JPH0425636A - Vibration isolator and method thereof - Google Patents

Abstract

PURPOSE:To enable it to absorb all the vibrations over the extensive frequency by installing a limiting means, limiting a flow of liquid, in at least either of an elastic body equipped with plural small liquid chambers and a limiting passage interconnecting these small liquid chambers. CONSTITUTION:When a vehicle runs at high speed, there is produced a shake vibration. If a control means 60 is so judged that it is at time of shake vibration occurrence by a car speed sensor 62 and an engine speed sensor 64, it operates a stepping motor 48, making a shaft 50 move toward an inner cylinder 12. Consequently, a blocking valve 52 canes into contact with a bottom surface of an orifice member 20, blocking a hollow part 21. In addition, qhwn an engine is idling as well as when car speed is less than 5km/h, there is produced an idling vibration. If the control means 60 judges that it is at time of generating this idling vibration, this control means 60 will not operate the stepping motor 48. Accordingly, the shaft 50 is in a state of being left stopped intact, so that the blocking valve 52 is in no case blocked the hollow part 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration isolating device and a vibration isolating method that are used in engine mounts of vehicles, particularly automobiles, and absorb and damp vibrations from vibration generating parts.

[Conventional technology]

A vibration isolator, which serves as an engine mount, is disposed between the engine and the vehicle body of an automobile to prevent engine vibrations from being transmitted to the vehicle body.

A plurality of small liquid chambers filled with liquid are formed inside the vibration isolator, and these small liquid chambers are communicated with each other through restricted passages. When engine vibration is transmitted to the vibration isolator, the vibration is absorbed by the passage resistance and liquid column resonance when the liquid filled in one small liquid chamber moves through the restriction passage to the other small liquid chamber. It is now possible to do so.

By the way, the vibrations generated in the engine cause the vehicle to reach speeds of up to 70 mph.
There are so-called shake vibrations that occur when the vehicle is traveling at approximately 5 km/h, and so-called idling vibrations that occur when the vehicle is idling or when the vehicle is traveling at approximately 5 km/h.

In general, the shake vibration has a frequency of less than 15 Hz, whereas the idle vibration has a frequency of 20 to 40 Hz, and the frequencies of the shake vibration and idle vibration are different.

However, conventional vibration isolators are effective only when the frequency of generated vibrations is within a predetermined range determined by the opening area and length of the restricted passage, and cannot effectively damp or absorb vibrations at frequencies outside of this predetermined range.

For this reason, with conventional vibration isolators, if the vibration isolator is adjusted to effectively damp shake vibrations, it becomes difficult to effectively damp idle vibrations. There is a problem in that it is difficult to effectively damp shake vibration when adjusting.

[Problem to be solved by the invention]

The present invention takes the above-mentioned facts into consideration and aims to provide a vibration isolating device and a vibration isolating method capable of attenuating and absorbing vibrations over a wide range of frequencies.

[Means to solve the problem]

The invention of claim (1) provides a first member connected to one of a vibration generating section and a vibration receiving section, a second member connected to the other, and the first member and the second member. an elastic body having a plurality of small liquid chambers formed between the plurality of small liquid chambers and filled with liquid; a plurality of restriction passages communicating with the plurality of small liquid chambers; and at least one of the restriction passages provided with an elastic body. The present invention is characterized in that it is provided with a restriction means for restricting the flow of liquid in the restriction passage.

The invention of claim (2) provides a first member connected to one of a vibration generating section and a vibration receiving section, a second member connected to the other, and the first member and the second member. an elastic body having a plurality of small liquid chambers formed between the plurality of small liquid chambers and filled with liquid; a plurality of restriction passages communicating the plurality of small liquid chambers; and at least one of the restriction passages arranged in the elastic body. A vibration isolator is provided with a restriction means for restricting the flow of liquid in the restriction passage, and when vibrations below a predetermined frequency occur, the restriction means restricts the liquid flowing through the restriction passage, and vibrations at a frequency higher than the predetermined frequency are suppressed. The present invention is characterized in that, when this happens, the restriction on the liquid flowing through the restriction passage is released by the restriction means.

[Effect]

In the invention as claimed in claim (1), when the limiting means determines that a vibration of less than a predetermined frequency is occurring, the limiting means restricts the flow of the liquid in the restriction passage in which the limiting means is provided.

As a result, liquid is prevented from passing back and forth between the plurality of small liquid chambers through this restricted passage. Therefore, the liquid passes through the other restricted passages to the plurality of small liquid chambers, and vibrations below a predetermined frequency are absorbed by the resistance and liquid column resonance when the liquid passes through the other restricted passages.

Furthermore, when the limiting means determines that vibrations of a predetermined frequency or higher are occurring, the limiting means does not restrict the flow of the liquid in the restriction passage in which the limiting means is provided. As a result, the liquid can flow back and forth in the small liquid chamber even through the restriction passage provided with the restriction means.

Therefore, the total flow area of the liquid becomes large, and vibrations in a predetermined frequency range are absorbed by the resistance when passing through the restricted passage and the resonance of the liquid column.

In the invention of claim (2), when vibrations less than a predetermined frequency occur, the liquid flowing through the restriction passage is restricted by the restriction means.

As a result, the liquid passes through the other restriction passage, and vibrations below a predetermined frequency are absorbed by the resistance and liquid column resonance when the liquid passes through the other restriction passage.

Furthermore, when vibrations of a predetermined frequency or higher occur, the restriction means releases the restriction on the liquid flowing through the restriction passage. As a result, the liquid flows through any of the restricted passages, and vibrations in a predetermined frequency range are absorbed by the resistance and resonance of the liquid column when passing through the restricted passages.

[First Embodiment] FIG. 4 shows an exploded perspective view of a first embodiment of a vibration isolator according to the present invention. Inside the vibration isolator 10, a cylindrical inner cylinder 12 serving as a 71st member is disposed. A substantially semi-cylindrical outer cylinder 16 serving as a second material is disposed coaxially with the inner cylinder 12. In this embodiment, the inner cylinder 12 is connected to an engine (not shown) as a vibration generator via a bracket. The outer cylinder 16 also has a bracket 17 attached separately to the vehicle body (not shown) as a vibration receiving part.
(See Figure 2).

A main body rubber 14 is provided between the outer peripheral surface of the inner cylinder 12 and the inner peripheral surface of the outer cylinder 16. The main body rubber 14 is the inner cylinder 1
2 and the inner circumferential surface of the outer cylinder 16, respectively, by vulcanization bonding.

A groove portion 16A is formed on the outer peripheral surface of the straight portion 16E of the outer cylinder 16. One end edge 18A of the base plate 18, which is rectangular in plan view, is fitted into this groove 16A. Thereby, as shown in FIG. 2, the base plate 18 is attached to the outer cylinder 16. A recess 18B is formed in the axial center of the base plate 18 and is concave in the opposite direction to the inner cylinder 12, and a circular hole 44 is formed in the axial center of the recess 18B.

As shown in FIG. 2, stepped portions 16B and 16C are continuously formed on the inner circumferential surface of the linear portion of the outer cylinder 16. The orifice member 20 corresponds to these step portions 16B and 16C.
and a diaphragm 22 are provided. The orifice member 20 and the diaphragm 22 are clamped and fixed between the outer cylinder 16 and the base plate 18.

As shown in FIG. 4, the main body rubber 14 has a notch 14.
A is formed, and a liquid chamber 24 is formed by this notch 14A, the outer cylinder 16, and the diaphragm 22. As shown in FIG. 2, this liquid chamber 24 contains liquids such as water and oil.
6 is filled.

The liquid chamber 24 is divided by the orifice member 20 into a main liquid chamber 28 and a sub-liquid chamber 30 as small liquid chambers.

This sub-liquid chamber 30 is made expandable and contractible by the diaphragm 22. Further, an air chamber 23 is formed by the diaphragm 22 and the base plate 18. This air chamber 23 may be communicated with the outside air by forming a through hole or the like in the base plate 18. A recess 20E having a substantially trapezoidal cross section is formed on the diaphragm 22 side of the orifice member 20. A cylindrical depression 21 is formed in the center of the depression 20E.

As shown in FIG. 4, the orifice member 2o is formed into a substantially block shape. As shown in FIG. 2, grooves 32 and 34 are formed in the outer circumferential surface of the orifice member 20 in the vertical direction in FIG. 2 and open toward the stepped portion 16B of the outer cylinder 16. Both longitudinal ends of these grooves 32, 34 are separated from each other by a closure 20F. Furthermore, the widthwise ends of the grooves 32 and the widthwise ends of the grooves 34 are separated from each other by a partition plate 33. Of the grooves 32 and 34, the groove 32 has a larger cross-sectional area.

As shown in FIG. 4, an opening 32 formed in the top plate 2OA of the orifice member 20 is provided at one end of the groove 32 in the longitudinal direction.
An opening 32B formed in the recess 21 is formed at the other end of the groove 32 in the longitudinal direction. Further, one longitudinal end of the groove 34 has an opening 34A formed in the partition plate 33, and the other longitudinal end of the groove 34 has an opening 34A formed in the side surface of the recess 20E of the orifice member 20.
4 and the sub-liquid chamber 30 are respectively formed. As a result, the grooves 32 and 34 respectively communicate the main liquid chamber 28 and the auxiliary liquid chamber 3o.

As shown in FIG. 2, these grooves 32 and 34 are closed at their openings by the outer cylinder 16, thereby forming an idle orifice 38 and a shake orifice 40 as restricted passages. Therefore, since the idle orifice 38 and the shake orifice 40 are formed along the outer periphery of the orifice member 20, the idle orifice 38 and the shake orifice 40 are formed to have a long length in the longitudinal direction.

A blocking valve 52, which is a restricting means capable of closing the recessed portion 21, is attached to the axial center of the diaphragm 22. The diameter of the top plate portion 52B of the closure valve 52 is larger than the diameter of the recessed portion 21. The boss portion 52A of the closure valve 52 is fitted into the diaphragm 22 and bonded by vulcanization, so that the boss portion 52A is integrated with the diaphragm 22.

Further, rubber 54 is vulcanized and adhered to the inner cylinder 12 side of the top plate portion 52B so that when the closing valve 52 closes the recess 21, the recess 21 can be closed in a sealed state. As a result, when the concave portion 21 is closed by the closing valve 52, the liquid 26 is prevented from passing back and forth between the main liquid chamber 28 and the sub-liquid chamber 30 through the idle orifice 38.

As shown in FIG. 1, a stepping motor 48, which is one of the limiting means, is fixed to the outer peripheral surface of the base plate 18. This stepping motor 48 is a type of pulse motor, and its movement stroke is controlled by a control means 60 which is one of limiting means. In this embodiment, when the stepping motor 48 is energized, the shaft 50 extends toward the orifice member 20, and when the stepping motor 48 is not energized, the shaft 50 does not extend toward the orifice member 20.

The control means 60 is driven by the vehicle power source, receives detection signals from at least a vehicle speed sensor 62 and an engine rotation sensor 64, and is capable of detecting vehicle speed and engine rotation speed. This allows the control means 60 to determine whether the vehicle is idling or shaking.

The shaft portion 50 of the stepping motor 48 is formed in the base plate 18 and inserted into the oval hole 44, and its tip end is fitted into the boss portion 52A of the shutoff valve 52.

Next, the operation of the first embodiment will be explained.

When a vehicle runs at a high speed of, for example, 70 to 80 km/h or more, shake vibration (less than 15 Hz) occurs.

The control means 60 uses a vehicle speed sensor 62 and an engine rotation speed sensor 64 to determine whether shake vibration is occurring.

When the control means 60 determines that shake vibration is occurring, the control means 60 operates the stepping motor 48 to move the shaft 50 in the direction of the inner cylinder 12. Therefore, the closing valve 52 comes into contact with the bottom surface of the orifice member 20 and closes the recessed portion 21 .

As a result, the liquid 26 is prevented from passing back and forth between the main liquid chamber 28 and the auxiliary liquid chamber 30 through the idle orifice 38. Therefore, the liquid 26 passes between the main liquid chamber 28 and the sub-liquid chamber 30 only through the shake orifice 40. As a result,
Shake vibrations are absorbed by the resistance and liquid column resonance when the liquid 26 passes through the shake orifice 40.

Also, if the engine is idling or the vehicle speed is 5kph,
If m/L is below 12J, idle vibration (20~30H
z) occurs. The control means 60 uses a vehicle speed sensor 62 and an engine rotation speed sensor 64 to determine whether or not idle vibration is occurring. When the control means 60 determines that idle vibration is occurring, the control means 60 does not operate the stepping motor 48. Therefore, since the shaft 50 remains stopped, the blocking valve 52 does not close the recess 21. As a result, the liquid 26 enters the idle orifice 3
8 and the shake orifice 40, the main liquid chamber 28 and the sub-liquid chamber 30 can be moved back and forth.

Therefore, since the flow path area of the liquid 26 becomes large, it is possible to absorb idle vibrations.

In this embodiment, the base plate 18 covering the diaphragm 22 is caulked and fixed to the outer cylinder, but the base plate I8 may not necessarily be provided.

[Second Embodiment] FIGS. 5 to 7 show a second embodiment of the vibration isolator according to the present invention. Note that the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 6 shows the vibration isolator 210 in an exploded perspective view. This vibration isolator 210 is different from the vibration isolator 10 of the first embodiment and is of a so-called bush type.

A cylindrical outer cylinder 216 coaxially with a cylindrical inner cylinder 212
is installed. In this embodiment, the inner cylinder 212 is connected to an engine (not shown) as a vibration generator via a bracket. Further, the outer cylinder 216 is connected to a vehicle body (not shown) as a vibration receiving part via a bracket.

An intermediate cylinder 218 is formed coaxially with the inner cylinder 212 and the outer cylinder 216 between the inner cylinder 212 and the outer cylinder 216 .

A main body rubber 214 is provided between the inner cylinder 212 and the intermediate cylinder 218. This main body rubber 214 is vulcanized and bonded to the outer peripheral surface of the inner cylinder 212 and the inner peripheral surface of the intermediate cylinder 218. This main body rubber 214 is formed with a notch 214A that is concave toward the inner cylinder 212. This notch 2
14A is closed by the intermediate cylinder 218 and the main liquid chamber 2
It is said to be 28. This main liquid chamber 228 is filled with a liquid 26 such as water or oil.

As shown in FIG. 5, a part of the outer peripheral surface of the intermediate cylinder 218 is formed into a flat plate portion 220. As shown in FIG. A diaphragm 2 is located on the opposite side of the flat plate portion 220 from the main liquid chamber 228.
22 are arranged. This diaphragm 222 is the sixth
As shown in the figure, it is formed into a substantially semi-cylindrical shape.

As shown in FIG. 5, the diaphragm 222 and the flat plate portion 220
A sub-liquid chamber 230 is formed by these. Similar to the main liquid chamber 228, this sub-liquid chamber 230 is also filled with a liquid 26 such as water or oil.

This sub-liquid chamber 230 can be expanded and contracted by a diaphragm 222.

As shown in FIG. 6, a block-shaped box 8242 that is long in the axial direction of the intermediate tube 218 is provided at the intermediate portion of the flat plate portion 220. This box-shaped portion 242 and the flat plate portion 220
A circular hole 244 is formed in the axial direction of the intermediate cylinder 218 so as to span the intermediate cylinder 218 . Furthermore, a square hole 243 communicating with the circular hole 244 is formed in the box-shaped portion 242 .

Passages 232 and 234 are formed around the axis of the intermediate tube 218 inside the circular arc portion 222 and the top plate portion 220 of the intermediate tube 218 . The passage 232 is formed to have a larger cross-sectional area than the passage 234. An opening 232A is formed at one end of the passage 232 and communicates with the main liquid chamber 228,
An opening 232B is formed at the other end of the passage 232 and communicates with the circular hole 244. Thereby, the passage 232 communicates the main liquid chamber 228 and the auxiliary liquid chamber 230.

Further, an opening 234A is formed at one end of the passage 234 and communicates with the main liquid chamber 228, and an opening 234B is formed at the other end of the passage 234 and communicated with the auxiliary liquid chamber 230. As a result, the passage 234 communicates the main liquid chamber 228 and the auxiliary liquid chamber 230 similarly to the passage 232.

As shown in FIG. 7, the passage 232 and the passage 234 are formed so that their elongated directions are parallel to each other, and the passage 232 serves as an idle orifice 238, and the passage 234 serves as a shake orifice 240.

As shown in FIG. 6, a cylindrical rotor 252 is rotatably accommodated in the circular hole 244.

A through hole 254A is provided on the outer peripheral surface 252A of this rotor 252.
, 254B are formed. As shown in FIG. 5, the through hole 254A corresponds to the square hole 243 formed in the box-shaped portion 242, and the through hole 254B corresponds to the opening 232B. Therefore, when the rotor 252 rotates and the through hole 254A corresponds to the square hole 243 and the i through hole 254B corresponds to the opening 232B, the liquid 26 passes through the idle orifice 238 and enters the main liquid chamber 228 and the sub liquid chamber 230. It is possible to go back and forth. Further, when the outer peripheral surface 252A corresponds to the square hole 243 due to the rotation of the rotor 252, the liquid 26
is prevented from passing back and forth between the main liquid chamber 228 and the auxiliary liquid chamber 230 through the idle orifice 238.

A motor 248 is connected to the rotor 252, allowing the rotor 252 to rotate around its axis. The rotation of this motor 248 is controlled by control means 60. This control means 60 is driven by a vehicle power source, receives detection signals from at least a vehicle speed sensor 62 and an engine rotation sensor 64, and is capable of detecting vehicle speed and engine rotation speed.

Next, the operation of the second embodiment will be explained.

When a vehicle runs at a high speed of, for example, 70 to 80 km/h or higher, shake vibrations (less than 15 Hz) occur.

The control means 60 uses a vehicle speed sensor 62 and an engine rotation speed sensor 64 to determine whether shake vibration is occurring or not.

When the control means 60 determines that the shake vibration is generated, the control means 60 operates the motor 248 to rotate the rotor 252 in the clockwise direction in FIG. Therefore, the circumferential surface 252A of the rotor 252 corresponds to the square hole 243, and the square hole 243 is closed.

As a result, liquid 26 is prevented from passing through idle orifice 238 and through main liquid chamber 228 and secondary liquid chamber 230 . Therefore, the liquid 26 passes through the shake orifice 240
The main liquid chamber 228 and the auxiliary liquid chamber 230 are moved back and forth through only the main liquid chamber 228 and the sub liquid chamber 230. Shake vibrations are absorbed by the support and liquid column resonance when the liquid 26 passes through the shake orifice 240.

Also, if the engine is idling or the offshore speed is 5k
When the speed is less than m/h, idle vibration (20 to 407) occurs. The control means 60 uses a vehicle speed sensor 62 and an engine rotation speed sensor 64 to determine whether or not idle vibration is occurring. When the control means 60 determines that idle vibration is occurring, the control means 60 rotates the motor 248 and stops the rotor 252 in the state shown in FIG. Therefore, the through hole 254A of the rotor 252 corresponds to the square hole 243. As a result, the liquid 26 can pass through the idle orifice 238 and the shake orifice 240 and go back and forth between the main liquid chamber 228 and the auxiliary liquid chamber 230.

[Third Embodiment] FIGS. 8 and 9 show a third embodiment of the vibration isolating device according to the present invention. Note that this embodiment is similar to the vibration isolator 10 of the first embodiment, and the same components as the vibration isolator 10 of the first embodiment are designated by the same reference numerals, and the explanation thereof will be omitted.

Two rectangular openings 320 are formed in the base plate 318 which is caulked and fixed to the outer cylinder 16. Diaphragms 322 that close the openings 320 are vulcanized and bonded to the base plate 318.

A rectangular partition 324 is formed between the openings 320 of the base plate 318. A circular hole 326 is formed in the middle portion of this partition portion 324 . 20 round hole 32
6, a boss portion 352A of a blockage valve 352 is inserted. A groove 330.33G whose elongated direction extends along the circumferential direction is formed on the outer peripheral surface of the boss portion 352A. These grooves 33
0 accommodates an O-ring 332.

The other configurations are the same as in the first embodiment.

In this embodiment, the boss portion 352A of the closure valve 52 is not vulcanized and bonded to the diaphragm 322. Therefore, when the stepping motor 48 operates and the blockage valve 352 moves in its axial direction, the diaphragm 322 does not move in accordance with the movement of the blockage valve 352.

As a result, the diaphragm 322 expands and contracts only due to the influence of the hydraulic pressure in the sub-liquid chamber 30, so that the desired attenuation at t1 can be performed more reliably.

Other operations are similar to those in the first embodiment.

Note that the stepping motor 4 of the base plate 318
A cover integrally covering the diaphragm 322 may be provided on the 8-direction side.

In addition, in the first to third embodiments, the cross-sectional area of the idle orifice was formed larger than the cross-sectional area of the shake orifice, but the cross-sectional area of the idle orifice may be equal to or smaller than the cross-sectional area of the shake orifice. .

〔Effect of the invention〕

As explained above, although the present invention is a single vibration isolator, it has the excellent effect of effectively damping and absorbing shear vibrations over a wide range of frequencies.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the vibration isolator according to the present invention, FIG. 1 is a sectional view taken along line I-I in FIG. 3, and FIG. 2 shows a state in which the bracket is attached to the outer cylinder. Fig. 3 is a sectional view taken along line ■-■, Fig. 3 is an overall perspective view, Fig. 4 is an exploded perspective view with a part cut away, and Figs. Embodiment 2 is shown, FIG. 5 is a sectional view corresponding to FIG. 2, FIG. 6 is an exploded perspective view with a part cut away, and FIG.
The figures are a view taken along the line shown in FIG. 6, and FIGS. FIG. 9 is an exploded perspective view with a portion cut away. DESCRIPTION OF SYMBOLS 10... Vibration isolator, 12... Inner cylinder (first member), 14... Main body rubber (elastic body), 16... Outer cylinder (second member), 24... Liquid Chamber, 26...Liquid, 28...Main liquid chamber (small liquid chamber), 30...Sub-liquid chamber (small liquid chamber), 38...Idle orifice (restriction passage), 40...
Shake orifice (restriction passage), 48...Stepping motor (restriction means), 52...Shutoff valve (restriction means), 60...Control means (restriction means).

Claims (2)

[Claims] (1) A first device connected to one of the vibration generating section and the vibration receiving section.
a second member connected to the other member; an elastic body comprising a plurality of small liquid chambers formed between the first member and the second member and filled with liquid; The present invention is characterized by comprising a plurality of restriction passages that communicate the plurality of small liquid chambers, and a restriction means provided in at least one of these restriction passages to restrict the flow of liquid in this restriction passage. Anti-vibration device. (2) The first part connected to one of the vibration generating part and the vibration receiving part
a second member connected to the other member; an elastic body comprising a plurality of small liquid chambers formed between the first member and the second member and filled with liquid; A vibration isolator including a plurality of restriction passages communicating a plurality of small liquid chambers, and a restriction means disposed in at least one of the restriction passages to restrict the flow of liquid in the restriction passage. ,
When vibrations less than a predetermined frequency occur, the restriction means restricts the liquid flowing through the restriction passage, and when vibrations of a predetermined frequency or higher occur, the restriction means releases the restriction on the liquid flowing through the restriction passage. Shaking method.