JPH08145112A - Engine mount - Google Patents

Abstract

PURPOSE: To provide an engine mount which shuts off engine vibrations to be transmitted to a car body in good performance and allows easy air bleeding operation at the time of installation. CONSTITUTION: A main liquid chamber 51 is separated from an aux. liquid chamber 52 by a partition plate 53. A spherical recess 53b is formed in the partition plate 53 on its aux. liquid chamber 52 side, and the space which the recess 53b constitutes is in communication with the main liquid chamber 51 through an air bleeder hole 53c furnished in the partition plate 51. When an engine mount 30 divided in two by the partition plate 53 is installed in a non- compressive liquid, the air in the air aux. liquid chamber 52 can be bleed not only through a gap S but also through the bleeding hole 53c. This permits preventing air from flowing into the main liquid chamber 51 which has been installed in place, so that engine vibrations can be damped in good performance by means of proper change of the liquid pressure in the main liquid chamber 51 driven by vibration of a voice coil 70.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine mount disposed between a vehicle body and an engine, which is a power unit, for damping engine vibration, and more particularly to a hydraulically controlled electronically controlled engine mount.

[0002]

2. Description of the Related Art Recently, in order to improve the performance of a vehicle, it is desired to reduce the engine vibration transmitted to passengers in the vehicle by attenuating the engine vibration during running and idle operation. In response to such demands, engine vibration is being satisfactorily damped by electronically controlling the damping characteristics of the engine mount. For example, a main liquid chamber and a sub liquid chamber communicating with the main liquid chamber are provided below the engine support portion of the engine mount, and periodic hydraulic pressure vibration is generated in the main liquid chamber by an actuator outside the main liquid chamber. Therefore, the hydraulic pressure control type engine mount that controls the phase difference between the hydraulic pressure vibration and the engine side vibration connected to the engine mount is an effective means for suppressing the transmission of the engine vibration to the vehicle body. It is considered.

[0003]

In such a conventional hydraulic control type engine mount, for example, a main liquid chamber and a sub liquid chamber are assembled by assembling a support assembly on the engine side and an actuator assembly on the vehicle body in a liquid. Air is kept out of the liquid chamber. However, in this type of engine mount, the main fluid chamber and the secondary fluid chamber communicate with each other only through a small gap, so when installing the engine mount assembly divided by the partition wall, the main fluid chamber or the secondary fluid chamber It is difficult to evacuate the room. If the main liquid chamber is assembled with air mixed therein, the pressure of the main liquid chamber that changes in volume in accordance with the drive from the actuator does not appropriately change according to the engine vibration, so that the damping characteristic of the engine mount deteriorates. Further, the air mixed in the sub liquid chamber may eventually flow into the main liquid chamber, so that the damping characteristic of the engine mount is deteriorated.

The present invention has been made in order to solve such problems, and provides an engine mount which can satisfactorily block the transmission of engine vibration to the vehicle body and which can easily remove air during assembly. The purpose is to provide.

[0005]

An engine mount according to claim 1 of the present invention for solving the above-mentioned problems is an engine mount which is arranged between a vehicle body and a power unit and which damps vibrations of the power unit. The partition between the main liquid chamber whose volume is changeable and the sub liquid chamber whose volume is changeable which is provided adjacent to this main liquid chamber in the axial direction, and the main liquid chamber in which an incompressible fluid is sealed and the above A partition wall having a communication hole that communicates with the sub-liquid chamber in the central portion and an air vent hole that penetrates the partition wall, and an inner peripheral wall of the partition wall that fits into the communication hole and forms the communication hole And a movable member that adjusts the pressure in the main liquid chamber by changing the volume of the main liquid chamber by axially reciprocating in the communication hole by forming a gap in the radial direction, and reciprocating the movable member. Driving means for moving and the driving hand A control device for controlling the above, and an air chamber opened to the atmosphere adjacent to the sub liquid chamber and axially opposite to the main liquid chamber, and the sub liquid chamber are liquid-tightly partitioned, and reciprocates together with the movable member. It is characterized in that it has a moving elastic diaphragm, and can be divided and assembled with the partition as a boundary.

An engine mount according to a second aspect of the present invention is the engine mount according to the first aspect, wherein a recess is provided on the side of the sub-liquid chamber of the partition wall, and the main liquid chamber side of the partition wall faces upward. The air vent hole is formed at an upper position of the recess. Claim 3 of the present invention
The engine mount described in the above is characterized in that the air vent hole is closed when the assembly of the engine mount in claim 1 is completed.

[0007]

According to the engine mount of the first aspect of the present invention, the partition wall is provided with an air vent hole penetrating the main liquid chamber and the sub liquid chamber, and the air is enclosed in the main liquid chamber and the sub liquid chamber. When assembling an assembly of engine mounts divided by a partition wall in an incompressible liquid, air in the main liquid chamber or the sub liquid chamber can be discharged through the air vent hole. Therefore, almost no air is mixed into the main liquid chamber and the sub liquid chamber after assembly,
The pressure of the main liquid chamber, the volume of which fluctuates due to the reciprocating movement of the movable member, is adjusted according to the control of the controller so that the engine vibration is damped well.

According to the engine mount of the second aspect of the present invention, the recess is provided on the sub-liquid chamber side of the partition wall, and the main liquid chamber side of the partition wall is on the upper side, similar to the vertical relationship when the engine mount is installed in the vehicle. At this time, an air vent hole penetrating the partition wall is formed at a position above the recess. For this reason, when the assembly of the engine mount divided by the partition wall is assembled in the incompressible liquid, the assembly direction can be easily discriminated. Therefore, the engine can be easily discharged while the air in the sub liquid chamber is discharged from the air vent hole. Mounts can be assembled.

According to the engine mount of the third aspect of the present invention, the air vent hole provided in the partition wall is closed in a state where the engine mount is completely assembled. Since the diameter of the air vent hole can be set large, when assembling the engine mount assembly divided by the partition wall in an incompressible liquid,
It becomes easier to discharge the air in the main liquid chamber or the sub liquid chamber.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 3 shows a state in which an engine mount according to a first embodiment of the present invention is mounted on a vehicle. The engine mount 30 is a hydraulic control type electronically controlled engine mount, and is arranged between the stay 10a of the vehicle body 10 and the stay 20a of the engine 20 which is a power unit.
An electronic control unit (hereinafter referred to as “ECU”) 100 that controls the engine mount 30 inputs a rotation angle signal Ne related to the rotation speed of the engine 20 from a rotation angle sensor 22 provided in a distributor 21 of the engine 20. The operation of the engine mount 30 is controlled by inputting a reference position signal G2 indicating the reference position of the crank angle from a reference position sensor 23 also provided in the distributor 21. The rotation angle sensor 22 and the reference position sensor 23 are a kind of magnet pickup.

As shown in FIG. 1, the engine mount 30
Is used with the lower end fastened to the vehicle body 10 side and the upper end fastened to the engine 20 side with bolts. The engine mount 30 includes a support portion 40 that is provided on the engine 20 side and supports the engine 20, a vibration damping portion 50 that damps the vibration of the engine 20, and an actuator portion 60 that is a driving unit that drives the vibration damping portion 50.

The support portion 40 comprises a frame 41, a mount rubber 42, a boss 43, a stopper 44, a stopper 45 and a stopper 46. The frame 41 is fixed on the opening edge 61 a of the outer yoke 61 of the actuator portion 60 by fastening a diaphragm 55, which is an elastic diaphragm formed in a disk shape of the vibration damping portion 50, and a partition plate 53 together with bolts 66. . An annular frame 41, a dome-shaped mount rubber 42, and a cylindrical boss 43 are disposed on the partition plate 53. The partition plate 53 is previously fixed to the opening edge 61a by a plurality of screws 67.

A stopper 44 fastened and fixed to the frame 41 by bolts 47 is arranged on the boss 43. The stoppers 45 and 46 are arranged on the boss 43 in a circumferential direction determined by a positioning pin 48 and fastened together with the boss 43 by a bolt (not shown). A rubber cushioning material is baked on the contact surfaces of the stoppers 45 and 46 as stoppers. The stoppers 44, 45, and 46 operate so as to regulate the excessive displacement of the support portion 40.

The vibration damping portion 50 is provided between the support portion 40 and the actuator portion 60, and the main liquid chamber 51 and the sub liquid chamber 52 are axially arranged in this order immediately below the mount rubber 42, and the partition wall is formed. It is partitioned by a partition plate 53 which is. The sub liquid chamber 52 and the air chamber 54 formed on the vehicle body 10 side of the sub liquid chamber 52 are liquid-tightly partitioned by a diaphragm 55. An incompressible fluid is sealed in the main liquid chamber 51 and the sub liquid chamber 52. Since the air chamber 54 is open to the atmosphere, the sub liquid chamber 52 is in equilibrium with the atmospheric pressure.

A circular communication hole 53a is formed in the center of the partition plate 53.
Is formed, and the main liquid chamber 51 and the sub liquid chamber 52 communicate with each other through the communication hole 53a. A single hemispherical recess 53b is formed on the side of the partition plate 53 on the side of the secondary liquid chamber 52.
The space formed by b and the main liquid chamber 51 communicate with each other through an air vent hole 53c provided in the partition plate 51 and having a diameter of 1 mm. The apex of the concave portion 53b on the main liquid chamber 51 side is located on the main liquid chamber 51 side of the collar 56a of the movable member 56 described later. The movable member 56 is formed in a bottomed cylindrical shape that opens upward, and is disposed in a horizontal posture in the communication hole 53a. A collar 56a is formed on the upper edge of the movable member 56.
A gap S of about 0.1 to 0.3 mm is formed between the outer wall of the partition plate and the inner wall of the partition plate 53 forming the communication hole 53a.
A mounting portion 56b is provided at the center of the lower surface of the movable member 56 so as to project. The mounting portion 56b and the spool 7 of the yoke 74
The central portion of the diaphragm 55 is sandwiched between the diaphragm 4 and 4a, and they are connected to each other by bolts 57.

A lower yoke 71 is fixed to the bottom of the outer yoke 61 by a plurality of screws 65 and a positioning pin 64, and a cylindrical portion 71a is integrally formed on the upper surface of the lower yoke 71. An annular ferrite magnet 72 is attached on the lower yoke 71 so as to surround the cylindrical portion 71a, and an annular upper yoke 73 is attached on the ferrite magnet 72. The inner peripheral wall of the upper yoke 73 faces the outer peripheral wall of the cylindrical portion 71 a of the lower yoke 71 with a predetermined gap. Upper yoke 73
A damper holder 62 is adhered on the upper side in a positioned state, and two dampers 63 made of non-woven fabric, which are supporting members, are stretched around the inner circumference of the damper holder 62 at a predetermined interval vertically and open downward. The bottom cylindrical yoke 74 is supported. The yoke 74 is composed of a spool 74a forming an upper surface and an aluminum foil bobbin 74b which is wound around the circumference of the spool 74a and adhered thereto. Both dampers 63 have a bellows-shaped cross section and restrict the movement of the yoke 74 in the direction orthogonal to the axial direction, while permitting the yoke 74 to slightly move in both directions of the axis. The moving coil 75 is a lower yoke 7.
It is inserted between the outer peripheral wall of the first cylindrical portion 71 a and the inner peripheral wall of the upper yoke 73, and is wound around the lower outer periphery of the yoke 74. The movable coil 75 is made of a magnetic material such as the lower yoke 7.
1 and the upper yoke 73 are both kept at a predetermined distance.

The lower yoke 71, the ferrite magnet 72, the upper yoke 73, the yoke 74, and the movable coil 75 include a so-called voice coil 70 as an actuator.
Is configured. Lower yoke 71, ferrite magnet 7
When an alternating current is supplied from the connector 80 to the movable coil 75 in the DC magnetic field formed by the upper coil 73 and the upper yoke 73, the movable coil 75 vibrates in the axial direction according to Fleming's left-hand rule, and the yoke 74 also moves.
Vibrates with.

Next, a method of assembling the engine mount 30 will be described with reference to FIG. The engine mount 30
A non-compressible liquid that is assembled in advance in the support assembly 101 including the support 40 and the actuator assembly 102 including the vibration damping unit 50 and the actuator 60, and is sealed in the main liquid chamber 51 and the sub liquid chamber 52. The support assembly 101 and the actuator assembly 102 are assembled in a liquid of ethylene glycol (LLC). At this time, the air chamber 54 is sealed so that the incompressible liquid does not flow in. Since the main liquid chamber 51 is formed in the liquid by assembling the support portion assembly 101 and the actuator assembly 102, air does not enter the main liquid chamber 51. On the other hand, the sub-liquid chamber 52 has a diaphragm 55.
Since it is liquid-tightly sealed with the air chamber 54 and the gap S is as small as about 0.1 to 0.3 mm as described above, it is difficult to discharge the air in the sub liquid chamber 52 as it is. When the support portion assembly 101 and the actuator assembly 102 are assembled while the sub liquid chamber 52 is mixed with the air, the air in the sub liquid chamber 52 is discharged through the gap S or the air vent hole 53c.
There is a risk that it may flow into the main chamber 1 and prevent an appropriate pressure change in the main liquid chamber 51. Therefore, when the movable member 56 is pressed downward with a finger with the partition plate 53 side of the actuator assembly 102 facing upward before being assembled to the support portion assembly 101, the air in the sub liquid chamber 52 is discharged from the gap S. In addition, the air accumulated in the space formed in the recess 53b located above the collar 56a is also discharged to the outside of the sub liquid chamber 52 through the air vent hole 53c. When the air has sufficiently escaped from the sub liquid chamber 52, the support portion assembly 101 and the actuator assembly 102 are tightened with bolts 66 to be assembled.

Next, the operation of the engine mount 30 when the sub liquid chamber 52 is normal without air and when the air is mixed will be described with reference to FIGS. 4A and 4B, respectively. . In (A) and (B) of FIG.
Voice coil 70 according to engine amplitude and engine amplitude
The input voltage applied to the movable coil 75 and the pressure in the main liquid chamber 51 that fluctuates due to the vibration of the movable member 56 due to this input voltage are shown in each figure. The amplitude a of the engine vibration is 0.1 mm, the potential difference b of the AC voltage input to the voice coil 70 is 10 V, and the voice coil 7
The vibration frequency of 0 is 150 Hz, (A) and (B) of FIG.
The vertical axis represents pressure and the scale is 20 kPa, and the horizontal axis represents time and the scale is 0.2 ms.

(1) Normal state As shown in FIG. 4A, when an AC voltage corresponding to engine vibration is applied from the ECU 100 to the movable coil 75,
The movable member 56 vibrates in the axial direction within the communication hole 53a together with the yoke 74. Outer peripheral wall of movable member 56 and communication hole 53a
Since the gap S between the partition plate 53 and the inner peripheral wall of the partition plate 53 is made as narrow as possible while avoiding contact between the two members when the movable member 56 vibrates, the operating frequency of the voice coil 70 is 10 to 200 Hz. Within the range, the movable member 56 vibrates in the axial direction and the volume of the main liquid chamber 51 changes. Then, a pressure amplitude is generated in the main liquid chamber 51 due to the resistance of the incompressible liquid that slightly flows between the main liquid chamber 51 and the sub liquid chamber 52 through the gap S, and this pressure amplitude attenuates the engine vibration. Changes to. At this time, the main liquid chamber 51 and the sub liquid chamber 52
Since the non-compressible liquid sealed in the liquid only slightly flows through the gap S between the main liquid chamber 51 and the sub liquid chamber 52 due to its viscous action even at a low frequency of about 10 Hz, the main liquid chamber 5
It is possible to generate a sufficient pressure difference between 1 and the sub liquid chamber 52.

When the movable member 56 vibrates to change the volume of the main liquid chamber 51, the air bleed hole 53c acts as an orifice to cause a resonance phenomenon. Depending on the vibration frequency of the voice coil 70, a desired damping effect can be obtained. It is conceivable that the effect of lowering the pressure will affect the pressure change in the main liquid chamber 51. However, the resonance phenomenon is determined by the diameter of the air vent hole 53c, which is an orifice, and the flow path length. With the air vent hole 53c having a diameter of 1 mm in this embodiment, if the flow path length is set to 1 mm or more. Since the resonance frequency is 5 Hz or less, there is no effect of reducing the damping effect in the actual use range of the engine mount 30 of 10 to 200 Hz. Further, since the amplitude or phase of the hydraulic pressure in the main liquid chamber 51 can be arbitrarily controlled by changing the phase, voltage or frequency of the input voltage applied to the movable coil 75, the damping characteristic of the engine mount 30 can be easily changed. it can.

(2) When Air is Mixed On the other hand, when the engine mount 30 is assembled with the sub liquid chamber 52 containing air, as shown in FIG.
When the same AC voltage as that in the normal state is applied to the moving coil 75,
When the pressure of the main liquid chamber 51 rises, the mixed air is compressed and becomes minute. At this time, the liquid surrounding the mixed air collides due to its inertial force, that is, a so-called water hammer action, so that the main liquid chamber 51
Since the pressure fluctuation difference in the inside increases and the pressure sine wave in the main liquid chamber 51 is disturbed, the desired effect of damping the engine vibration is not provided.

In the first embodiment, the gap S is narrowed as much as possible so that the outer peripheral wall of the movable member 56 and the inner peripheral wall of the partition plate 53 forming the communication hole 53a do not come into contact with each other even if the movable member 56 vibrates in the axial direction. Since it is formed as described above, the pressure difference between the main liquid chamber 51 and the sub liquid chamber 52 can be secured by utilizing the viscous action of the incompressible fluid. Therefore, the movable member 56 and the partition plate 53
Since it is not necessary to install a seal member between the movable member 56 and the movable member 56, the movable member 56 can vibrate in the axial direction without being affected by the seal member. Furthermore, vibration can be smoothly transmitted from the movable member 56 to the incompressible fluid in the main liquid chamber 51. At this time, since the air gap between the upper yoke 73 and the movable coil 75 does not change, the air gap can be reduced and the drive efficiency of the voice coil 70 can be increased, so that the actuator unit 60 can be downsized.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention.
Shown in The same components as those in the first embodiment are designated by the same reference numerals. In the second embodiment, a partition plate 81 is used instead of the partition plate 53 of the first embodiment. The partition plate 81 includes a support assembly 103 and an actuator assembly 104.
The air vent holes 81a and 8b1b, which are closed by the mount rubber 42, are provided on the opposite side of the peripheral portion by 180 ° when assembling.

When the support assembly 103 and the actuator assembly 104 are assembled in liquid, the actuator assembly 104 is held with the direction A in FIG.
When the liquid is introduced from the air vent hole 81a and discharged from the air vent hole 81b, the air in the sub liquid chamber 52 can be discharged. After that, when the support assembly 103 and the actuator assembly 104 are tightened in the liquid with the bolts 66, the air vent holes 81a and 81b are closed by the mount rubber 42, so that the liquid flows in or out from the air vent holes 81a or 81b. Can be prevented. Therefore, after the support portion assembly 103 and the actuator assembly 104 have been assembled, the pressure in the main liquid chamber 51 varies depending on the engine amplitude, as in the normal state shown in FIG. The voltage is varied so as to produce a desired vibration damping effect.

In the second embodiment, two air vent holes 81a and 81b are formed in the partition plate 81, but in the present invention, one or three or more air vent holes may be formed. In the embodiment of the present invention described above, the actuator assembly and the support portion assembly are assembled while bleeding air from the sub-liquid chamber in the state where the partition wall having the air vent hole is assembled to the actuator assembly. The support assembly and the actuator assembly may be assembled while bleeding air from the main liquid chamber with the partition attached to the assembly.

[Brief description of drawings]

FIG. 1 is a sectional view showing an engine mount according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which the first embodiment is assembled.

FIG. 3 is a schematic diagram showing a state in which the engine mount of the first embodiment is mounted on a vehicle.

FIG. 4A is a characteristic diagram showing a pressure fluctuation in the main liquid chamber when air is not mixed in the sub liquid chamber, and FIG. 4B is a characteristic diagram when air is mixed in the sub liquid chamber. It is a characteristic view which shows the pressure fluctuation in the main liquid chamber.

FIG. 5 is a sectional view showing an engine mount according to a second embodiment of the present invention.

[Explanation of symbols]

10 vehicle body 20 engine (power unit) 30 engine mount 51 main liquid chamber 52 sub liquid chamber 53 partition plate (partition wall) 53b recess 53c air bleeding hole 54 air chamber 55 diaphragm (elastic diaphragm) 56 movable member 60 actuator unit (driving means) 63 Damper (support member) 71 Lower yoke (driving means) 72 Ferrite magnet (driving means) 73 Upper yoke (driving means) 75 Moving coil (driving means) 81 Partition plate (partition wall) 81a Air vent hole 81b Air vent hole 100 ECU (control device) ) 101 support assembly (first assembly) 102 actuator assembly (second assembly) 103 support assembly (first assembly) 104 actuator assembly (second assembly)

Claims (3)

[Claims] 1. An engine mount disposed between a vehicle body and a power unit for damping vibration of the power unit, the main liquid chamber having a variable volume and an axially adjacent main liquid chamber. An air penetrating the partition wall is formed in the central portion of the partition wall, which partitions the space between the auxiliary liquid chamber whose volume can be changed and which connects the main liquid chamber in which an incompressible fluid is sealed and the auxiliary liquid chamber. The partition wall provided with a hole is fitted into the communication hole, and a radial gap is formed between the partition wall forming the communication hole and the inner peripheral wall of the partition wall to reciprocate in the communication hole in the axial direction. A movable member that adjusts the pressure in the main liquid chamber by changing the volume of the main liquid chamber, a drive unit that reciprocates the movable member, a control device that controls the drive unit, and a controller that is adjacent to the sub liquid chamber. Is provided on the axially opposite side to the main liquid chamber. An engine mount characterized in that the air chamber opened to the atmosphere and the sub liquid chamber are liquid-tightly partitioned, and an elastic diaphragm that reciprocates together with the movable member is provided, and can be divided and assembled with the partition as a boundary. . 2. A recess is provided on the side of the sub-liquid chamber of the partition wall,
The engine mount according to claim 1, wherein the air vent hole is formed at an upper position of the concave portion when the main liquid chamber side of the partition wall is upward. 3. The engine mount according to claim 1, wherein the air vent hole is closed when the assembly of the engine mount is completed.