JPH0637137B2 - Power unit mounting device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting device for mounting a power unit such as an engine on a base such as a vehicle body of a vehicle. The present invention relates to an improvement in which deformations of paired mounts arranged on both sides are associated with each other.

(Prior Art) Conventionally, as a mounting device of this type, as disclosed in, for example, Japanese Patent Application Laid-Open No. 58-161617, it is arranged on both left and right sides of a power unit with a rotating shaft interposed therebetween. With the enclosed upper and lower chambers,
A leg of the power unit is connected to the partition walls of the upper and lower chambers, and a pair of mounts for elastically supporting the power unit with respect to the base are provided, and an upper chamber of the left mount and a lower chamber of the right mount, and a lower chamber and a right mount of the left mount. The upper chamber is made to communicate with each other by independent conduits, and for the bounce vibration of the power unit, low bounce rigidity is obtained by the moving spring constant when the fluid moves between the upper and lower chambers communicating with each other of the mount, while the power unit is obtained. It is known that the roll rigidity is increased by the above-mentioned fluid movement between the upper and lower chambers against the roll vibration.

(Problems to be solved by the invention) However, in this conventional one, since the purpose is essentially to increase the roll rigidity, the high roll rigidity increases the transmissibility of the fluctuation torque of the power unit to the base, It is difficult to reduce vibration and noise.

On the other hand, as a conventional example other than the above, for example, US Pat.
As disclosed in Japanese Patent No. 705118, each of the mounts arranged on both sides of the rotation axis of the power unit as described above is configured to have one fluid chamber in which an incompressible fluid is enclosed, and It is known that a transient large torque fluctuation of a power unit is attenuated by an orifice by connecting a fluid chamber of a mount with a conduit having an orifice.

By the way, for the purpose of reducing the roll rigidity of the mounting device, the inventors of the present invention provide a basic configuration of the latter prior art described above, that is, fluid chambers of mounts arranged on both sides of a shaft of a power unit. When various studies were repeated on the structure in which the pipes communicate with each other, the roll rigidity of the mounting device is shown by the broken line in Fig. 3 according to the change in the frequency with the torque fluctuation of the power unit due to the resonance development of the fluid in the pipe. It was found that it changes as shown by. That is, the roll spring constant, which represents the roll rigidity, is: I) In the low frequency range, the fluid moves inside the conduit, so it is almost equal to the static spring constant K when communicating with the fluid chamber, and it decreases with the increase in frequency and vibrates. The minimum value is reached with the number fa.

II) When the frequency increases beyond the above minimum frequency fa, the fluid's inertial force, which is proportional to the square of the acceleration, makes it difficult for the fluid to flow in the conduit. It becomes equal to the non-communication spring constant (1 + N) K (N is the expansion / movement spring constant ratio of the elastic wall in the mount) when the fluid chamber is not conducting, which is a few fe.

III) It further increases beyond the above-mentioned frequency fe and reaches the maximum value at the natural frequency fn of the fluid in the conduit.

IV) In a frequency range higher than the natural frequency fn, the frequency decreases as the frequency increases, and gradually approaches the non-communication spring constant (1 + N) K in a state where the fluid does not flow in the conduit.

Considering the above results, the roll rigidity can be reduced when the roll frequency of the power unit is in the low frequency range, but in the high frequency range, the roll rigidity is as high as when not in communication, so the roll rigidity is always kept low. You will not be able to.

Therefore, the present applicant previously set the rigidity of a part of the wall of the fluid chamber in each mount to be partially low in the mounting device in which the fluid chambers of both mounts are communicated with each other by a conduit as described above. By controlling the deformation of the low-rigidity wall, the low-rigidity wall absorbs the volume change of the fluid chamber in the high-frequency range of the roll vibration mode, and at the same time, the volume change in the low-frequency range is between the two mounts. Has been proposed by Japanese Patent Application No. 59-268848 and Japanese Patent No. 59-268848 in which the spring characteristic of the power unit during rolling can be kept soft regardless of the frequency. reference).

That is, in the configuration of the above-mentioned mounting device, a pair of mounts in which an incompressible fluid is sealed for elastically supporting the power unit on the base are arranged on both sides of the rotation axis of the power unit, and The fluid chambers of the both mounts are communicated with each other to allow the movement of the fluid and to provide a conduit for associating the pressure change of the fluid chambers. Further, a part of the wall of each fluid chamber is formed into an elastic film that deforms in response to a change in the pressure in the fluid chamber, and elastic film deformation restraining means for selectively preventing deformation of the elastic film is provided. It is a thing.

However, in that case, as the elastic film deformation restraint means, for example, a pressing member such as a plunger that moves by the attraction force of an electromagnet is provided, and by the movement of the pressing member, the elastic film is pressed against another member to restrain the deformation. When I did
The elastic membrane can be switched from the non-constrained state to the restrained state in a short time with good responsiveness, but on the other hand, it is difficult to control the moving speed of the pressing member, so the elastic film is suddenly pressed by the pressing member. However, the impact force may cause an operational shock, and there is room for practical improvement.

The present invention has been made in view of the above points, and an object thereof is to elastically apply a fluid pressure instead of pressing an elastic film against another member by the movement of the pressing member to restrain its deformation as described above. By pressing the membrane to restrain its deformation, the speed of pushing the elastic membrane at the time of restraining the elastic membrane is adjusted so that the operating shock can be minimized.

(Means for Solving the Problem) In order to achieve the above object, the solution means of the present invention has the configuration of the above-mentioned proposal, that is, basically, an incompressible fluid elastically supporting a power unit on a base is enclosed. Mounted mounts, a conduit for associating a pressure change between the fluid chambers of the mounts, an elastic membrane forming a part of the wall of each fluid chamber, and an elastic membrane selectively preventing deformation of the elastic membranes. In a mounting device provided with deformation restraint means, the elastic membrane deformation restraint means is provided adjacent to the elastic membrane on a side opposite to the fluid chamber with respect to the elastic membrane, and a variable volume working fluid chamber is provided on the elastic membrane side. , And a working fluid control means for controlling the supply and discharge of the working fluid to and from the working fluid chamber to change the volume of the working fluid chamber.

(Operation) According to the present invention, according to the present invention, the working fluid is controlled by the working fluid control means of the elastic membrane deformation restraining means in the high frequency range where the fluid does not move in the conduit due to the increase of the vibration frequency during the roll vibration of the power unit. The working fluid in the chamber is discharged, the volume thereof is reduced, and the elastic film is not deformed by the fluid pressure in the working fluid chamber, so that the elastic film is allowed to deform. In this state, the volume change of the fluid chamber of each mount is absorbed by the deformation of the elastic film, and the mounting device is kept at low roll rigidity. In the low frequency range, the working fluid is supplied to the working fluid chamber by the control of the working fluid control means to increase its volume, and the elastic film is pressed by the fluid pressure in the working fluid chamber to prevent its deformation. . In this state, the volume change of the fluid chamber of each mount is absorbed as the fluid moves through the conduit, and the roll effect is minimized, and the roll effect is kept as it is to keep the roll rigidity low. Be drunk Therefore, the spring characteristic at the time of rolling can be always softened.

In this case, the supply / discharge of the working fluid to / from the working fluid chamber disposed adjacent to the elastic membrane is controlled to switch the elastic membrane to the restrained state or the non-restrained state, so that the working fluid supply rate to the working fluid chamber can be easily adjusted. When the elastic membrane is restrained, the working shock can be reduced by reducing the supply speed of the working fluid to the working fluid chamber near the restrained state.

(Example) Hereinafter, the Example of this invention is described based on drawing.

FIG. 1 shows an overall configuration of an embodiment applied to mounting a vehicle engine on a vehicle body, 1 is a vehicle body as a base, 2 is a power unit mounted and supported on the bottom of the engine room of the vehicle body 1. In the engine, brackets 3 and 3 extending in a substantially horizontal direction are integrally provided on both right and left side surfaces of the engine 2 such that the rotary shaft of the engine 2 or the crankshaft 2a is sandwiched between the brackets 3 and 3 and the vehicle body 1. Mounts 4 and 4 for elastically supporting the engine 2 with respect to the vehicle body 1 are arranged in the space, that is, on both sides of the crankshaft 2a of the engine 2.

Each of the mounts 4 is fixed to the vehicle body 1 and has a cylindrical case 5 whose upper and lower surfaces are open, and a rubber which seals the upper opening of the case 5 and is connected to the brackets 3 through connecting bolts 9. And an elastic wall 6 made of, for example, the lower surface opening of the case 5 is sealed by an elastic film 7 made of thin rubber, and the case 5, the elastic wall 6 and the elastic film 7 are provided.
To form a closed fluid chamber 8.
A non-compressible fluid (liquid) is enclosed inside. Therefore, each elastic film 7 forms a part of the wall of the fluid chamber 8,
The fluid chamber 8 is provided so as to be deformed according to changes in the internal pressure.

In addition, the conduits 10 are provided in the cases 5 and 5 of the mounts 4 and 4, respectively.
Are connected to each other, and the conduit 10 connects the fluid chambers 8 and 8 of the mounts 4 and 4 with each other to allow the movement of the fluid and associate the pressure change of the fluid chambers 8 and 8. Is configured.

Further, 11 is a stopper plate that regulates upward deformation of each elastic film 7 by a predetermined amount or more. The stopper plate 11 is provided in the fluid chamber 8 and a part of the plate allows movement of fluid. The communication holes 12, 12, ...

On the other hand, below the elastic film 7, a substantially cup-shaped support plate 13 whose outer edge is fixed to the lower end of the case 5 of the mount 4 is arranged as shown in detail in FIG. Inside the supporting plate 13, an elastic member 14 made of rubber or the like having substantially the same shape as the elastic film 7 is disposed adjacent to the elastic film 7 via a spacer 15 having a predetermined thickness, and the outer edge portion of the elastic member 14 is a spacer. 15, the outer edge of the elastic film 7 and the outer edge of the stopper plate 11 are fixed to the lower end of the case 5. The space between the elastic film 7 and the elastic member 14 is communicated with the atmosphere, and deformation of the elastic film 7 is allowed by this communication, while the space below the elastic member 14, that is, the elastic film 7 is The space adjacent to the elastic film 7 on the opposite side of the upper fluid chamber 8 is formed as a liquid-tight working fluid chamber 16. The working fluid chamber 16 is connected to a reserve tank 19 for storing a magnetic fluid as a working fluid in which magnetic powder is mixed in a fluid such as viscous oil via a communication pipe 18 having an orifice 17, The magnetic fluid in the reserve tank 19 is supplied to the inside of the working fluid chamber 16, and the elastic member 14 is bent and deformed by the fluid pressure of the supplied magnetic fluid to reduce the volume of the working fluid chamber 16. It changes to the elastic film 7 side.

Further, the inner bottom portion of the working fluid chamber 16 (the inner surface of the support plate 13) is attracted to the magnetic fluid, so that the working fluid chamber 1
Electromagnet 20 as a working fluid control means for changing the volume of working fluid chamber 16 by controlling the supply and discharge of magnetic fluid to and from
Is fitted. The electromagnets 20 are connected to a controller (not shown) that operates according to the operating state of the engine 2, and the controller controls the power supply to each electromagnet 20 according to the operating state of the engine 2 to supply the electromagnets 20. When power is not supplied, the working fluid chamber 1 is driven by the pressure of the elastic member 14.
6, the magnetic fluid in 6 is discharged to reduce the volume of the working fluid chamber 16, and the elastic member 14 is isolated from the elastic film 7 to allow the elastic film 7 to be deformed. To attract the magnetic fluid into the fluid chamber 16 to increase the volume of the working fluid chamber 16, bend the elastic member 14 as the upper wall of the working fluid chamber 16 upward, and press the elastic film 7 against the stopper plate 11. The elastic film deformation restraint means 21 is configured to prevent the deformation thereof, and thus selectively prevent the deformation of the elastic film 7.

Next, the operation of the above embodiment will be described. The frequency of the engine 2 during roll vibration is higher than the frequency f ₂₅ corresponding to the static spring constant K when both mounts 4 and 4 are in communication, as shown in FIG. In a high high frequency range, the electromagnets 20 of the elastic film deformation restraint means 21 are kept in a non-powered state by the control of the controller, and the magnetic fluid in the working fluid chamber 16 is discharged to the reserve tank 19 by the pressure of the elastic member 14. The volume of the working fluid chamber 16 is held in a reduced state, the elastic member 14 is held in a normal position slightly apart from the elastic film 7, and the elastic film 7 is in a state in which it can be freely deformed. Therefore, due to the roll vibration, the fluid does not move through the conduit 10 between the fluid chambers 8, and each elastic film 7 is deformed to absorb the volume change of the fluid chamber 8. As a result, the roll spring constant of the mounting device is equal to the static spring constant K and the film rigidity ΔK of the elastic film 7 even though the fluid chambers 8 and 8 of both mounts 4 and 4 are communicated by the conduit 10.
Becomes K + ΔK, which is kept low regardless of the change in the vibration frequency.

On the other hand, in the low frequency range in which the roll frequency is equal to or lower than the frequency f ₂₅ , the electromagnet 20 is supplied with power by the controller to generate an attractive force, and the attractive force of the electromagnet 20 attracts the magnetic fluid so that the reserve tank 19 To working fluid chamber 16
Is supplied into the working fluid chamber 16, and the magnetic fluid flows into the working fluid chamber 16 to increase the fluid pressure in the working fluid chamber 16.
The volume increases and the elastic member 14 is bent and deformed upward, and the elastic film 7 is pressed against the stopper plate 11 by the deformation of the elastic member 14, and the deformation is prevented.
Therefore, the fluid in both fluid chambers 8 and 8 moves through the conduit 10 in accordance with the roll vibration of the engine 2, and the change in volume of the fluid chamber 8 is absorbed by the fluid movement, and the solid line in FIG. The roll rigidity can be kept extremely low by effectively utilizing the maximum effect range in the frequency characteristics of the mount rigidity of the roll mode shown. Therefore, it is possible to reduce the roll rigidity from the low range to the high range of the roll vibration frequency to reduce the transmission rate of the roll vibration of the engine 2 to the vehicle body 1, and to reduce the vibration and noise of the vehicle body 1.

In that case, since the supply and the discharge of the magnetic fluid to the working fluid chamber 16 adjacent to the elastic film 7 are controlled by controlling the power supply to the electromagnet 20, the elastic film 7 is switched to the restrained state or the non-restrained state. When electromagnet 20
The supply rate of the magnetic fluid to the working fluid chamber 16 can be easily controlled by changing the suction force by controlling the amount of power supplied to the working fluid chamber 16, and the supply rate becomes closer to other states when the elastic membrane 7 is in the constrained state. By making such adjustments, it is possible to effectively reduce the operational shock while switching the elastic film 7 to the restrained state in a short time with good responsiveness.

Further, since the orifice 17 is formed in the middle of the communication pipe 18 that connects the working fluid chambers 16 and the reserve tank 19, the force input from the engine 2 to each mount 4 when the elastic film 7 is restrained is When the fluid pressure in the fluid chamber 8 fluctuates, the elastic film 7 is pressed downward due to the increase in the fluid pressure, and the magnetic fluid in the working fluid chamber 16 is discharged to the reserve tank 19 through the communication pipe 18. Can be attenuated by the orifice 17, and
The attraction force of the electromagnet 20, that is, the holding force for holding the elastic film 7 in the restrained state can be reduced.

Further, when each electromagnet 20 is in the non-power supply state and the deformation of the elastic film 7 is allowed, a large static torque is applied to the mounting device by the torque reaction force of the engine 2 as during acceleration in a low gear of the vehicle. When the volume of each fluid chamber 8 changes, the fluid in both fluid chambers 8 and 8 moves through the conduit 10, and the change in volume of the fluid chamber 8 is absorbed by the fluid movement. It is kept in the same condition as when there is no load. Therefore, the fluid chambers 8 and 8 of both mounts 4 and 4
Is not communicated with the conduit 10, the elastic film 7 hits the stopper plate 11 or the elastic member 14 in the normal position to increase the roll rigidity when the same static torque is applied, whereas the neutral state of the elastic film 7 causes the roll rigidity to increase. The rigidity can be kept low, so that the low range of the vehicle body vibration and noise can be achieved even when the static torque is displaced.

Further, when the torque largely changes during a sudden acceleration / deceleration of the vehicle or during a gear shift, each elastic film 7 is deformed due to a delay in the temporal movement of the fluid in the conduit 10 during a transition until the torque reaches a steady state. After hitting the stopper plate 11 or the elastic member 14 in the normal position, the fluid flows in the conduit 10 and moves between the two fluid chambers 8, 8, so that the roll rigidity can be increased and the engine 2 Vibration and shock can be mitigated by damping the excessive movement.
At that time, if an orifice is arranged in the conduit 10, the time delay of the fluid in the conduit 10 is further promoted, so that the vibration and the shock caused by the excessive movement of the engine 2 become remarkable. Can be relaxed.

In addition, at the time of bounce vibration due to unbalance in the engine 2 or traveling vibration of the vehicle, the fluid chamber 8 in each mount 4
The volume change of is absorbed by the deformation of each elastic film 7 as in the roll vibration mode. Therefore, it is possible to keep the bounce rigidity of the mounting device low and reduce the transmissibility of the bounce vibration of the engine to the vehicle body 1.

In the above embodiment, the working fluid is magnetic fluid, and the magnetic fluid is attracted by the electromagnet 20 to change the volume of the working fluid chamber 16. However, the working fluid is liquid such as hydraulic oil or air, The volume of the working fluid chamber may be changed by pressurizing and supplying them to the working fluid chamber while adjusting the supply amount from the supply source, and it is possible to obtain the same effect as the above embodiment.

(Effects of the Invention) As described above, according to the present invention, the fluid chambers of the fluid-filled mounts arranged on both sides of the rotary shaft of the power unit are communicated with each other by conduits, and a part of the wall of each fluid chamber is elastic. In the high frequency range of roll vibration in the power unit, it is possible to absorb the volume change of each fluid chamber by the deformation of the elastic film to reduce the roll rigidity in the high frequency range of the roll vibration in the power unit, and in the low frequency range, In a mounting device in which the volume change of each fluid chamber due to the restraint of the elastic film is absorbed by the fluid movement between the two fluid chambers and the low roll rigidity is maintained, a variable working fluid chamber is provided adjacent to the elastic film. By changing the volume of the working fluid to and from the working fluid chamber to switch the elastic membrane to the restrained state or the non-restrained state, the switching speed of the elastic membrane to the restrained state can be controlled. It can be easily adjusted, and the operation shock at the time of switching can be effectively reduced by suppressing the switching speed near the elastic membrane restrained state.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a schematic explanatory view showing the entire structure, FIG. 2 is an enlarged sectional view of an essential part, and FIG. 3 is an explanatory view showing vibration frequency characteristics of roll rigidity. . 1 ... Body, 2 ... Engine, 2a ... Crankshaft, 4
...... Mount, 7 ... Elastic membrane, 8 ... Fluid chamber, 10 ...
Conduit, 16 ... Working fluid chamber, 20 ... Electromagnet, 21 ...
Elastic membrane deformation restraint means.

Claims (2)

[Claims] 1. A mount which is arranged on both sides of a rotation shaft of a power unit and elastically supports the power unit with respect to a base. Each mount contains an incompressible fluid. The fluid chambers are communicated with each other to allow the movement of fluid and form a part of the wall of each fluid chamber and a conduit for associating the pressure change of both fluid chambers, and deformed according to the change of the fluid chamber pressure An elastic film, and an elastic film deformation restraint means for selectively preventing deformation of the elastic film,
The elastic membrane deformation restraint means is provided on the side opposite to the fluid chamber with respect to the elastic membrane and adjacent to the elastic membrane. And a working fluid control means for changing the volume of the working fluid chamber by controlling the mounting unit of the power unit. 2. The fluid supplied to and discharged from the working fluid chamber is a magnetic fluid, and the working fluid control means for controlling the supply and discharge is an electromagnet arranged in the working fluid chamber. Mounting device for the described power unit.