JPH0131796Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an engine mount that elastically supports an automobile engine and a power plant including a transmission to the vehicle body, and is particularly suitable for an engine suitable for a horizontally mounted front-wheel drive vehicle. It's about the mount.

Prior Art In terms of vibration and noise countermeasures for automobiles, it is extremely important how to elastically support the power plant on the vehicle body, and the vibration-proofing performance of the engine mount interposed between them is important in reducing vibrations including the power plant. It greatly influences the behavior of the system.

In one type of engine mount, an outer cylinder metal fitting is placed concentrically at a predetermined distance outside an inner cylinder metal fitting, and the outer cylinder metal fitting and the inner cylinder metal fitting are connected via a rubber elastic body. 2. Description of the Related Art An engine mount is known that has a structure in which an inner cylindrical metal fitting is placed between the metal fittings and a predetermined space is provided on both sides thereof. This engine mount has an inner cylinder metal fitting attached to either the power plant or the vehicle body.
An outer cylindrical metal fitting is attached to the other side and is used, and the vibration damping effect is mainly achieved by elastic deformation of the rubber elastic body in the shear direction.

By the way, in such an engine mount, the smaller the spring constant of the rubber elastic body, the better in terms of vibration isolation against high-frequency vibrations. but,
Reducing the spring constant poses problems such as rubber fatigue and interference, so we proposed an engine mount that uses a stopper mechanism and has nonlinear characteristics that are soft with small displacements and hard with large displacements. has been done.

Such engine mounts generally include a pair of stopper parts that protrude from the inner surface of the outer cylinder metal fitting into a predetermined space formed on both sides of the inner cylinder metal fitting as described above, and these stopper parts are made of rubber. When a large displacement excitation force is applied, the inner cylindrical fitting contacts directly or indirectly through the rubber layer, suppressing further displacement and obtaining a high spring constant from then on. However, after the stopper portion and the inner cylindrical metal fitting come into contact, the spring constant increases rapidly, which tends to impair the vibration insulation effect.

On the other hand, some proposals have been made in which a cavity is provided inside the stopper part to alleviate the impact upon contact, and the spring constant rises slowly.
In that case, there is a tendency that large displacements cannot be sufficiently suppressed.

In addition, in both of the above two types, the damping of vibrations with large displacements depends on the damping characteristics of the rubber material itself, which naturally imposes restrictions.
There is also the inherent problem that it is difficult to sufficiently obtain the required damping performance.

Purpose of the invention The present invention was developed against the background of the above-mentioned circumstances, and its purpose is to provide a device that is equipped with an outer cylindrical fitting, an inner cylindrical fitting, a rubber elastic body, etc. as described above. To provide an engine mount which can bring spring characteristics as close as possible to required ideal characteristics after a stopper action occurs, and can quickly suppress large displacement between two metal fittings. It is in.

Structure of the invention In order to achieve the above object, in the present invention, from the inner surface of the outer cylindrical fitting or the outer surface of the inner cylindrical fitting,
They protrude into predetermined spaces formed on both sides of the inner cylindrical metal fitting, and the inner cylindrical metal fitting or the outer cylindrical metal fitting protrudes elastically as the inner cylindrical metal fitting and the outer cylindrical metal fitting move relative to each other in the radial direction. A pair of stopper portions made of a rubber material are provided in contact with the stopper portions, and fluid chambers each containing a predetermined incompressible fluid are formed inside the stopper portions, and the fluid chambers are made to communicate with each other. An orifice is provided so that the fluid flows between the fluid chambers through the orifice when the inner cylindrical metal fitting or the outer cylindrical metal fitting and the stopper portion come into contact with each other.

Effects of the invention By doing this, the spring constant becomes higher after the inner cylinder metal fitting or the outer cylinder metal fitting comes into contact with either of the pair of stopper parts, but the extent to which this increases is due to the fact that the stopper parts are all made of rubber. The spring constant is lower than when the stopper part is formed with a cavity, and higher than when a cavity is provided inside the stopper part, and an intermediate rise form of the spring constant is obtained, and an effective vibration isolation effect is obtained while suppressing large displacements. It will be done.

Moreover, when the inner cylinder fitting or the outer cylinder fitting and the stopper part come into contact with each other, the incompressible fluid sealed in the fluid chamber inside the stopper part is made to flow through the orifice, so the viscous resistance This effectively damped vibrations that caused large displacements, making it possible to quickly suppress large movements of the power unit.

Embodiments Hereinafter, embodiments in which the present invention is applied to an engine mount for a front-wheel drive transverse engine vehicle will be described in detail with reference to the drawings.

FIG. 1 schematically shows the front side of such a FF transverse engine vehicle. In this figure, 10 is a power unit, which is an integral combination of an engine and a transmission. And such power unit 1
0 is normally 2 for the center member 12 on the vehicle body side.
It is elastically supported through individual front mounts 14 and rear mounts 16,
In such a FF transverse engine vehicle, the reaction force of the drive system torque acts on the power unit 10 considerably, and there is a strong tendency for the power unit 10 to roll in the direction shown by the arrow when starting, changing gears, etc. The engine mount described below is particularly suitable as the front mount 14 and has a function of effectively suppressing the torque reaction force acting on the power unit 10.

Engine mount (front mount)
14, as shown in FIGS. 2 and 3,
It has a cylindrical inner tube fitting 18, into which the shaft on the power unit 10 side is inserted. A cylindrical outer metal fitting 20 is placed concentrically on the outside of this inner cylinder metal fitting 18 at a predetermined distance apart, and this outer cylinder metal fitting 20 is placed on the vehicle body side (the center member 12
side).

Between the inner cylinder fitting 18 and the outer cylinder fitting 20, a rubber elastic body 22 that elastically connects these metal fittings is arranged so as to surround the inner cylinder fitting 18 and extend in the radial direction of the outer cylinder fitting 20. It is located in
As a result, symmetrical spaces 24, 24 are formed between the inner cylindrical metal fitting 18 and the outer cylindrical metal fitting 20 on both sides of the inner cylindrical metal fitting 18.

On the other hand, from the inner surface of the outer cylindrical metal fitting 20, two stopper parts 26, 26 are provided at symmetrical positions with the inner cylindrical metal fitting 18 in between so as to project into these spaces 24, 24. These stopper portions 26 are made of the same rubber material as the rubber elastic body 22, and are continuous with the connecting portion of the rubber elastic body 22 to the outer cylinder fitting 20 on both sides, and are integrated into an integrated rubber sleeve as a whole. It consists of When the metal fittings 18 and 20 are in a concentric state, a distance between the stoppers 26 and the rubber elastic body 22 surrounding the inner cylindrical metal fitting 18 is maintained. .

Inside these stopper parts 26, each space 24
Two symmetrical recesses 28 are formed so as to extend in the circumferential direction and open on the inner circumferential surface side of the outer cylindrical fitting 20, with the side as the bottom. By being closed by the fluid chamber 3 in each stopper portion 26,
0 is defined, and the fluid chambers 30 thus formed contain predetermined incompressible fluids, respectively.
For example, a suitable fluid such as water, polyalkylene glycol, silicone oil, or a low molecular weight polymer is enclosed.

Note that two relatively thin metal rings 32 sandwich the opening of each recess 28 at both ends in the center line direction of the outer circumferential surfaces of the rubber sleeves 22 and 26 fixed to the outer circumferential surface of the inner cylinder fitting 18. They are provided on each side and are brought into close contact with the inner circumferential surface of the outer cylindrical metal fitting 20 via a thin rubber layer for sealing. These metal rings 32 are embedded by vulcanization adhesive in a place slightly inward from the outer circumferential surface of the rubber sleeve, and the outer cylinder metal fitting 20 is fitted on the outside of the metal ring 32 to restrict the diameter in the direction of reduction. When applied, the compressive force is effectively applied between the inner circumferential surface of the outer cylinder fitting 20 and the outer rubber layer of each metal ring 32,
This is to ensure that the fluid chamber 30 is kept liquid-tight.

Orifices 34, 34 that connect both ends of both fluid chambers 30 in the circumferential direction to each other,
They are formed symmetrically on the outer circumferential surface of the stopper portion 26 so as to extend in an arc shape along the circumferential direction of the outer cylinder fitting 20 . As is clear from FIG. 4, these orifices 34 have circumferential grooves formed across both ends of the stopper portion 26 in the circumferential direction and the connecting portion of the rubber elastic body 22 to the outer cylinder fitting 20. Metal fittings 2
The fluid chambers 30, 30 are formed by being closed with the inner circumferential surface of the fluid chamber 30, thereby allowing both fluid chambers 30, 30 to communicate with each other.

By the way, in order to manufacture such an engine mount 14, for example, one inner cylinder fitting 18 is first manufactured.
and two metal rings 32 are set concentrically in a predetermined mold, and a rubber material is injected between them to form the rubber elastic body 22 and the pair of stopper parts 26.
At the same time, the two spaces 24 and the recess 28 are formed, and the inner cylindrical fitting 18 and the metal ring 32 are vulcanized and bonded. Next, with the thus obtained vulcanized molded product immersed in the fluid tank as described above, the outer cylinder fitting 20 is fitted to the outside of the two metal rings 32, 32, and then the outer cylindrical fitting 20 is The cylindrical metal fitting 20 is drawn in the radial direction and crimped onto the metal ring 32 via a rubber layer. As a result, the fluid is sealed in the fluid chamber 30, and the engine mount 14 as shown in FIGS. 2 to 4 is completed. Note that ribs extending in an annular shape in the circumferential direction are formed in advance on the outer peripheral surface of the outer rubber layer of each metal ring 32, and as the outer cylindrical fitting 20 is drawn, the inner periphery of the ribs is formed in advance. Pressing the surfaces together is effective in improving sealing performance.

Engine mount 14 configured as above
As shown in Figure 1, the horizontal engine FF
It can be suitably used as the front engine mount 14 of a car, and as described above, the inner cylinder fitting 18 is attached to the power unit 10 side, and the outer cylinder fitting 20 is attached to the vehicle body side.

During normal running or idling vibration, the relative displacement between the inner cylinder fitting 18 and the outer cylinder fitting 20 is small, so that the inner cylinder fitting 18 does not come into contact with the stopper parts 26, 26, and the main part of the rubber elastic body 22 In addition, a low dynamic spring constant is obtained due to the shear elastic deformation, and it is possible to effectively prevent idle vibrations and muffled noise of the power unit 10 from being propagated to the vehicle body side.

On the other hand, when the vibration load is large, such as when starting and accelerating, or when an automatic transmission vehicle (AT)
When the vehicle (car) is stopped in the "D range", the power unit 10 receives a reaction force of the drive torque and receives an excitation input so as to tilt backward, causing the inner cylinder fitting 18 and the stopper parts 26, 26 to Stop in between〓
Beyond the range of distance l, the inner cylinder fitting 18 and the outer cylinder fitting 2
0, the inner cylindrical fitting 18 comes into contact with one of the stoppers 26 via the rubber elastic body 22, and from then on, the relative displacement of the inner cylindrical fitting 18 with respect to the outer cylindrical fitting 20 is restrained, 5th
As shown by the solid line in the graph of the figure, the dynamic spring constant rises. At this time, since the incompressible fluid is sealed in the fluid chamber 30 in the stopper part 26, when the stopper part 26 is elastically deformed by the pressing action of the inner cylindrical metal fitting 18, the fluid flows into the orifice 34. , 34 to the fluid chamber 30 on the opposite side.
The vibration damping force is generated by the viscous resistance when flowing through these orifices 34. This damping effect effectively suppresses large displacements of the power unit 10, and so-called wind-up and engine shake can be effectively suppressed.

Since such fluid circulation occurs after the inner cylinder fitting 18 comes into contact with the stopper part 26,
As is clear from the graph in Figure 5, it is not too hard like the conventional all-rubber type in which the stopper part is entirely made of rubber, and it is not too soft like the conventional hollow type in which the stopper part has a cavity inside. It exhibits good nonlinear spring characteristics that are in between these two types.

Furthermore, as shown by the solid line in the graph of FIG. 6, after the inner cylindrical fitting 18 comes into contact with the stopper part 26, the frequency range changes from the low frequency range to the high frequency range, compared to the conventional all-rubber type. The vibration transmission force is kept low, especially in the frequency range just before the damping force of the orifice 34 reaches its peak.
The vibration transmission force is further reduced. Since the level of vibration transmission force is suppressed to a low level in this way, engine transmitted sound can also be effectively prevented, and the vibration and noise characteristics of the power unit 10 can be comprehensively improved.

In addition, the material of the rubber elastic body 22 and the stopper
By appropriately selecting the distance 1, it is possible to generate a damping force due to the viscous resistance of the fluid only in a predetermined input load range.

Furthermore, it goes without saying that the present invention is effective when applied not only to the front engine mount 14 of a transverse engine FF vehicle, but also to the rear engine mount 16, and various modifications may be made based on the knowledge of those skilled in the art. It goes without saying that the present invention can be implemented in a modified form.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing the vicinity of the power unit of a transverse engine FF vehicle to which the present invention is preferably applied. FIG. 2 is a partially cutaway side view of an engine mount that is an embodiment of the present invention.
FIG. 3 is a front view of FIG. 2. Moreover, FIG. 4 is a side view in which the - sectional view in FIG. 3 is partially non-sectional. FIGS. 5 and 6 are graphs showing the spring characteristics of the engine mount according to the present invention in comparison with the conventional one. 10: Power unit, 14: Front mount, 18: Inner cylinder metal fitting, 20: Outer cylinder metal fitting, 22: Rubber elastic body, 24: Space, 26: Stopper part, 3
0: Fluid chamber, 34: Orifice.

Claims (1)

[Scope of Claim for Utility Model Registration] An outer cylindrical metal fitting is placed concentrically on the outside of the inner cylindrical metal fitting at a predetermined distance apart, and the inner cylindrical metal fitting and the outer cylindrical metal fitting are connected via a rubber elastic body, In an engine mount having a structure in which a predetermined space is provided between the metal fittings on both sides of the inner cylinder metal fitting, protruding into each space from the inner surface of the outer cylinder metal fitting or the outer surface of the inner cylinder metal fitting, respectively, A pair of stopper portions made of a rubber material are provided, and the stopper portions are made of a rubber material and come into elastic contact with the inner tube fitting or the outer tube fitting as the inner tube fitting and the outer tube fitting move in a relative radial direction. each forming a fluid chamber in which a predetermined incompressible fluid is sealed, and
An orifice is provided to allow the fluid chambers to communicate with each other, and the fluid flows between the fluid chambers through the orifice when the inner cylindrical metal fitting or the outer cylindrical metal fitting and the stopper portion come into contact with each other. An engine mount characterized by: