinder sleeve 75 is first inserted from below into the cylindrical body 11 of the base member 10, and then the sleeve 74 supporting the weight 50 via the annular elastic member 60 is inserted, so that the upper end of the cylinder sleeve 75 is annular. The cylindrical body 1 is in contact with the protrusion 13.
Caulk the lower end of 1 inward and attach the upper and lower sleeves 7.
5 and 74 are assembled on the inner periphery of the cylindrical body 11 in a vertically immovable manner.

In the above, the piston ring 71 fitted to the piston body 51 of the weight 50, both guide bushes 7
2, 73 and the cylinder sleeve 75 assembled to the inner periphery of the cylindrical body 11 are both made of a low-friction material, that is, a Teflon (registered trademark) material in the embodiment. Although the ring 71 is in close contact with the guide bush 7
2 and 73 form a small gap as shown in the figure.

Although an orifice 55 is formed in the center of the piston body 51, the orifice 55 does not necessarily need to be provided.

As described above, fluid (liquid in the illustration) is contained in the fluid chamber 2 defined vertically by the piston body 51 of the weight 50.
Enclose.

The weight 50 is constituted by a large-area piston body 51, and a piston ring 71 made of a low-friction material and guide bushes 72, 73 are fitted around the piston body 51, while forming the peripheral wall of the fluid chamber 2. A cylinder sleeve 75 also made of a friction-reducing material is fixed inside the cylindrical body 11, and the weight 50 is fitted into the cylindrical body 11 so as to be able to slide vertically through these low-friction rings 71, 72, 73 and the sleeve 75. In order to make the dynamic magnification in the high frequency vibration region almost zero, even if the area of the vertical 50 is made as large as possible, the weight 50 as the piston body 51 can be kept approximately horizontal, and the sliding resistance can be minimized to ensure smooth movement. It can swing up and down, and therefore the desired vibration isolation effect can be effectively achieved. Moreover, since the weight 50 is supported below by the annular elastic member 60, the thickness of the elastic member 60 in the radial direction can be increased.
Therefore, the floating action is sufficiently smooth.

By the way, in the first embodiment described above, the diaphragm 40 is integrated with the lower inner periphery of the annular elastic member 60, but instead of this, a second embodiment showing the second embodiment is used.
As shown in the figure, a large diameter diaphragm 80 is constructed separately from the annular elastic member 60, and a sleeve 78 separate from the above is baked around the periphery of the diaphragm 80, which supports the weight 50 inserted into the cylindrical body 11. 7
A sleeve 78 that supports the diaphragm 80 is further inserted under the cylindrical body 11 in the same manner as above.
You can also caulk the lower end of the inward. The other configurations are the same as in FIG. 1.

In each of the embodiments, the present invention is applied to a so-called upright fluid-filled mount in which a cylindrical body is integrated on the base member side, but an inverted-type fluid-filled mount in which a cylindrical body is integrated in the mounting member side is also applicable. Of course, the present invention is also applicable to the above. It is also possible to arrange an annular elastic member above the piston body for floatingly supporting the weight. Furthermore, without adding a diaphragm,
The present invention can also be applied to a fluid-filled mount that is configured to be substantially vertically symmetrical with respect to the weight.

As is clear from the above description, according to the present invention,
The area of the weight that is floatingly supported across the fluid chamber is larger than the effective area of the elastic member that connects the mounting member and the base member, and the weight is constituted by a large-area piston body, and the piston body A low-friction ring is fitted around the circumference, and a low-friction sleeve is fixed inside the cylindrical body that makes up the peripheral wall of the fluid chamber, so the dynamic magnification in the high-frequency vibration region is increased to further ensure the high-frequency vibration isolation effect. Even if the area of the weight is made as large as possible in order to make the area approximately zero, the weight can be kept almost horizontal as a piston, and can swing up and down smoothly with as little sliding resistance as possible. The period vibration isolation effect can be effectively achieved.

Note that the low-friction ring and sleeve are not limited to Teflon (registered trademark) material, and may be made of metal.

[Brief explanation of drawings]

1 to 8 show embodiments of the present invention. FIG. 1 is a central vertical sectional view showing a first embodiment of a fluid-filled mount according to the present invention, and FIG. 2 is a second embodiment of the same. 3 is a central vertical sectional view showing the basic configuration of a fluid-filled mount for explaining the basic principle of the present invention, FIG. 4 is a half-cut view showing each effective area of the mount, and FIG. is the model diagram, No. 6
The figure is a vertical cross-sectional view of the test device, and Figure 7 is a diagram of its operation.
FIG. 8 is a frequency-dynamic magnification characteristic diagram, and FIG. 9 is a central vertical sectional view of a conventional fluid-filled mount. In the drawing, 1 is a fluid-filled mount, 2 is a fluid chamber,
10 is a base member, 11 is a cylindrical body, 20 is a mounting member, 30 is an elastic member that connects the base member and the mounting member, S _E is its effective area, 50 is a weight, 51 is a piston body, and S _W is its effective 60 is an elastic member that supports the weight, 71, 72 and 73 are low friction rings, and 75 is a low friction sleeve.

Claims (1)

[Claims] 1 A fluid chamber in which a mounting member connected to a vibration source and a base member for mounting the vibration source are coupled with an elastic member to form a fluid chamber therein, and a weight is floatingly supported across the fluid chamber. In the enclosed mount, the weight is composed of a piston body, and the effective area of the weight, which is determined as the ability to contribute to fluid movement per unit displacement of the weight with the fluid chamber open to the atmosphere, is defined as: The effective area of the elastic member is larger than the ability to contribute to fluid movement per unit relative displacement between the mounting member and the base member in a state open to the atmosphere, and a low-friction ring is fitted around the piston body. Furthermore, a low-friction sleeve is fixed in a cylindrical body that is integrated with the mounting member side or the base member side that constitutes the peripheral wall of the fluid chamber, and the piston body is inserted into the cylindrical body through the low-friction ring and the sleeve. A fluid-filled mount characterized by being slidably fitted.