JP4001230B2 - Liquid-filled vibration isolator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid-filled vibration isolator.
[0002]
[Prior art]
As shown in FIG. 8, the liquid-filled vibration isolator includes a first attachment 1 attached to a vibration body such as an automobile engine and a round tubular second attachment 2 attached to a vehicle body frame from a rubber-like elastic material. The diaphragm 5 for forming the liquid chamber 4 is provided between the anti-vibration base 3 and the anti-vibration base 3, and the liquid chamber 4 is connected to the first fixture by the thin partition plate 20. A partition portion 8 is provided to partition the chamber portion 6 and the second liquid chamber portion 7, and an orifice 22 that connects the first liquid chamber portion 6 and the second liquid chamber portion 7 is formed. With this structure, it is possible to obtain the liquid flow effect of both the liquid chamber portions 6 and 7 and the vibration isolation effect of the vibration isolation base 3 to suppress the transmission of vibration from the vibrating body to the vehicle body.
[0003]
Further, in addition to these structures, a stopper portion 10 that projects outwardly in the radial direction of the second fixture 2 is formed on the second fixture 2, and the stopper portion 10 is attached to the shaft of the second fixture 2. A plate-like stopper member 11 received in the center direction is cantilevered on the first fixture 1 side to prevent excessive compression / extension (large displacement) of the vibration-proof base 3.
[0004]
In the liquid-filled vibration isolator having the above structure, if the natural frequency of each part is within the range of the vibration body during normal operation, each part resonates during normal operation, and the liquid-filled vibration-proof vibration device The spring constant of the device is increased, so that a sufficient anti-vibration effect cannot be obtained.
[0005]
Therefore, conventionally, the stopper member 11, the partition plate 20, and the vibration isolation base 3 have been formed so that their natural frequencies are higher than the range of the frequencies.
[0006]
[Problems to be solved by the invention]
According to the above-described conventional configuration, resonance of the stopper member 11, the partition plate 20, and the vibration isolating base 3 can be avoided during normal operation, and an increase in the spring constant of the liquid-filled vibration isolator can be avoided, resulting in a vibration isolating effect. Although it can be sufficiently obtained, since the stopper member 11, the partition plate 8, and the vibration isolating base 3 are all formed so that their natural frequencies are high, the vibration frequency of the vibrating body is within the above range. When the operating state exceeds the limit, all of the stopper member 11, the partition plate 20, and the vibration isolating base 3 resonate all at once, and the spring of the liquid filled type vibration isolator as shown by a one-dot chain line (conventional example) in FIG. The constant suddenly increased and the anti-vibration performance was likely to be greatly deteriorated (FIG. 5 is described in detail in the [Embodiment] section).
[0007]
An object of the present invention is to provide a liquid-filled vibration isolator that does not easily deteriorate the vibration isolating performance even when the operating state is such that the vibration frequency of the vibrating body exceeds the range during normal operation.
[0008]
[Means for Solving the Problems]
The structure of the invention according to claim 1 is:
A diaphragm that connects the first mounting bracket and the cylindrical second mounting bracket via a vibration-proof base made of a rubber-like elastic material, and forms a liquid chamber between the second mounting bracket and the vibration-proof base. Providing a partition part for partitioning the liquid chamber into a first liquid chamber part and a second liquid chamber part with a thin partition plate, forming an orifice for communicating the first liquid chamber part and the second liquid chamber part,
A stopper member that protrudes radially outward of the second mounting bracket is formed on the second mounting bracket side, and a stopper member that receives the stopper portion in the axial direction of the second mounting bracket Configured to be cantilevered on the first mounting bracket side,
The second mounting bracket is composed of a cylindrical metal part to be vulcanized and bonded to the vibration-proof base, and a bottom metal part fixed by caulking to the cylindrical metal part,
A rubber film portion connected to the lower end portion of the vibration-proof base is vulcanized and bonded to the inner peripheral surface of the cylindrical fitting portion,
The partition portion is constructed by laying the partition plate between the inner peripheral walls of a round tube portion to be fitted into the cylindrical metal fitting portion of the second mounting bracket. A metal plate is pressed and formed integrally.
The round cylinder part has both upper and lower ends projecting radially outward, and the upper and lower ends projecting from the round cylinder part are fitted into the rubber film part of the cylindrical metal part,
Even if the stopper member or the vibration isolating base resonates, the partition plate is provided with a rigidity increasing portion for avoiding the resonance of the partition plate,
The rigidity increasing portion is disposed radially inward from the inner peripheral surface of the round cylindrical portion between the projecting upper and lower end portions, and the rigidity increasing portion and the inner peripheral surface of the round cylindrical portion are Separated in the radial direction,
When vibration of 700 Hz to 950 Hz is applied, the spring constant is within 3000 N / mm .
[0010]
The structure of the invention according to claim 2 is the structure of the invention according to claim 1,
The rigidity increasing portion is formed by superposing and fixing a thin plate material on at least one of the two plate surfaces of the partition plate.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
[First Embodiment]
1, 2 and 4 show a liquid filled type vibration isolator for an automobile. In this liquid-filled vibration isolator, a plate-shaped first mounting bracket 1 attached to the engine and an upper end portion of a round cylindrical second mounting bracket 2 attached to a vehicle body frame below the engine are made of a rubber-like elastic material. The diaphragm 5 is formed on the second fixture 2 so as to form a liquid chamber 4 between the anti-vibration base 3 and the anti-vibration base 3. The liquid chamber 4 is connected to the upper first liquid chamber 6 and the lower part. A partition portion 8 is provided to partition the second liquid chamber portion 7 on the side, and the liquid chamber portions 6 and 7 are filled with liquid.
[0016]
A stoppered portion 10 that projects outward in the radial direction of the second mounting bracket 2 is formed on the upper end side of the second mounting bracket 2, and the stoppered portion is mounted in a state where the first mounting bracket 1 is attached to the engine. A plate-like stopper fitting 11 (corresponding to a stopper member) that receives 10 in the axial direction (vertical direction) and the lateral direction of the second attachment fitting 2 is the first attachment fitting 1 side. A separate body is provided to prevent excessive compression / elongation (large displacement) of the vibration-proof substrate 3.
[0017]
The first mounting bracket 1 is mounted on the engine by screwing an upward mounting bolt 12 projecting from the center of the first mounting bracket 1 into an internal thread portion on the engine side. Reference numeral 19 denotes an upward positioning pin protruding from the first mounting bracket 1. The positioning pin 19 can accurately determine the position of the first fixture 1 relative to the engine side.
[0018]
The second mounting bracket 2 includes a cylindrical metal part 13 to which the vibration-proof base 3 is vulcanized and bonded, and a bottom metal part 14 that is caulked and fixed to the cylindrical metal part 13. A downward mounting bolt 15 projecting from the body is screwed into a female screw portion on the vehicle body frame side and attached to the vehicle body frame.
[0019]
The anti-vibration base 3 is formed in the shape of a truncated cone, and its upper end surface is vulcanized and bonded to the first mounting bracket 1, and its lower end outer peripheral portion is vulcanized and bonded to the upper end of the cylindrical bracket portion 13. ing. The rubber film portion 16 connected to the lower end portion of the vibration isolating base 3 is vulcanized and bonded to the inner peripheral surface of the cylindrical metal portion 13.
[0020]
As shown in FIG. 2, the diaphragm 5 includes a partially spherical rubber film body 17 and a ring fitting 18 on the outer peripheral side thereof.
[0021]
The partition portion 8 includes a round tube portion 9 to be fitted in the cylindrical metal portion 13, a partition plate 20 between inner peripheral walls slightly below the upper end of the round tube portion 9, and a lower mounting flange 21. The thin plate is formed by pressing a thin metal plate (that is, the partition portion 8 is formed by dividing the partition plate 20 into the first liquid chamber portion 6 and the second liquid chamber portion 7 by a round tube portion. 9 is constructed between 9 inner peripheral walls).
[0022]
The round cylindrical portion 9 has both upper and lower ends projecting radially outward, and the upper end portion and the lower end portion on the base side of the mounting flange 21 are located inside the rubber film portion 16 of the cylindrical fitting portion 13. It is fitted. Between the peripheral wall of the round cylinder part 9 and the rubber film part 16 of the cylindrical metal part 13, an orifice 22 is formed for communicating the first liquid chamber part 6 and the second liquid chamber part 7. The mounting flange 21 is caulked and fixed to the cylindrical fitting 13 together with the ring fitting 18 of the diaphragm 5 and the bottom fitting 14 of the second fitting 2.
[0023]
Further, the partition plate 20 is provided with a rigidity increasing portion 32. As shown in FIG. 3, the rigidity increasing portion 32 is provided with a thin metal disk 33 (corresponding to a thin plate material) on the upper surface of the partition plate 20. 20 is concentrically polymerized and fixed by welding. The diameter of the circular plate 33 is about two thirds of the diameter of the partition plate 20, and the wall thickness is the same as that of the partition plate 20.
[0024]
With the above structure, when a large amplitude vibration having a low frequency is generated, the liquid is attenuated by flowing between the liquid chambers 6 and 7 through the orifice 22, and a small amplitude vibration having a high frequency. When this occurs, the vibration is attenuated by the reciprocating deformation of the partition plate 20 without the liquid passing through the orifice 22.
[0025]
The stopper portion 10 includes a vibration-proof base portion in which a protruding piece 23 having a rectangular shape in a plan view on the upper end side of the cylindrical fitting 13 and a reinforcing fitting plate 24 below the protruding piece 23 are extended correspondingly. 25.
[0026]
The stopper fitting 11 is formed by integrally connecting a superposition portion 26 that overlaps the first attachment fitting 1 from above and a stopper action portion 27 that surrounds the stopper portion 10 from both the upper and lower directions and the lateral outer side. It is formed in a letter shape. Further, both end portions in the width direction of the overlapping portion 26 are bent downward to form reinforcing first ribs 28, and bolt insertion holes 29 through which the mounting bolts 12 are inserted and positioning pins 19 are inserted into the overlapping portion 26. A pin insertion hole 30 to be inserted is formed. The stopper acting portion 27 is also formed with a second rib 31 for reinforcement by raising its central portion in the width direction. Thereby, the intensity | strength of the stopper metal fitting 11 can be raised. In the stopper fitting 11 having the above structure, the overlapping portion 26 is sandwiched between the first attachment fitting 1 and the engine-side attachment portion and is cantilevered on the first attachment 1 side.
[0027]
As shown in FIG. 5, the present inventor has experimentally determined the relationship between the frequency applied to the liquid-filled vibration isolator (Example 1) having the above structure and the spring constant of the liquid-filled vibration-proof device. Similarly, the relationship between the vibration frequency applied to the liquid-filled vibration isolator (conventional example) in which the rigidity increasing portion 32 is not provided on the partition plate 20 and the spring constant of the liquid-filled vibration isolator is obtained through experiments. Compared.
[0028]
[Experimental conditions]
Vibrations of 50 Hz to 1000 Hz and + −9.8 m / s ² were applied to the liquid-filled vibration isolator, and the spring constant of the liquid-filled vibration isolator for each frequency was measured.
[0029]
[results of the experiment]
In the conventional example, when a vibration of 50 Hz to 700 Hz is applied, the spring constant becomes a substantially constant value within 1500 N / mm. However, when a vibration exceeding 700 Hz is applied, the spring constant starts to increase greatly and reaches a maximum at 900 Hz vibration. Of 9000 N / mm.
[0030]
On the other hand, in Example 1, when a vibration of 50 Hz to 700 Hz is applied, the spring constant becomes a substantially constant value of 1000 N / mm to 1250 N / mm, and when a vibration of 700 Hz to 950 Hz is applied, 3000 N / mm. Even if vibration of 1000 Hz was applied, it could be suppressed to 4000 N / mm or less.
[0031]
[Second Embodiment]
As shown in FIGS. 6 and 7, the partition plate 20 is provided with a rigidity increasing portion 32 having a structure different from that of the first embodiment, and the rigidity increasing portion 32 is formed on the partition plate 20 by pressing. The third rib 34 is formed to bulge upward. The six third ribs 34 are radially arranged around the axis of the partition plate 20 every 60 degrees. Other structures are almost the same as those of the liquid-filled vibration isolator of the first embodiment, and the description of the structure is omitted.
[0032]
As shown in FIG. 5, the present inventor obtained the relationship between the vibration frequency applied to the liquid-filled vibration isolator having the above-described structure (Example 2) and the spring constant of the liquid-filled vibration-proof device by experiments. It was compared with the experimental results of the same as the conventional example in the first embodiment. The experimental conditions and the results of the conventional experiment are as described in the first embodiment.
[0033]
In Example 2, when a vibration of 50 Hz to 700 Hz was applied, the spring constant became a substantially constant value of 1000 N / mm to 1600 N / mm, and even when a vibration exceeding 700 Hz was applied, the spring constant could be suppressed within 6300 N / mm. .
[0034]
[Another embodiment]
The disc 33 may be superposed on the lower surface of the partition plate 20, or the pair of discs 33 may be superposed separately on the upper and lower surfaces. The number and shape of the third ribs 34 are not limited to the number and shape in the above embodiment. Further, the third rib 34 may be formed to bulge below the partition plate 20. For example, the third rib 34 that bulges upward and the third rib 34 that bulges downward are arranged adjacent to each other. It may be installed. The third rib 34 may be formed by means other than press working. The numerical values given in the above embodiment are merely examples, and may be different numerical values.
[0035]
【The invention's effect】
According to the configuration of the first aspect, since the rigidity increasing portion is provided in the partition plate, the operation state is such that the vibration frequency of the vibration body exceeds the vibration frequency of the vibration body during normal operation. Even if the vibration isolator base resonates, the partition plate can be prevented from resonating. Compared to the conventional structure in which all of the partition plate, the vibration isolator base, and the stopper member resonate, the liquid can be operated in the above operating state. An increase in the spring constant of the enclosed vibration isolator can be suppressed.
[0036]
Accordingly, it is possible to provide a liquid-filled type vibration isolator in which the vibration isolating performance is unlikely to deteriorate even when the operating state is such that the frequency of the vibrating body exceeds the frequency range of the vibrating body during normal operation. .
[0037]
According to the configuration of claim 1 , the partition portion is configured by laying the partition plate between the inner peripheral walls of the round tube portion fitted into the cylindrical metal portion of the second mounting bracket, and the round tube portion and the partition plate Means that a single metal plate is integrally formed by pressing, so that the partition portion can be easily formed and the manufacturing cost can be reduced.
[0038]
According to the configuration of the second aspect, since the rigidity increasing portion is formed by superposing and fixing the thin plate material on at least one of the two plate surfaces of the partition plate, the structure of the rigidity increasing portion is simplified. Can be
[0039]
In hydraulic antivibration device as set forth in claim 1, to configure the partition portion, bridged the partition plate between the inner circumferential wall of the round tube portion that makes fitted in the second fitting gold again and again, round There is a structure in which the cylinder part and the partition plate are integrally formed by pressing one metal plate. For example, if the partition plate is made thicker by increasing the rigidity of the partition plate, the metal plate press However, in the configuration of claim 2 , the rigidity increasing portion superimposes a thin plate material on at least one of the two plate surfaces of the partition plate. Since they are fixedly configured, the above-mentioned problems can be avoided, and it is not necessary to change to a structure different from the above-described structure formed by pressing one metal plate.
[Brief description of the drawings]
FIG. 1 is a plan view of a liquid-filled vibration isolator. FIG. 2 is a longitudinal front view of the liquid-filled vibration isolator. FIG. 3 is a view in FIG. FIG. 5 is a diagram showing the relationship between the vibration frequency of the liquid-filled vibration isolator and the spring constant. FIG. 6 is a longitudinal front view of the liquid-filled vibration isolator of the second embodiment. FIG. 8 is a longitudinal front view showing a conventional technique.
DESCRIPTION OF SYMBOLS 1 1st fixture 2 2nd fixture 3 Anti-vibration base | substrate 4 Liquid chamber 5 Diaphragm 6 1st liquid chamber part 7 2nd liquid chamber part 8 Partition part 10 Stopper part 11 Stopper member 22 Orifice 32 Rigidity increase part 33 Thin plate material 34 Ribs

Claims (2)

A diaphragm that connects the first mounting bracket and the cylindrical second mounting bracket via a vibration-proof base made of a rubber-like elastic material, and forms a liquid chamber between the second mounting bracket and the vibration-proof base. Providing a partition part for partitioning the liquid chamber into a first liquid chamber part and a second liquid chamber part with a thin partition plate, forming an orifice for communicating the first liquid chamber part and the second liquid chamber part,
A stopper member that protrudes radially outward of the second mounting bracket is formed on the second mounting bracket side, and a stopper member that receives the stopper portion in the axial direction of the second mounting bracket Configured to be cantilevered on the first mounting bracket side,
The second mounting bracket is composed of a cylindrical metal part to be vulcanized and bonded to the vibration-proof base, and a bottom metal part fixed by caulking to the cylindrical metal part,
A rubber film portion connected to the lower end portion of the vibration-proof base is vulcanized and bonded to the inner peripheral surface of the cylindrical fitting portion,
The partition portion is constructed by laying the partition plate between the inner peripheral walls of a round tube portion to be fitted in the cylindrical metal portion of the second mounting bracket, and the round tube portion and the partition plate are a single sheet. A metal plate is pressed and formed integrally.
The round cylinder part has both upper and lower ends projecting radially outward, and the upper and lower ends projecting from the round cylinder part are fitted into the rubber film part of the cylindrical metal part,
Even if the stopper member or the vibration isolating base resonates, the partition plate is provided with a rigidity increasing portion for avoiding the resonance of the partition plate,
The rigidity increasing portion is disposed radially inward from the inner peripheral surface of the round cylindrical portion between the projecting upper and lower end portions, and the rigidity increasing portion and the inner peripheral surface of the round cylindrical portion are Separated in the radial direction,
A liquid-filled vibration isolator in which the spring constant is within 3000 N / mm when vibration of 700 Hz to 950 Hz is applied .   2. The liquid filled type vibration damping device according to claim 1, wherein the rigidity increasing portion is configured by superposing and fixing a thin plate material on at least one of the two plate surfaces of the partition plate.

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