JPH0979307A - Vibration insulating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the processing accuracy and to satisfy the surface roughness by parting a main liquid chamber from an auxiliary liquid chamber with a partition member made of a low moisture-absorbent material, and by forming a communication passage between the main liquid chamber and the auxiliary liquid chamber so that the communication passage is opened and closed by a valve element. SOLUTION: An outer cylinder 16 incorporates an intermediate cylinder and an intermediate block 24 made of a low moisture-absorbent material and serving as a partition member, a cut-out part 28A and the intermediate block 24 defining therebetween a main liquid chamber 30, and the intermediate block 24, a thin rubber layer 18 and a diaphragm 20 defining an auxiliary liquid chamber 32 surrounded thereby, and a communication passage 56 is formed between the main liquid chamber 30 and the auxiliary liquid chamber 56, and is adapted to be opened and closed by a rotor 36 which is a valve element inserted rotatably in a circular hole 34 and a cylindrical through-hole 35 and made of a low moisture-absorbent material. With this arrangement, it is possible to enhance the processing accuracy, to reduce the processing cost and to satisfy the surface roughness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolator for preventing transmission of vibration from a member that generates vibration, and is applicable to, for example, a case where transmission of vibration from an engine mounted on a vehicle is prevented. Things.

[0002]

2. Description of the Related Art For example, an anti-vibration device as an engine mount is arranged between an engine of a vehicle which is a vibration generating part and a vehicle body which is a vibration receiving part to prevent vibration generated by the engine. The vibration device absorbs the vibration and prevents the vibration from being transmitted to the vehicle body.

That is, as the vibration isolator, a pair of liquid chambers are provided inside the body of the vibration isolator, and a restriction passage serving as an orifice is formed in a partition member that partitions the pair of liquid chambers. It is known that the chambers communicate with each other. When the mounted engine operates to generate vibrations, the viscous resistance of the liquid in the orifices communicating with the liquid chambers absorbs the vibrations and blocks the transmission of the vibrations.

[0004]

On the other hand, a wide range of vibration frequencies are associated with a wide range of engine operating conditions. Therefore, in order to maintain anti-vibration characteristics even in vibrations of a wide range of frequencies, various lengths and 2. Description of the Related Art There is known a vibration isolator that forms a restriction passage having an inner diameter in a partition member and opens and closes the restriction passage with a valve based on a signal from a sensor to reduce vibration.

However, the partition member having the function of the valve body of the valve while partitioning the pair of liquid chambers and the valve element such as the rotor are always in contact with the liquid such as ethylene glycol in the liquid chamber. Therefore, when the partition member and the valve body are made of a normal resin material, they may be deformed and cracked due to moisture absorption, and the strength may be reduced. Therefore, the partition member and the valve body are manufactured by cutting an aluminum material or an iron material. . Therefore, there is a drawback that the processing accuracy is lowered due to burrs and the like generated by the cutting work and the processing cost is increased, and further, the processed surface has a poor roughness.

In consideration of the above facts, the present invention has a partitioning member and a valve body made of a low hygroscopic resin material having high machining accuracy, low machining cost, good surface roughness, and low hygroscopicity. The purpose is to provide a shaking device.

[0007]

According to a first aspect of the present invention, there is provided an anti-vibration device, in which an elastic body interposed between a vibration generating section and a vibration receiving section is filled with a liquid, and the elastic body is deformed to have an internal volume. Changes the main liquid chamber, a sub liquid chamber in which the liquid is sealed and at least a part of the inner wall is formed by a diaphragm, and the main liquid chamber and the sub liquid chamber are formed of a low hygroscopic resin material. A partition member that is partitioned and formed with a passage that communicates between the main liquid chamber and the sub liquid chamber and a partition member formed of a low hygroscopic resin material and connecting the main liquid chamber and the sub liquid chamber And a valve body that opens and closes the passage.

In the vibration isolator according to claim 2, the low hygroscopic resin material forming the partition member and the valve body is selected from the group consisting of poniphenylene sulfide, liquid crystal polymer, fluororesin, polybutylene terephthalate and thermoplastic polymer. It is characterized by being one of the materials.

The operation of the vibration isolator according to claim 1 will be described below. An elastic body is interposed between the vibration generator and the vibration receiver. The liquid is sealed in the main liquid chamber whose internal volume changes due to the deformation of the elastic body and the sub liquid chamber in which at least a part of the inner wall is constituted by the diaphragm. A partition member made of a low hygroscopic resin material partitions these liquid chambers, and a passage formed in the partition member communicates between the main liquid chamber and the sub liquid chamber. Further, the valve body formed of the low hygroscopic resin material operates to open and close the passage that connects the main liquid chamber and the sub liquid chamber.

Therefore, when the vibration is transmitted from the vibration generating portion side, the elastic body is deformed, the deformation of the elastic body attenuates the vibration, and it becomes difficult to transmit the vibration to the vibration receiving portion side. In addition, the internal volume of the main liquid chamber changes with the deformation of the elastic body, and the pressure changes to the liquid in the passage that is opened and closed and switched by the valve body according to the frequency of the vibration from the vibration generator side. Occurs, and the diaphragm on the side of the sub liquid chamber, which communicates with the main liquid chamber through the passage, is deformed.

As a result, the vibration is damped not only by the elastic body but also by the liquid, and it becomes more difficult to transmit the vibration to the vibration receiving portion side.

On the other hand, since the partition member and the valve body are made of a low hygroscopic resin material, even if the liquid in the liquid chamber comes into contact with the partition member and the valve body, it becomes difficult to absorb moisture, resulting in deformation and cracking. Difficulty and less reduction in strength. In addition, instead of cutting aluminum and iron materials to produce partition members and valve bodies, there is no burr and high machining accuracy due to the production of these partition members and valve bodies with low hygroscopic resin materials. In addition, it is possible to obtain a resin partition member and a valve body that have a low processing cost and good surface roughness.

For example, when the partition member and the valve body are molded by injection molding, the surface roughness becomes 6S or less, which is very smooth.

The operation of the vibration isolator according to claim 2 will be described below. The present invention has the same function as the first embodiment. However, the low hygroscopic resin material forming the partition member and the valve body,
Poniphenylene sulfide (PPS), liquid crystal polymer,
Since the material is any one of fluororesin, polybutylene terephthalate (PBT), and thermoplastic polymer, the hygroscopicity of the partition member and the valve body can be more reliably lowered.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a vibration isolator according to the present invention is shown in FIGS. 1 to 3, and this embodiment will be described based on these drawings.

As shown in FIGS. 1 and 2, the so-called bush type vibration damping device 10 is provided with a mounting frame 12 for connection to a vehicle body (not shown), and inside the annular portion 14 of the mounting frame 12. A cylindrical outer cylinder 16 that serves as a first mounting member is disposed in the. A thin rubber layer 18 is vulcanized and adhered to the inner peripheral surface of the outer cylinder 16, and a part of the thin rubber layer 18 serves as a diaphragm 20 separated from the inner peripheral surface of the outer cylinder 16. As shown in FIG. 1, an air chamber 31 is provided between the diaphragm 20 and the outer cylinder 16 and communicates with the outside as needed.

As shown in FIG. 2, an intermediate cylinder 22 and an intermediate block 24 made of a low hygroscopic resin material, which is a partition member and functions as a bearing, are inserted into the outer cylinder 16. Become. The intermediate block 24 has a substantially semicircular block shape when viewed from the axial direction of the outer cylinder 16, and has an outer peripheral surface in close contact with the inner peripheral surface of the thin rubber layer 18 as shown in FIG. 1. The intermediate block 24 constitutes a pair of on-off valves with a rotor 36 described later. As shown in FIG. 2, flange portions 22A are formed at both axial ends of the intermediate cylinder 22, and the intermediate block 24 is fitted between the pair of flange portions 22A. In addition, the outer peripheral surface of the flange portion 22A has a thin rubber layer 18
It is closely attached to the inner surface of the.

As shown in FIG. 1, a cutout portion 22B is formed in the intermediate cylinder 22 so as to face the central portion of the intermediate block 24 on the plane portion 24B side, and the inside of the cutout portion 22B is connected to an engine (not shown). The inner cylinder 26, which serves as a second mounting member, penetrates through. The inner cylinder 26 is disposed coaxially with the outer cylinder 16 and is formed of a rubber material or the like between the inner cylinder 26 and the intermediate cylinder 22.
8 has been passed over. As a result, the inner cylinder 26 becomes the outer cylinder 1
It is possible to move relative to 6.

The elastic body 28 is the flange portion 22 of the intermediate cylinder 22.
It is also extended to the outer peripheral surface between A and a part thereof is in close contact with the inner peripheral arc surface 24A of the intermediate block 24. Further, a cutout 28A is provided in the middle of the elastic body 28 and below the inner cylinder 26.
Is formed, and the main liquid chamber 30 is formed between the cutout portion 28A and the intermediate block 24.

On the other hand, a sub liquid chamber 32 surrounded by the intermediate block 24, the thin rubber layer 18 and the diaphragm 20 is formed between the flange portions 22A of the intermediate cylinder 22.
That is, the liquid chambers 30, 32 are formed by the outer cylinder 16, the intermediate cylinder 22, the elastic body 28, and the grooved rubber layer 18 interposed therebetween.
The inner wall surface for partitioning the
4 divides the liquid chambers 30 and 32 in two. Then, the main liquid chamber 30 and the sub liquid chamber 32 are sealed so as to be filled with a liquid such as ethylene glycol.

A circular hole 34 is formed on the plane portion 24B side of the intermediate block 24, and the circular hole 3 is formed on the bottom surface of the circular hole 34.
The outer cylinder 1 of the intermediate block 24 is made smaller in diameter than 4
A circular through hole 35 penetrating the outer peripheral surface on the sixth side is formed coaxially with the circular hole 34. Further, on the outer cylinder 16 side of the intermediate block 24, a counterbore portion 39 as an engaging portion is provided coaxially with the circular through hole 35, and further, an O-ring 41 for sealing is provided outside the counterbore portion 39. Is fitted.

A rotor 36 made of a low hygroscopic resin material, which is a valve body, is rotatably inserted into the circular hole 34 and the circular through hole 35. A cylindrical portion 36A having a cylindrical shape is formed on the main liquid chamber 30 side of the rotor 36, and a thin shaft portion 38 as a rotating shaft is integrally provided on the side opposite to the cylindrical portion 36A. A circular hole 34 is provided on the flat portion 24B side of the intermediate block 24.
An annular recess 24C is formed coaxially with the annular recess 24C, and the annular washer 40 is screwed to the annular recess 24C to prevent the rotor 36 from slipping out.

A pair of thin grooves 42 are continuously formed on the outer periphery of the thin shaft portion 38, and an O-ring 44 is formed in the thin grooves 42.
Are fitted respectively. Therefore, this O-ring 4
The liquid does not leak to the outside of the intermediate block 24 through the circular through hole 35 due to 4.

Further, the cylindrical portion 36A is formed with a pair of through holes 46 which communicate the inside and outside of the cylindrical portion 36A. On the other hand, a passage 56 is formed in the intermediate block 24 along the radial direction of the circular hole 34, and one end of the passage 56 has a circular hole 3
4 is opened on the inner circumference. The other end of the passage 56 is in communication with one end of a passage 58 which is a groove formed in the outer circumference of the intermediate block 24 along the circumferential direction, and the other end of the passage 58 is in communication with the sub liquid chamber 32. In addition, these passages 5
Reference numerals 6 and 58 serve as idle orifices 60 as limiting passages for absorbing idle vibration.

Therefore, when the rotor 36 is rotated and the through hole 46 of the cylindrical portion 36A faces the passage 56, the main liquid chamber 30 and the sub liquid chamber 32 communicate with each other through the idle orifice 60, and from this position. If the rotor 36 is rotated 90 ° and the through hole 46 of the cylindrical portion 36A does not face the passage 56, the main liquid chamber 30 and the sub liquid chamber 32 are not communicated by the idle orifice 60. That is, the rotor 36 opens and closes the orifice 60.

Further, as shown in FIG. 3, the intermediate block 2
A passage 64, which is a groove portion, is formed on the outer peripheral surface of No. 4. One end of this passage 64 is connected to the passage 5 of the intermediate block 24.
It is connected to the sub liquid chamber 32 by opening at the end 24D on the eighth side. The middle portion of the passage 64 is bent in a U shape near the end portion 24G on the side opposite to the passage 58 side, and the other end of the passage 64 is formed through the through hole 6 formed in the middle block 24.
It communicates with the main liquid chamber 30 via 5. The passage 64 and the through hole 65 serve as a shake orifice 62 as a restriction passage for absorbing shake vibration.

On the other hand, as shown in FIG. 1, a circular hole 66 having a diameter larger than that of the circular through hole 35 is provided at a position corresponding to the circular through hole 35 of the outer cylinder 16 and the thin rubber layer 18. Further, a large diameter circular hole 68 having a diameter larger than that of the circular hole 66 of the outer cylinder 16 is provided at a position corresponding to the circular through hole 35 of the intermediate block 24 of the annular portion 14.

On the outside of the annular portion 14, a motor 70 as an actuator is arranged at a position corresponding to the large diameter circular hole 68. The case 72 of the motor 70 has a flange portion 7
4 is provided, and the flange portion 74 is formed in an arc shape along the outer diameter of the annular portion 14 of the mounting frame 12. The flange 74 has a pair of mounting holes 76 (see FIG.
(Only one of which is shown in the figure) is provided, and a screw 78 inserted through these mounting holes 76 is screwed into a screw portion (not shown) provided in the annular portion 14,
The motor 70 is fixed to the annular portion 14. The diameter of the mounting hole 76 is slightly larger than the outer diameter of the screw portion of the screw 78, and the motor 70 can adjust its position slightly in the axial direction and the circumferential direction of the annular portion 14.

The tip of the rotary shaft 71 of the motor 70 is formed in a rectangular cross section (see FIG. 3), and the rotor 36 is inserted through the large-diameter circular hole 68 of the annular portion 14 and the circular hole 66 of the outer cylinder 16. Connection hole 38 having a rectangular cross section formed on the tip side of the thin shaft portion 38.
A (see FIG. 3) is inserted.

Further, the case 72 of the motor 70 is provided with a boss 82 as an engaging portion coaxially with the rotating shaft 71. The outer diameter of the boss 82 is smaller than the inner diameter of the counterbore portion 39 by a predetermined dimension, so that the boss 82 and the counterbore portion 39
And are tightly fitted together. Therefore, the boss 82
The above-mentioned intermediate block 24 is fitted into the spot facing portion 39 without any play.

From the above, the arrangement in which the rotor 36 does not communicate between the main liquid chamber 30 and the sub liquid chamber 32 and the main liquid chamber 30 and the sub liquid chamber 3 via the idle orifice 60 as shown in FIG.
It is rotated by a motor 70 so as to selectively adopt an arrangement in which the two communicate with each other.

The motor 70 is connected to a control circuit 48 which is a control means, and its rotation is controlled by the control circuit 48. The control circuit 48 is driven by the vehicle power supply, receives the detection signals from at least the vehicle speed sensor 50 and the engine speed detection sensor 52, detects the vehicle speed and the engine speed, and can determine whether idle vibration or shake vibration occurs. It is like this.

Next, the assembly sequence of the vibration isolator 10 according to this embodiment will be described. First, the intermediate block 24 and the rotor 36 made of a low hygroscopic resin material are manufactured by injection molding. Then, the rotor 36 to which the O-ring 44 is attached is inserted into the circular hole 34 of the intermediate block 24, and the annular washer 4
Screw 0. This intermediate block 24 is replaced with the intermediate cylinder 22.
Then, the intermediate cylinder 22 and the intermediate block 24 are inserted into the outer cylinder 16 in the liquid.

Next, the circular hole 66 of the outer cylinder 16 and the circular through hole 35 of the intermediate block 24 are aligned, the outer cylinder 16 is reduced in diameter by a predetermined amount, and the outer cylinder 16 and the intermediate block 24 are fitted together. At the same time, by crimping both ends of the outer cylinder 16, the intermediate block 24
And, the intermediate cylinder 22 is fixed. As a result, the thin rubber layer 18 is provided on the outer peripheral surface 24E of the intermediate block 24 and the intermediate cylinder 22.
Is closely attached to the outer peripheral surface of the to seal the inside. After the outer cylinder 16 is reduced in diameter, the intermediate block 24 and the thin rubber layer 18 come into close contact with each other due to the elasticity of the thin rubber layer 18, and the outer cylinder 16 is not sufficiently reduced in diameter. Alternatively, even if the dimensional accuracy of the inner peripheral surface shape of the outer cylinder 16 or the outer peripheral surface shape of the intermediate block 24 is somewhat poor, leakage of the liquid from the passages 58 and 64 is prevented.

Then, the direction of the circular hole 66 of the outer cylinder 16 is aligned with the large diameter circular hole 68 of the annular portion 14 of the mounting frame 12, and the outer cylinder 16 is press-fitted into the annular portion 14. Then, the rotating shaft 71 of the motor 70 is fitted into the connecting hole 38A of the rotor 36, and the motor 70 is screwed to the annular portion 14.

The boss 82, which is provided coaxially with the axis of the rotary shaft 71 of the motor 70, is fitted into the counterbore 39 which is provided coaxially with the axis of the rotor 36. When the is fitted into the connecting hole 38A of the rotor 36, the axis of the rotor 36 and the axis of the rotating shaft 71 of the motor 70 are exactly aligned. Therefore, the rotor 36 and the rotary shaft 71 can smoothly rotate after the assembly, and operate reliably.

Next, the operation of the present embodiment will be described. When the engine mounted on the inner cylinder 26 operates, the vibration of the engine is transmitted to the elastic body 28 via the inner cylinder 26. The elastic body 28 acts as a vibration absorbing body, and can absorb the vibration by the vibration damping function based on the internal friction of the elastic body 28.
Further, the liquids in the main liquid chamber 30 and the sub liquid chamber 32, whose inner volumes change with the deformation of the elastic body 28 and the diaphragm 20, flow through each other through the orifices 60 and 62.

Then, as a result of providing the rotor 36 in the circular hole 34 to which the ends of the orifice 60 are connected, the following effects are obtained.

When the 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 circuit 48 uses the vehicle speed sensor 50 and the engine speed detection sensor 52 to determine whether or not shake vibration is occurring. When the control circuit 48 determines that the shake vibration is occurring,
The control circuit 48 actuates the motor 70 to rotate the rotor 36 so that the through hole 46 is arranged so as not to correspond to the passage 56.
This closes one end of the passage 56. As a result,
The idle orifice 60 is closed, and the pressure change generated in the main liquid chamber 30 based on the engine vibration is transmitted to the liquid in the shake orifice 62, and the shake vibration is absorbed by the resistance of the liquid.

When the engine is idling or the vehicle speed is 5 km / h or less, idle vibration (20 to
40 Hz). At this time, since the shake orifice 62 having a small cross-sectional area, a long length, and a large passage resistance vibrates at a high frequency, it is clogged.

The control circuit 48 uses the vehicle speed sensor 50,
The engine speed detection sensor 52 determines whether or not idle vibration is occurring. When the control circuit 48 determines that the idle vibration is occurring, the control circuit 48 rotates the motor 70 to bring the through hole 46 of the rotor 36 into the position corresponding to the passage 56. As a result, the liquid passes through the idle orifice 60 having a small passage resistance and the main liquid chamber 30 and the sub liquid chamber 32.
The liquid column resonates in the idle orifice 60, the dynamic spring constant is reduced, and the vibration is absorbed.

As described above, the orifices 60 and 62 can reduce shake vibration and idle vibration, respectively.

On the other hand, since the intermediate block 24 and the rotor 36 are respectively made of a low hygroscopic resin material, even if the liquid in the liquid chambers 30, 32 comes into contact with the intermediate block 24 and the rotor 36, it is difficult to absorb moisture. Therefore, deformation and cracks are less likely to occur, and the reduction in strength is reduced. That is, by forming the intermediate block 24 and the rotor 36, each of which has a thin portion, from a low hygroscopic resin material, the intermediate block 24 and the rotor 36 of the intermediate block 24 and the rotor 36 are heated even in a liquid such as ethylene glycol which becomes hot with the operation of the engine. Deformation and cracks are less likely to occur in the thin-walled portion, and the reduction in strength is reduced, so that the optimum intermediate block 24 and rotor 36 can be obtained.

In place of manufacturing the intermediate block 24 and the rotor 36 by cutting an aluminum material or an iron material, burrs are generated as the intermediate block 24 and the rotor 36 are manufactured with a low hygroscopic resin material. Since there is no deburring treatment, the processing accuracy is high, the processing cost is low, and the surface roughness is good.
4 and the rotor 36 can be obtained.

That is, the intermediate block 24 is formed by injection molding.
Since the rotor 36 is molded, the surface roughness is 6S.
It becomes the following and becomes very smooth. Therefore, the surfaces of the intermediate block 24 and the rotor 36 that slide with each other are smoothed, and the movement of the rotor 36 in the intermediate block 24 is smooth.

On the other hand, as the low hygroscopic resin material forming the intermediate block 24 and the rotor 36, any one of ponyphenylene sulfide (PPS), liquid crystal polymer, fluororesin, polybutylene terephthalate (PBT) or thermoplastic polymer is used. The material of can be adopted. Therefore, by using such a material, the hygroscopicity of the intermediate block 24 and the rotor 36 can be lowered more reliably.

Further, as the thermoplastic polymer in this,
Polyamide MXD6, which is a heat-resistant polyamide resin
(Trade name of Mitsubishi Gas Chemical Company: Lenny) is known.
This polyamide MXD6 has a low water absorption rate (5.8% under the condition of being saturated in 20 ° C. water, 3.1% under the condition of 65% RH equilibrium), and has a high tensile strength of 1010 kg / cm ² .
It is optimal as a resin material for the intermediate block 24 and the rotor 36, which is required to have low hygroscopicity and high rigidity (high strength) even at high temperatures.

In the above embodiment, the outer cylinder 1 is attached to the vehicle body.
Although the 6 side is attached and the inner cylinder 26 side is attached to the engine, the configuration may be reversed. Although the elastic body 28 is made of rubber, other well-known elastic materials may be used.

On the other hand, in the above embodiment, the purpose of the present invention is to prevent the vibration of the engine mounted on the vehicle. However, it goes without saying that the anti-vibration device of the present invention can be used for other purposes.
Further, the shape and the like are not limited to those of the embodiment.

On the other hand, although the rotor is rotated by the motor in the above embodiments, the present invention is not limited to this, and the actuator for rotating the rotor may be other than the motor, and the valve body and the rotor are also different. A valve other than the above may be used.

[0051]

As a result of the constitution described above, the present invention is a partition made of a low hygroscopic resin material having high machining accuracy, low machining cost, good surface roughness, and low hygroscopicity. It has become possible to obtain a vibration isolation device having a member and a valve body.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a vibration damping device according to the present invention.

FIG. 2 is a perspective view showing an exploded state of an embodiment of the vibration damping device according to the present invention.

FIG. 3 is a perspective view showing a rotor, an intermediate block, and the periphery of a motor (excluding an outer cylinder and a mounting frame) applied to an embodiment of a vibration isolator according to the present invention.

[Explanation of symbols]

 10 Vibration Isolator 16 Outer Cylinder 20 Diaphragm 24 Intermediate Block 26 Inner Cylinder 28 Elastic Body 30 Main Liquid Chamber 32 Sub-Liquid Chamber 36 Rotor 60 Idle Orifice 62 Shake Orifice

Claims (2)

[Claims] 1. An elastic body interposed between a vibration generating section and a vibration receiving section, a liquid is sealed, and a main liquid chamber whose internal volume is changed by deformation of the elastic body, and a liquid are sealed. Together with the sub-liquid chamber, at least a part of the inner wall of which is formed by the diaphragm, and the main liquid chamber and the sub-liquid chamber which are formed of a low hygroscopic resin material and partition the main liquid chamber and the sub-liquid chamber, A partition member having a passage communicating with the main liquid chamber and a valve member formed of a low hygroscopic resin material for opening and closing the passage communicating with the main liquid chamber and the sub liquid chamber. Anti-vibration device characterized. 2. The low hygroscopic resin material forming the partition member and the valve body is any one of ponyphenylene sulfide, liquid crystal polymer, fluororesin, polybutylene terephthalate, and thermoplastic polymer. The anti-vibration device according to claim 1, wherein