JPH0718467B2 - Power unit mounting device - Google Patents

Description

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 to suppress vibrations of the power unit from being transmitted to the base. It is about improvement.

(Prior Art) Conventionally, as a mounting device of this type, as disclosed in, for example, Japanese Utility Model Laid-Open No. 58-86937, a mounting device is mounted between a vehicle body mounting member mounted on a vehicle body and a power unit mounting member mounted on an engine. In addition to explaining the elastic member, by providing a mass member in the elastic member, by utilizing the resonance development of the mass member in the elastic member, combustion noise, gear noise, etc. can be generated from various vibrations generated in the engine. It is known that a so-called low-pass filter is formed by reducing the high-frequency vibration of 80 to 100 Hz or more, which is the muffled sound contained therein.

(Problems to be Solved by the Invention) However, although the conventional one has the excellent sound insulation function and the vibration damping function as described above, the resonance frequency of the mass member is used because the resonance development of the mass member is used. There is a problem that the amplitude increases in the range and the vibration transmissibility to the vehicle body increases extremely. This resonance frequency is determined by the weight of the mass member, the elastic coefficient of the elastic member, and the like, but is generated in the vicinity of 50 Hz, and the sound wave of this frequency becomes an uncomfortable muffled sound close to the vibration that presses the ear. For this reason, usually, the resonance frequency is set to a high value, and an increase in the vibration transmissibility at the resonance frequency is dealt with so that the body side does not produce a muffled sound due to the increase in rigidity. The degree of freedom of will be limited.

A main object of the present invention is to bring the mass member into contact with the stopper member when vibrating in the above-mentioned resonance frequency range so as to mechanically suppress the resonance development itself of the mass member. While taking advantage of the effect as a low-pass filter that can reduce the vibration transmissibility in the high frequency range above, the vibration transmissibility in the resonance frequency range of the mass member can be achieved without affecting the degree of freedom on the base side in the mounting device itself. Is to be effectively reduced.

By the way, in that case, if the clearance formed between the mass member and the stopper member is too small, the mass member hits the stopper member even in a frequency range other than the resonance frequency range, and its vibration is restricted, and the elastic member of the mass member is suppressed. On the other hand, if the clearance is too large, the restriction by the stopper member is not performed and the original purpose cannot be achieved. Therefore, it is necessary to always manage the clearance to an appropriate value regardless of the load acting from the power unit and the change of the spring constant of the elastic member in the loaded state of the parallel unit.

Therefore, as described above, an object of the present invention is to enable the clearance between the mass member and the stopper member for suppressing the vibration in the resonance frequency range to be maintained at an appropriate value with a simple structure regardless of load changes. It is in.

(Means for Solving the Problem) In order to achieve this object, the solution means of the present invention is a base mounting member mounted on a base as a mounting device for mounting a power unit such as an engine on a base such as a vehicle body. And a power unit mounting member to be mounted on the power unit, and a mass member interposed between the both mounting members and elastically supported by both mounting members via an elastic member.

A cylinder formed in the mass member; a piston member slidably fitted in the cylinder in the same direction as the vibration direction of the mass member to define a fluid chamber inside the cylinder; A stopper member that suppresses the piston member from sliding more than a predetermined amount, a partition plate that partitions the fluid chamber into a first chamber and a second chamber, and a partition plate that is provided on the partition plate and that includes the first chamber and the second chamber. And a communicating orifice, and the resonance frequency of the fluid in the orifice is set lower than the resonance frequency of the mass member.

(Operation) With the above configuration, when the power unit is mounted on the mounting device, the load from the power unit causes the elastic member to be compressed and deformed, and the clearance between the mass member and the stopper member tends to be reduced. However, in the present invention, a piston member capable of contacting a stopper member is fitted in the cylinder in the mass member, and the fluid chamber formed in the cylinder by the piston member is divided into a first chamber and a second chamber. Since the partition plate is provided with an orifice, due to the compressive deformation of the elastic member,
The piston member slides in the cylinder while exchanging fluid through the orifice to move relatively to the mass member, and the relative movement between the piston member and the mass member compensates for the decrease in the clearance. The clearance between the member and the stopper member can be maintained at an appropriate value.

Since the resonance frequency of the fluid in the orifice is set lower than the resonance frequency of the mass member, even if the mass member resonates with the vibration from the power unit, in the resonance frequency range, the orifice is In the so-called clogging state in which the fluid does not flow at all, the piston member in the cylinder vibrates integrally with the mass member. Therefore, even if the mass member resonates in the resonance frequency range, the stopper member forcibly suppresses the vibration having a predetermined amplitude or more in the resonance frequency range, and the vibration transmissibility of the entire mounting device is suppressed, and thus the ear is suppressed. The uncomfortable low-frequency muffled sound that is compressed can be effectively reduced by the mounting device itself. Further, the mass member itself does not vibrate in the frequency range above the resonance frequency, and the original high frequency vibration (muffled sound) can be reduced by the low-pass filter effect accompanying the behavior of the mass member.

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

FIG. 1 shows a mounting device M according to an embodiment of the present invention.
This mounting device M is used for mounting an engine E of an automobile as a power unit on a vehicle body B as a base (all of which are partially shown), and a predetermined amount of the engine E is used. Parts and components of the vehicle body B (eg cross members and side members)
Is intervened between.

In the figure, reference numeral 1 denotes a circular engine mounting plate to be mounted on the engine E. A circular center hole 2 is provided at the center of the mounting plate 1, and a bolt insertion hole 3 is provided at a predetermined portion on the outer peripheral portion.
Are attached to the engine E, and the engine mounting plate 1 is attached to the engine E by screwing and fastening the mounting bolts 4 inserted through the bolt insertion holes 3 into the engine E. Reference numeral 5 denotes a disk-shaped vehicle body mounting plate which is disposed below the engine mounting plate 1 and is mounted on the vehicle body B. A bolt insertion hole 6 is formed in the center of the disk mounting plate 6 and is inserted into the bolt insertion hole 6. The vehicle body mounting plate 5 is mounted on the vehicle body B by screwing the mounting bolts 7 onto the vehicle body B.

Reference numeral 8 denotes a substantially cylindrical mass member having a predetermined weight disposed between the engine mounting plate 1 and the vehicle body mounting plate 5,
The mass member 8 has a ring-shaped mounting flange portion 8a on its outer periphery.
And a lower end surface of a cylindrical engine-side elastic member 9 disposed so as to surround the outer periphery of the upper half of the mass member 8 integrally with the upper surface of the mounting flange portion 8a facing the engine mounting plate 1. The upper end surface of the elastic member 9 is fixed to the outer peripheral portion of the lower surface of the engine mounting plate 1. Further, an upper end surface of a cylindrical body-side elastic member 10 arranged so as to surround the outer periphery of the lower end portion of the mass member 8 is integrally fixed to the lower surface of the mounting flange portion 8 (a surface facing the vehicle body mounting plate 5). The lower end surface of the elastic member 10 is fixed to the outer peripheral surface of the upper surface of the vehicle body mounting plate 5. With the above structure, the mass member 8 has two elastic members 9 and 10 for both mounting plates 1 and 5. It is elastically supported through.

Further, a substantially hat-shaped support member 11 is fixed to the outer peripheral portion of the upper surface of the engine mounting plate 1 concentrically and integrally with the engine mounting plate 1 by an outward flange portion 11a at the lower end thereof. A central hole 11b is formed therethrough.

A cylinder 12 is formed inside the mass member 8 and extends in the same direction (vertical direction) as the vibration direction of the mass member 8 and opens on the lower surface of the mass member 8. The opening of the cylinder 12 is closed by a diaphragm 13. Has been done. Further, a piston 15 is fitted in the cylinder 12 in a sliding material in the same direction as the vibration direction of the mass member 8, and a liquid as a fluid is sealed in the cylinder 12 by the piston 15 and the diaphragm 13. The chamber 14 is compartmentalized. The piston 15 has a piston rod 16 protruding above the mass member 8. The piston rod 16 passes through the center hole 2 of the engine mounting plate 1 and extends above the mounting plate 1, and the upper end thereof is provided. A male screw portion 16a is formed on the male screw portion 16a, and a circular rod mounting plate 17 arranged in the support member 11 is screwed and fastened at its center portion by a nut 18 so that the screw feed can be adjusted. A ring-shaped first stopper member 19 made of an elastic body is fixed to the outer peripheral edge of the upper surface of the rod mounting plate 17 so as to be able to abut on the lower surface of the upper wall of the support member 11,
A ring-shaped second stopper member 20 made of an elastic material is fixed to the outer peripheral edge of the lower surface so as to be able to contact the peripheral edge portion of the center hole 2 on the upper surface of the engine mounting plate 1. Further, the two stopper members 19 and 20 are integrally formed with a disc-ring-shaped elastic member 21 attached to the rod mounting plate 17 so as to wrap the outer peripheral end face thereof, and the elastic member 21 is provided with each of the elastic members 9 and 10. The outer peripheral surface is fixedly supported by the inner peripheral surface of the supporting member 11, and when the engine E is vibrated by the vibration, the mass member 8 resonates with the engine vibration at a frequency f ₁ (for example, 50 Hz). When this occurs, the first stopper member 19 fixed to the upper surface of the rod mounting plate 17 that vibrates integrally with the mass member 8 at a large amplitude due to the resonance is fixed to the lower surface of the upper wall of the support member 11 and also to the mounting plate 17. Second stopper member 20 fixed to the lower surface
Are brought into contact with the upper surface of the engine mounting plate 1 to suppress the vibration of the mass member 8 having a predetermined amplitude or more in the resonance frequency range.

Further, a circular partition plate 22 is provided between the diaphragm 13 that closes the lower end of the cylinder 12 of the mass member 8 and the lower end surface of the mass member 8, and the liquid chamber 14 in the cylinder 12 serves as the upper chamber 14a, which serves as the first chamber. And a lower chamber 14b as a second chamber, which is provided in a liquid-tight manner so as to be partitioned from each other.
An orifice 23 that communicates the lower chamber 14b with the lower chamber 14b is formed so that the resonance frequency of the liquid in the orifice 23 (determined by its inner diameter) is much lower than the resonance frequency f of the mass member 8, for example. It is set to about 10Hz.

Therefore, in the above embodiment, the clearance d ₁ between the first stopper member 19 and the upper wall lower surface of the support member 11 in the mounting device M and the clearance between the second stopper member 20 and the upper surface of the engine mounting plate 1 are increased. When d ₂ is set, for example, in a loaded state in which the engine E is mounted on the mounting device M, the male screw portion on the upper end of the piston rod 16 protruding upward from the mass member 8 is set.
By screwing the nut 18 onto the 16a, the clearances d ₁ and d ₂ are adjusted to proper values.

That is, in that case, both elastic members 9, 10 are compressed and deformed by the load from the engine E, and the mass member 8 approaches the engine mounting plate 1 as the elastic members 9, 10 are deformed.
Clearance between the first stopper member 19 and the support member 11
It tends to change in the direction in which d ₁ decreases and in the direction in which the clearance d ₂ between the second stopper member 20 and the engine mounting plate 1 increases. However, since the stopper members 19 and 20 are attached to the rod mounting plate 17 at the upper end of the piston rod 16 that can be opposed to the mass member 8, the piston 15 is compressed by the elastic deformation of the elastic members 9 and 10. The cylinder 12 of the mass member 8 slides while exchanging liquid between the upper chamber 14a and the lower chamber 14b via the orifice 23 of the liquid chamber 14, and stops when the load is in an equilibrium state.
Therefore, once the clearances d ₁ and d ₂ are set by such relative movement of the piston 15 with respect to the mass member 8, the load of the engine E and the elastic coefficients of the elastic members 9 and 10 may fluctuate or vary. also regardless of their, that the clearance d _1, d ₂ is kept constant and thus constantly kept at a proper value with clearance d _1, d ₂ with a simple structure for the stopper member 19 and 20 of the mass member 8 it can.

When the engine E is operated in such a manner that the clearances d ₁ and d ₂ between the mass member 8 and the stopper members 19 and 20 are maintained at proper values, the engine E is driven by the vibration of the operation. The mass member 8 in the mounting apparatus M also vibrates due to the exciting force of. In this case, the mass member 8 resonates with the vibration when the frequency of the engine vibration is at a predetermined frequency f determined according to the weight of the mass member 8 and the elastic coefficients of the elastic members 9 and 10. The resonance frequency (10 Hz) of the liquid in the orifice 23 in the cylinder 12 of the member 8 is the resonance frequency f (50 Hz) of the mass member 8.
Since it is set lower than the resonance frequency f of the mass member 8, at a stage higher than the resonance frequency of the liquid in the orifice 23, the liquid is not transferred through the orifice 23 and the orifice 23 Is clogged, and the piston 15 and piston rod 16 are
, And is vibrated similarly to the mass member 8. Therefore, when the amplitude of the mass member 8 becomes large in the resonance frequency f range of the mass member 8 as shown by the broken line in FIG. 2, the mounting device M increases with the increase of the amplitude.
The first stopper member 19 fixed to the upper surface of the rod mounting plate 17 is attached to the lower surface of the upper wall of the support member 11, and the second stopper member 20 fixed to the lower surface of the mounting plate 17 is attached to the engine mounting plate 1.
To contact the upper surface of each. Due to the contact with the upper and lower stopper members 19 and 20, the mass member 8 can no longer vibrate with a larger amplitude, and the increase in the amplitude is suppressed. As a result, as shown by the solid line in FIG. It is possible to suppress the vibration transmissibility transmitted to the. As a result, even if the resonance frequency f ₁ of the mass member 8 is set to an uncomfortable frequency range (approximately 50 Hz) that presses the ear, the vibration is transmitted to the vehicle body B by the mounting device M itself. Can be reduced.

Further, when the vibration frequency of the engine E is higher than the resonance frequency f range of the mass member 8 and in the frequency range that causes muffled sound, the vibration of the mass member 8 itself is stopped, and the vibration from the engine E is It is blocked by the mass member 8. As a result, the mounting device M exhibits the function of a low-pass filter that cuts high-frequency vibrations as shown in FIG. 2, and thus the vibration transmissibility to the vehicle body B can be suppressed and the muffled sound can be reliably reduced. In addition, in FIG.
The alternate long and short dash line shows the vibration transmissibility characteristic with respect to the vibration frequency when only the elastic member is interposed between the two mounting plates 1 and 5.

In each of the above examples, a liquid was used as the fluid,
A gas such as air may be adopted. Also, both stopper members
19, 20 are fixed to the upper and lower surfaces of the rod mounting plate 17 that is integral with the piston rod 16, but conversely, the stopper members 19, 20
It is needless to say that the mounting portions of the above may be changed to the lower surface of the upper wall of the support member 11 facing the rod mounting plate 17 and the upper surface of the engine mounting plate 4.

In the above embodiment, the engine mounting plate 1 is arranged on the upper side and the vehicle body mounting plate 5 is arranged on the lower side.
The positions of 1 and 5 may be reversed, and the same effects as those of the above-described respective embodiments can be obtained.

Further, in the above-described embodiment, the case of the mounting device M that elastically supports the engine E on the vehicle body B has been described, but the present invention elastically supports the power unit other than the engine on the base in order to reduce vibration, noise and the like. It goes without saying that the present invention can also be applied to a mounting device configured to do so.

(Effects of the Invention) As described above, according to the present invention, in a mounting device that is arranged between a power unit and a base and has a mass member built in an elastic member, a cylinder formed in the mass member A piston member that is slidably fitted in the cylinder in the same direction as the vibration direction of the mass member to define a fluid chamber inside the cylinder; and a stopper that suppresses the piston member from sliding more than a predetermined amount. A member, a partition plate that divides the fluid chamber into a first chamber and a second chamber, and an orifice that is provided in the partition plate and connects the first chamber and the second chamber are provided. By setting the resonance frequency of the lower than the resonance frequency of the mass member, the original low-pass filter effect of the mounting device in which the mass member is built in the elastic member is utilized to utilize the power unit. While effectively reducing the vibration that may be a muffler sound, the mounting device itself suppresses the increase in the vibration transmissibility in the resonance frequency range of the mass member, creating an uncomfortable low-frequency muffled sound that presses the ear. The clearance between the mass member and the stopper member can be maintained and managed at a proper value at all times regardless of the load of the power unit and the variation of the elastic coefficient of the elastic member. Therefore, the sound insulation of the mounting device can be achieved with a simple structure. It is possible to contribute to a great improvement in the vibration resistance and the vibration damping property.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a sectional view of a mounting device, and FIG. 2 is a characteristic diagram showing a vibration transmissibility characteristic with respect to a vibration frequency of the mounting device. M: Mounting device, 1 ... Engine mounting plate, 5
…… Vehicle mounting plate, 8 …… Mass member, 9 …… Engine side elastic member, 10 …… Vehicle side elastic member, 12 …… Cylinder, 14…
… Liquid chamber, 15 …… Piston, 16 …… Piston rod, 19
...... First stopper member, 20 ...... Second stopper member, 17 ...
… Elastic members, d ₁ , d ₂ …… Clearance, E …… Engine, B …… Car body.

Claims (1)

[Claims] 1. A mounting device for mounting a power unit such as an engine on a base such as a vehicle body,
A base mounting member mounted on the base, a power unit mounting member mounted on the power unit, a mass member interposed between the mounting members and elastically supported by the mounting members via elastic members, and the mass member. A cylinder formed therein, a piston member slidably fitted in the cylinder in the same direction as the vibration direction of the mass member to define a liquid chamber inside the cylinder, and a predetermined amount or more of the piston member A stopper member for suppressing the sliding of the fluid chamber, a partition plate that partitions the fluid chamber into a first chamber and a second chamber, and an orifice that is provided in the partition plate and that connects the first chamber and the second chamber. A mounting device for a power unit, characterized in that the resonance frequency of the fluid in the orifice is set lower than the resonance frequency of the mass member.