JP3050243B2 - Anti-vibration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration device for use in vehicles, general industrial machines and the like, which absorbs and attenuates vibration from a vibration generator.

[0002]

2. Description of the Related Art In an automobile engine, an anti-vibration device as an engine mount is disposed between the engine and a vehicle body.
The vibration of the engine is prevented 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 communicate with each other through a restriction passage. Then, when the vibration of the engine is transmitted to the vibration isolator, the vibration is absorbed by the passage resistance and the liquid column resonance when the liquid filled in the small liquid chamber moves through the restricted passage to the other small liquid chamber. It is supposed to be.

The vibrations generated in the engine include so-called shake vibration generated when the vehicle is running at high speed and so-called idle vibration generated when the vehicle is idling and when the vehicle is running at about 5 km / h. Etc.

In general, the shake vibration has a frequency of 15
Hz, while idle vibration has a frequency of 20-
The frequency is 40 Hz, which is different between the shake vibration and the idle vibration.

However, the conventional vibration damping device is effective only when the frequency of the generated vibration is within a predetermined range determined by the opening area and length of the restriction passage, and effectively attenuates the vibration at frequencies other than the predetermined range. Cannot be absorbed.

For this reason, in the conventional vibration isolator, if the vibration isolator is adjusted so as to effectively attenuate the shake vibration, it becomes difficult to effectively attenuate the idle vibration, and in order to attenuate the idle vibration effectively. Adjusting the vibration isolator makes it difficult to effectively damp shake vibration.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a vibration isolator capable of damping and absorbing vibrations over a wide frequency range.

[0009]

According to a first aspect of the present invention, there is provided a vibration isolator connected to one of a vibration generator and a vibration receiver and a cylindrical member connected to the other of the vibration generator and the vibration receiver. An elastic body that connects an outer peripheral portion to an opening end of the cylindrical member so as to close one opening of the cylindrical member, connects the connecting member to a central portion, and deforms when vibration occurs. ,
A main liquid chamber that can expand and contract with the elastic body as a part of a partition, a first sub liquid chamber that is isolated from the main liquid chamber, and a partition member that separates the main liquid chamber and the first sub liquid chamber. A first restriction passage formed in the partition member and communicating the main liquid chamber and the first sub liquid chamber, and a second eye control passage formed in the partition member and communicating with the main liquid chamber, A second sub-liquid chamber provided in a part of the second restriction passage, a diaphragm forming a partition of the second sub-liquid chamber, and a diaphragm disposed on a side opposite to the second sub-liquid chamber side of the diaphragm; When the internal pressure is reduced with respect to the atmospheric pressure, the diaphragm is brought into close contact with the inner wall side and substantially disappears, thereby preventing expansion and contraction of the second sub liquid chamber. Bei air chamber for preventing the flow of liquid, and negative pressure means that the interior of the air chamber to a negative pressure, the
The air chamber is provided outside the tubular member .

[0010]

According to the vibration isolator of the first aspect, for example, when the connecting member is connected to the vibration source and the cylindrical member is connected to the vibration receiving portion, the vibration is applied to the connecting member, the elastic body, and the cylindrical member. It is supported by the vibration receiving part through the. At this time, the vibration is absorbed not only by the resistance due to the internal friction of the elastic body but also by the passage resistance of the liquid flowing through the first restriction passage or the second restriction passage or the liquid column resonance. When the frequency of the vibration is lower than the predetermined frequency, the inside of the air chamber is made to have a negative pressure by the negative pressure means, and the diaphragm constituting the partition wall of the second sub liquid chamber formed in the second restriction passage is provided on the inner wall of the air chamber. Closely fix. As a result, the air chamber substantially disappears, and the second sub liquid chamber cannot be expanded or contracted. For this reason, the liquid does not flow through the second restriction passage, and there is no liquid passage resistance in the second restriction passage.
As a result, the liquid flows through the first restriction passage, and vibrations below a predetermined frequency are absorbed by resistance and liquid column resonance when passing through the first restriction passage.

When the frequency of the vibration becomes higher than the predetermined frequency and the first restriction passage is clogged, the inside of the air chamber is not made negative by the negative pressure means. The diaphragm becomes elastically deformable away from the inner wall of the air chamber,
The second auxiliary liquid chamber can be expanded and contracted. As a result, the liquid flows through the second restriction passage, and the vibration at or above the predetermined frequency is absorbed by the liquid going forward resonance when the liquid passes through the second restriction passage.

Further, the air chamber is provided outside the tubular member.
Because there is no risk of complicating the interior of the vibration isolator,
The degree of freedom in the design of the part structure increases.

Reference Example Before describing an embodiment of a vibration isolator according to the present invention, a vibration isolator according to a reference example will be described with reference to FIGS.

FIG. 4 is an exploded perspective view of a vibration isolator 100 of a so-called bush type.

An outer cylinder 16 having a cylindrical shape is disposed coaxially with the inner cylinder 12 having a substantially cylindrical shape. In this reference example, inner cylinder 1
2 is connected to an engine 76 (see FIG. 1) as a vibration generating unit via a bracket (not shown), and the outer cylinder 16 is connected to a vehicle body (not shown) as a vibration receiving unit via a bracket 17 (see FIG. 1). It has become.

The question of the inner cylinder 12 and the outer cylinder 16 is as follows.
An intermediate cylinder 18 is arranged coaxially with the cylinder 6. Ring-shaped large-diameter portions 18A and 18B are formed at both ends of the intermediate cylinder 18 in the axial direction. The intermediate portion of the intermediate cylinder 18 in the axial direction is reduced in diameter as shown in FIG.
It has been.

As shown in FIG. 4, a rubber body 14 is stretched between the inner cylinder 12 and the intermediate cylinder 18 as an elastic body. The main rubber 14 is vulcanized and bonded to the outer peripheral surface of the inner cylinder 12 and the inner peripheral surface of the intermediate cylinder 18.

As shown in FIGS. 1 and 2, the main rubber 14 has a notch 1 cut out toward the inner cylinder 12.
4A are formed. The main liquid chamber 28 is formed by the notch 14A and the top plate 22A of the partition plate 22 arranged corresponding to the notch 20A formed in the small diameter portion 20 of the intermediate cylinder 18. The main liquid chamber 28 is filled with a liquid 26 such as ethylene glycol.

As shown in FIG. 4, an orifice member 34 made of a rubber material is vulcanized and bonded to a portion of the small-diameter portion 20 of the intermediate cylinder 18 other than the cutout portion 20A. The orifice member 34 is formed in a substantially arc shape, and the outer peripheral surface has the same outer diameter as the large diameter portions 18A and 18B of the intermediate cylinder 18.

As shown in FIGS. 2 to 4, a substantially C-shaped groove 36 is formed in the circumferential direction of the intermediate cylinder 18 on the side of the orifice member 34 in the direction of the large diameter portion 18A. As shown in FIGS. 3 and 4, an opening 36 </ b> A is formed at one longitudinal end of the groove 36 and communicates with the main liquid chamber 28. Also,
As shown in FIG. 1, the other end of the groove 36 is inserted into an opening 22B formed in the partition plate 22, and an opening 36B is formed in the other end.

As shown in FIG. 4, a substantially arc-shaped groove 38 having a large groove width is formed on the orifice member 34 in the direction of the large diameter portion 18B of the intermediate cylinder 18. This groove 38 is the groove 36
And the longitudinal directions are parallel to each other. As shown in FIGS. 1 and 4, a portion of the groove 38 corresponding to the flat portion 20B of the small diameter portion 20 of the intermediate cylinder 18 is a flat portion 38A, and a portion corresponding to the arc portion 20C of the small diameter portion 20 is an arc portion. 38B. An upright surface 38C is formed at the end of the flat portion 38A opposite to the arc portion 38B. An opening 38 </ b> D is formed at one longitudinal end of the groove 38, and the groove 38 communicates with the main liquid chamber 28. As shown in FIG. 2, the sectional area of the groove 38 is set to be considerably larger than the sectional area of the groove 36.

As shown in FIG. 1, a thin film rubber 40 as an elastic body is vulcanized and bonded to the inner peripheral surface of the outer cylinder 16. Therefore, when the intermediate cylinder 18 is inserted into the outer cylinder 16, the large-diameter portions 18A and 18B of the intermediate cylinder 18 and the orifice member 3
The outer peripheral surface of the thin film 4 is pressed against the thin film rubber 40. Thus, the groove 36 is the shake orifice 30 as a first restriction passage, and the groove 38 is the idle orifice 32 as a second restriction passage having a larger diameter than the shake orifice 30.

The portion of the thin film rubber 40 corresponding to the partition plate 22 and the portion corresponding to the flat portion 38A are not vulcanized and bonded to the outer cylinder 16, but are respectively bonded to the diaphragms 42, 4
It is set to 4. The diaphragm 42 forms a first sub liquid chamber 46 as a small liquid chamber together with the partition plate 22. The first sub liquid chamber 46 is also filled with the liquid 26 such as ethylene glycol as in the main liquid chamber 28. The opening 36B of the groove 36 corresponds to the first sub liquid chamber 46,
The groove 36 communicates with the first sub liquid chamber 46.

An air chamber 43 is formed by the diaphragm 42 and the outer cylinder 16, and the first sub liquid chamber 46 can be expanded and contracted by enabling the movement of the diaphragm 42. A circular hole 47 is formed coaxially in the outer cylinder 16 and the bracket 17 corresponding to the air chamber 43 so as to communicate with the outside air.

As shown in FIG. 1, inside the idle orifice 32, a second sub-liquid chamber 48 is formed by a flat portion 38A of a groove 38 of the orifice member 34, a rising surface 38C and a diaphragm 44. This second sub liquid chamber 48
The main liquid chamber 28 is also filled with a liquid 26 such as ethylene glycol.

The outer cylinder 16 corresponding to the diaphragm 44
The bracket 17 has coaxial circular holes 50 and 51 formed therein. An axial end 52 </ b> A of the pipe 52 is inserted into each of the circular holes 50 and 51.

As shown in FIG. 1, the other end 52B of the pipe 52 is connected to an intake manifold 70 of an engine 76. Further, an enlarged diameter portion 54 in which the inner diameter of the pipe 52 is set to be large is formed at an intermediate portion of the pipe 52,
Prevents air damping.

The intake manifold 70 is connected to a cylinder 72 via a suction valve 74. Therefore, when the piston 78 as the negative pressure means moves in the direction away from the suction valve 74 (downward in FIG. 1), the suction valve 74 is opened, and the inside of the intake manifold 70 becomes negative pressure. Thereby, the inside of the pipe 52 and the air chamber 43 becomes negative pressure.

A solenoid valve 5 as a negative pressure means is provided between the enlarged diameter portion 54 of the pipe 52 and the intake manifold 70.
6 is attached. This solenoid valve 56 is
0 to be controlled. Solenoid valve 5
6, a movable iron core 56B is provided in the electromagnetic coil 56A by an exciting current.
Are sucked and separated from each other. As a result, the valve body 56C connected to the movable core 56B is
When the magnetic core 6B is attracted by the electromagnetic coil 56A, it retreats from the inside of the pipe 52, and when the movable core 56B is separated from the electromagnetic coil 56A, it advances into the pipe 52.

Therefore, if the valve body 56C of the solenoid valve 56 does not block the pipe 52, the pressure in the pipe 52 and the air chamber 43 becomes negative. When the valve body 56C advances into the pipe 52 and shuts off the pipe 52, the pipe 52 and the air chamber 43 are prevented from becoming negative pressure.

The control means 60 is driven by a vehicle power supply and receives at least detection signals from a vehicle speed sensor 62 and an engine rotation sensor 64 to detect the vehicle speed and the engine speed. Thus, the control means 60 determines whether the vehicle is idling or shaking.

Next, the operation of the reference example will be described.

When a vehicle equipped with the anti-vibration device 100 according to the reference example as an engine mount runs at, for example, 70 to 80 km / h, shake vibration (less than 15 Hz) may occur.
The control means 60 determines whether or not a shake vibration has occurred based on the vehicle speed sensor 62 and the engine speed sensor 64. When the control means 60 determines that shake vibration has occurred, the control means 60 energizes the solenoid valve 56. Therefore, the movable iron core 56B is attracted by the electromagnetic coil 56B and the pipe 5
2 is not shut off by the valve body 56C. As a result, the piston 78 of the engine 76 in the air chamber 43
By moving in the direction away from 4, a negative pressure is created. Therefore, the diaphragm 44 comes into close contact with the inner peripheral surface of the outer cylinder 16 as shown by the imaginary line in FIG. As a result, there is no flow of the liquid 26 in the idle orifice 32 without forming the expandable and contractable second sub liquid chamber 48 in the idle orifice 32.

Accordingly, the liquid 26 contains the shake orifice 3
The main liquid chamber 28 and the first sub liquid chamber 46 pass back and forth only through zero. Moreover, at this time, since the cross-sectional area of the shake orifice 30 through which the liquid 26 passes is small, shake resistance is absorbed by resistance and liquid column resonance when the liquid 26 passes through the shake orifice 30.

When the engine is idling or the vehicle speed is 5 km / h or less, the idle vibration (20
４０40 Hz). The control means 60 determines whether or not idle vibration has occurred based on the vehicle connection sensor 62 and the engine speed sensor 64. If the control means 60 determines that idle vibration has occurred, the control means 60 does not energize the solenoid valve 56, so that the movable iron core 56B is not attracted by the solenoid coil 56B. Therefore, the pipe 52 is provided with a valve body 56C.
The interior of the air chamber 43 is
The piston 78 does not fall into a negative pressure state by the downward movement of FIG.

As a result, the diaphragm 44 approaches the plane portion 38A of the groove 38 (the state shown by the solid line in FIG. 1), and a second sub-liquid chamber 48 that can expand and contract is formed in the idle orifice 32. Therefore, even if the liquid 26 does not pass through the shake orifice 30 due to the clogged state of the shake orifice 30 due to the idle vibration, the liquid 26 passes through the idle orifice 32 having a large flow path area and passes through the main liquid chamber 28. And back and forth between the second sub liquid chambers 48. Therefore, idle vibration can be reliably absorbed by the liquid column resonance of the liquid 26.

[0037]

EXAMPLES Next, an embodiment of a vibration isolator 10 according to the present invention in accordance with FIGS.

The same components as those of the above-described reference example are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 5, mounting bolts 214 project from the bottom of the bottom plate 212 of the vibration isolator 10 and are fixed to a vehicle body (not shown) as an example.

The periphery of the bottom plate 212 is a right-angled cylindrical upright wall portion 212A, and a right-angled flange portion 212B is continuously formed at the upper end of the upright wall portion 212A.

The lower end of an outer cylinder 216 as a cylindrical member fixed to the bottom plate 212 is fixed by caulking to the flange portion 212B. The flange portion 212B and the outer cylinder 21
A peripheral edge of the diaphragm 218 is sandwiched between the lower end of the diaphragm 6 and the lower end of the diaphragm 6. The diaphragm 218 and the bottom plate 21
An air chamber 220 is provided between the air chambers 2 and 2, and is communicated with the outside as needed.

The upper end of the outer cylinder 216 is an expanded portion 216B whose inner diameter is gradually increased, and the outer periphery of the main rubber 222 is bonded by vulcanization. An outer peripheral portion 224A of a support base 224 as a connecting member is provided on an inner peripheral portion of the main rubber 222.
Are vulcanized and adhered. In addition, a part of the main rubber 222 is extended to a part of the cylindrical part 216C of the outer cylinder 216 and a part of a lower end thereof, and is vulcanized and bonded. The support base 224 is a mounting portion for an engine (not shown), and mounting bolts 226 for fixing the engine are projected.

Here, the inner peripheral portion of the outer cylinder 216, the vibration absorbing main body 22
2 and the diaphragm 218 to form the liquid chamber 22.
8 are formed. The liquid chamber 228 is filled with a liquid 229 such as ethylene glycol.

An orifice member 230 is disposed in the liquid chamber 228 to divide the liquid chamber 228 into the main liquid chamber 232 and the first sub liquid chamber 23.
It is divided into four. The orifice member 230 is formed of a synthetic resin or the like and has a substantially hat-shaped cross section.

As shown in FIGS. 5 and 6, on the outer periphery of the orifice member 230, a narrow groove 244 having a rectangular cross section is formed along the circumferential direction. Outer cylinder 216 of this narrow groove 244
The side is closed by an extension of the main body rubber 222 to form a shake orifice 252. The shake orifice 252 has a rectangular opening 24 at one end in the longitudinal direction.
The other end is communicated with the first auxiliary liquid chamber 234 via the opening 244B.

The orifice member 230 has a rectangular hole 242 extending from the outer periphery toward the outer periphery on the opposite side, and the tip of the rectangular hole 242 communicates with the main liquid chamber 232 through the opening 242A. The orifice 246 is configured.

A boss 260 is fixed to the outer periphery of the cylindrical portion 216C of the outer cylinder 216 corresponding to the rectangular hole 242. The boss 260 has a concave portion 262 formed on the opposite side to the cylindrical portion 216 </ b> C, and the concave portion 262 is closed by a pressing plate 264. An annular recess 266 is formed at the opening of the recess 262.
The periphery of the diaphragm 268 is sandwiched between the pressing plate 66 and the holding plate 264. This diaphragm 268
In the free state, it projects in a substantially hemispherical shape toward the cylindrical portion 216 </ b> C, and a second sub liquid chamber 270 is provided between the diaphragm 268 and the concave portion 262. This second sub-wave chamber 27
0 and the rectangular hole 242 are communicated with the rectangular hole 242 via a through hole 272 penetrating the main rubber 222, the outer cylinder 216 and the boss 260.

An air chamber 274 is provided between the diaphragm 268 and the holding plate 264. The air chamber 274 is connected to the engine 76 (not shown) through the pipe 52 connected to the holding plate 264 in the same manner as in the reference example. It communicates with an intake manifold 70 (not shown).

[0049] Next will be described the operation of the embodiment.

In the vibration isolator 10 of this embodiment, the bottom plate 12 is fixed to a vehicle body (not shown) via mounting bolts 14, and the engine is mounted on a support 24 and fixed by mounting bolts 26.

When the vibration is a shake vibration (less than 15 Hz), the control means 60 energizes the solenoid valve 56. As a result, the inside of the air chamber 274 is brought into a negative pressure state, and the diaphragm 268 is pressed by the holding plate 26 as shown by an imaginary line in FIG.
4. Adhere to the inner wall surface of 4. As a result, the second sub liquid chamber 270 cannot be expanded or contracted, and the liquid 2 in the idle orifice 246 cannot be expanded or contracted.
29 flow disappears. Therefore, the liquid 229 moves back and forth between the main liquid chamber 232 and the first sub liquid chamber 234 only through the shake orifice 252. Absorbed.

When the vibration is idle vibration, the control means 60 does not energize the solenoid valve 56 and does not put the inside of the air chamber 274 into a negative pressure state. As a result, the diaphragm 268 expands toward the second sub-liquid chamber 270 to be in a free state (solid line state in FIG. 5), and the second sub-liquid chamber 270 can be expanded and contracted. Therefore, the liquid 229 passes through the idle orifice 246 and moves between the main liquid chamber 232 and the second sub liquid chamber 270,
The liquid 229 resonates in the liquid column in the idle orifice 242 to absorb the idle vibration.

In this embodiment, since the second auxiliary liquid chamber 270 and the air chamber 274 are provided outside the outer cylinder 216, there is no danger that the structure inside the outer cylinder 216 will be complicated.

In the embodiment, the piston 78 of the engine 76 is used as the negative pressure means. However, a device for specially sucking the air in the air chamber 43 may be provided separately.

Further, in the embodiments, the vibration damping device as the engine mount is shown, but the present invention is not limited to this, and it is needless to say that the present invention may be applied to a cabinet mount, a body mount and the like.

[0056]

As described above, the present invention has an excellent effect that vibrations over a wide frequency range can be effectively attenuated and absorbed, despite being a single vibration isolator.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of an anti-vibration device and an engine according to a reference example.

FIG. 2 is a cross-sectional view taken along the line II-II of the vibration isolator shown in FIG.

FIG. 3 is a view of the intermediate cylinder viewed from the arrow III in FIG. 4;

FIG. 4 is a partially exploded perspective view of a vibration isolator according to a reference example.

FIG. 5 is a cross-sectional view of the vibration isolator according to the embodiment of the present invention.

6 is a sectional view taken along line IX-IX of FIG. 5, showing the embodiment of the present invention.

[Explanation of symbols]

 10 Anti-vibration device 56 Solenoid valve (negative pressure means) 78 Piston (negative pressure means) 216 Outer cylinder (cylindrical member) 222 Body rubber (elastic body) 230 Orifice member (partition member) 224 Support base (connection member) 232 Main Liquid chamber 234 First sub liquid chamber 246 Idle orifice (second restricted passage) 252 Shake orifice (first restricted passage) 268 Diaphragm 270 Second sub liquid chamber 274 Air chamber

Continuation of the front page (56) References JP-A-4-277341 (JP, A) JP-A-60-220239 (JP, A) JP-A-6-1227537 (JP, A) JP-A-2-114237 (JP) , U)

Claims (1)

(57) [Claims] A cylindrical member connected to one of the vibration generating unit and the vibration receiving unit; a connecting member connected to the other of the vibration generating unit and the vibration receiving unit; and one opening of the cylindrical member closed. An elastic body that connects an outer peripheral portion to an opening end of the cylindrical member so as to connect the connecting member to a central portion and deforms when vibration occurs, and a main liquid that can expand and contract the elastic body as a part of a partition wall A first sub-liquid chamber that is isolated from the main liquid chamber; a partition member that separates the main liquid chamber from the first sub-liquid chamber; a main liquid chamber formed on the partition member; A first restriction passage communicating with the first auxiliary liquid chamber, a second eye control passage formed in the partition member and communicating with the main liquid chamber, and a second restriction passage provided in a part of the second restriction passage. A sub liquid chamber; a diaphragm constituting a partition of the second sub liquid chamber; and a second sub liquid chamber side of the diaphragm. Is arranged on the opposite side, the inside is the diaphragm is adhered to the inner wall side when it is at a negative pressure relative to atmospheric pressure substantially lost the second
An air chamber for preventing the flow of liquid in the second restricting passage by blocking the scaled sub-liquid chamber, and a negative pressure means for the interior of the air chamber to a negative pressure, the air chamber An anti-vibration device provided outside the tubular member .