JPH03273930A - Engine unit suspension device for vehicle - Google Patents

Abstract

PURPOSE:To improve vibration-proof characteristics for idling vibration advantageously by using an engine amount in which low rigidity is set in the torsional direction and in pinch direction due to a spherical slide mechanism and mounting its shaft core approximately in parallel with the inertia main shaft of an engine unit. CONSTITUTION:An engine unit 10 is connected with a car body frame 12 via a pair of engine mounts 14, 14 which are mounted on both sides of an inertia main shaft 16 which stretches in the arrangement direction of its cylinder. The engine mount 14 connects an inner cylindrical metal fixture 18 to an outer cylindrical metal fixture 20 which are arranged apart by the predetermined distance in radial direction by means of a rubber elastic body 22 which exists between them to constitute the so-called cylindrical mount structure. A race metal fixture 26 which has spherical recessed face which faces to the spherical projected face of a spherical projected section 24 on the inside peripheral face is provided coaxially on the outside of the inner cylindrical metal fixture 18. Further, a ring-shaped slide member 28 is interposed between spherical projected face of the spherical projected section 24 of the inner cylindrical metal fixture 18 and spherical recessed face of the race metal fixture 26.

Description

Detailed Description of the Invention (Technical Field) The present invention provides vibration-proof support for an engine unit in a vehicle such as an automobile in a suspended state on the vehicle body side by engine mounts arranged on both sides of the main axis of inertia. The present invention relates to an inertial main shaft suspension system for a vehicle engine unit.

(Background Art) Conventionally, as a type of suspension system for the engine unit of a vehicle such as an automobile, engine mounts for supporting the engine unit toward the vehicle body are mounted on both sides of the main axis of inertia of the engine unit. A so-called inertial main shaft suspension system is known, which is configured to support the engine unit in a suspended state relative to the vehicle body by mainly supporting the weight of the engine unit using an engine mount. Mainly FF (front engine/front drive)
As a suspension system for engine units in type automobiles,
It has been suitably used.

In addition, in this type of suspension system, the engine mount usually includes an inner cylinder metal fitting and an outer cylinder metal fitting arranged at a predetermined distance in the radial direction, and a rubber elastic body interposed between them. A so-called cylindrical mount, which is connected to each other, is used, and such a cylindrical mount is interposed between the engine unit and the vehicle body, with the mount axis perpendicular to the main axis of inertia of the engine unit. It is said that the structure is as follows.

However, in such an inertial main shaft suspension system, the engine unit is connected to the vehicle body through an engine mount at the upper part and is supported in a suspended state. The center of gravity of the engine is located vertically below the main axis of inertia, which is the support axis, and the engine unit tends to swing about the main axis of inertia, and the natural vibration frequency of the engine unit is relatively low. Because it occurs in a low frequency range,
If the spring constant of the engine mount is tuned appropriately, taking into account the damping performance against low-frequency vibration input in the vertical direction such as shaking and the durability of the mount, the natural vibration frequency of the engine unit will be the frequency of idling vibration. (usually around 20Hz in a 4-cylinder engine).

Therefore, when inputting idling vibration,
This had a major problem: the vibration displacement of the engine unit increased, making it difficult to achieve an effective vibration damping effect.

(Solution Section B) Here, the present invention has been made against the background of the above-mentioned circumstances, and the problems to be solved are:
An improved engine unit suspension system for a vehicle that can advantageously improve vibration isolation characteristics against idling vibration without significantly deteriorating the damping performance against low frequency vibrations input in the vertical direction such as shaking or the durability of the mount. Our goal is to provide the following.

(Solution Means) In order to solve this problem, the present invention suspends the vehicle engine unit from the vehicle body through engine mounts attached to both sides of the main axis of inertia. In a vehicle engine unit suspension system with anti-vibration support provided below, an annular slide having a spherical concave portion corresponding to the spherical convex portion is provided on the outside of an inner cylinder metal fitting having a spherical convex portion on the outer circumferential surface of an axially intermediate portion. A sliding member is disposed, and the spherical protrusion and the spherical recess are fitted in a spherical slidable manner, and an outer cylindrical fitting is disposed radially outward of the sliding member at a predetermined distance. A cylindrical mount in which a sliding member and the outer cylindrical metal fitting are connected by a rubber elastic body interposed between them is used as the engine mount, and the inner cylindrical metal fitting and the outer cylindrical metal fitting in the cylindrical mount are used. is attached to either the engine unit or the vehicle body so that their axes are substantially parallel to the main axis of inertia of the engine unit;
This is its characteristic.

(Operations/Effects) In other words, the vehicle engine unit suspension system according to the present invention uses an engine mount whose rigidity in the torsional direction and the prying direction with respect to the mount axis is set to be low by the spherical sliding mechanism, and By mounting the engine unit so that the spring is approximately parallel to the main axis of inertia of the engine unit, the spring constant around the main axis of inertia in the support spring system of the engine unit suspension system is
It can be reduced very advantageously.

As a result, the natural vibration frequency of the engine unit is shifted to a lower frequency side, and resonance due to idling vibration can be avoided, and the vibration isolation performance against such idling vibration can be effectively improved. It will become.

In addition, the engine unit used in the vehicle engine unit suspension W that bends has a spherical sliding mechanism that reduces the rigidity in the torsional direction and the prying direction with respect to the mount axis, Although a sufficient spring constant in the direction perpendicular to the mount axis can be ensured, there is a possibility that the mount durability or the damping performance against vertically input low-frequency vibrations such as shakes in the suspension system will be significantly reduced. There is no such thing.

(Example) Hereinafter, in order to clarify the present invention more specifically, an example of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 show schematic diagrams of an automobile engine unit suspension system in an FFItW type engine constructed according to the present invention. Note that in FIGS. 1 and 2, the left-right direction on the drawings is the vehicle left-right direction, and in FIG. 1, the up-down direction on the drawings is the vertical up-down direction, and in FIG. , the vertical direction in the drawing is the vehicle longitudinal direction.

In these figures, 10 is an engine unit including an engine body and a transmission, and 12 is a vehicle body frame. Such an engine unit 10 is
The engine unit is placed horizontally in the engine room of a vehicle with the cylinder arrangement direction, in other words, the longitudinal direction of the crankshaft in the engine unit, being in the vehicle lateral direction. The engine unit IO is connected to the vehicle body frame 12 via a pair of engine mounts 14.14 mounted on both sides of the main shaft of inertia 16 extending in the direction in which the cylinders are arranged. 12, and is supported in a suspended state in a vibration-proof manner.

In addition, in such a suspension system, the weight of the engine unit 10 is mainly supported via the engine mount 14.14, while the weight of the engine unit 10 is usually supported via the main axis of inertia 16 of the engine unit 10, although not shown. The lower portions of both sides of the engine unit 10 are connected to the vehicle body frame 12 via roll mounts.
The displacement in the roll direction will be regulated.

Therefore, in the engine mount 14,
As shown in FIGS. 3 and 4, an inner cylindrical fitting 18 and an outer cylindrical fitting 20 are arranged at a predetermined distance in the radial direction.
They are connected by a rubber elastic body 22 interposed between them, and have a so-called cylindrical mount structure.

More specifically, the inner cylindrical fitting 18 has a thick-walled cylindrical shape as a whole, and has a spherical convex portion 24 having a spherical outer circumferential surface convex radially outward in its axially central portion. , are integrated.

Further, on the outside of the inner cylindrical fitting 18, a race fitting 26 having a substantially cylindrical shape and having a spherical concave surface corresponding to the spherical convex surface of the spherical convex portion 24 on its inner peripheral surface is concentrically arranged.

Further, an annular sliding member 28 made of a predetermined resin material is interposed between the spherical convex surface of the spherical convex portion 24 of the inner cylinder fitting 18 and the spherical concave surface of the race fitting 26. The sliding member 28 has an outer peripheral surface that is connected to the race fitting 26.
is fixed to the spherical concave surface of the inner cylindrical fitting 18, while its inner circumferential surface is positioned with a slight clearance to the spherical convex portion 24 of the inner cylindrical fitting 18. This constitutes a spherical recess that allows the spherical convex portion 24 to be held in a spherical slidable manner.

In addition, in such a sliding member 28, for example, when the race metal fitting 26 is placed outside the inner cylinder metal fitting 18, the annular space formed between the hook metal fittings 26 and 18 is removed. By filling the space with a predetermined resin material, the space can be formed directly within the space. That is, by forming the sliding member 28 directly in the annular space in this way, the inner circumferential surface of the sliding member 28 and the spherical convexity of the inner cylinder fitting 18 are formed based on the shrinkage effect when the resin hardens. A slight clearance can be advantageously formed between the outer circumferential surface of the portion 24 and a shape that is faithful to the outer circumferential surface of the spherical convex portion 24.

Further, the outer cylinder fitting 20 is arranged on the radially outer side of the race fitting 26 at a predetermined distance. The rubber elastic body 22, which has a substantially thick-walled cylindrical shape as a whole, is interposed between the race fitting 26 and the outer cylindrical fitting 20, and its inner circumferential surface is in contact with the outer circumferential surface of the race fitting 26. Then, the outer circumferential surface is relative to the inner circumferential surface of the outer cylinder fitting 20,
By vulcanizing and adhering them, the race fitting 26 and the outer cylinder fitting 20 are elastically connected by the rubber elastic body 22.

The outer cylindrical fitting 20 is positioned eccentrically by a predetermined dimension in the radial direction with respect to the inner cylindrical fitting 18 and the race fitting 26, and the engine unit 10 is mounted on the vehicle as described above. The rubber elastic body 22 is elastically deformed by the weight of the rubber elastic body 22, so that the rubber elastic body 22 is positioned substantially concentrically. In addition, an outer cylinder fitting 20 is attached to the rubber elastic body 22 with a race fitting 26 sandwiched therebetween.
Thickened portions 30 and 32 that penetrate in the axial direction are provided at positions located on both sides of the engine unit in the eccentric direction, and the spring characteristics in the radial direction are tuned, and the engine unit The generation of tensile stress due to weight can be reduced.

That is, the engine mount 1 having such a structure
4, the spherical sliding mechanism formed between the inner cylindrical fitting 18 and the sliding member 28 allows the outer cylindrical fitting 20 of the inner cylindrical fitting 18 to be moved without impairing the spring characteristics in the direction perpendicular to the mount axis. Displacement in the torsional direction about the axis and displacement in the twisting direction inclined with respect to the axis can both be tolerated with low rigidity.

As shown in FIGS. 1 and 2, the engine mount 14 has an inner tube fitting 18 attached to the engine unit 10, and an outer tube fitting 20 attached to the vehicle body frame 12, respectively. By being attached, the mount axis is aligned with the main axis of inertia 1 of the engine unit 10.
The engine unit 10 is interposed between the engine unit 10 and the vehicle body frame 12 so as to be substantially parallel to the engine unit 6.

Therefore, in the vehicle engine unit suspension system as described above, the spring constant of the support spring system for the engine unit around the main shaft of inertia 16 as the support shaft of the engine unit 10 is arranged on both sides of the main shaft of inertia 16. Based on the low rigidity displacement allowed between the inner and outer cylindrical fittings 18 and 20 of each engine mount 14 in the torsional and prying directions with respect to the mount axis, the rigidity can be effectively reduced. The natural vibration frequency around the principal axis of inertia 16 can be advantageously shifted to a lower frequency range.

As a result, the natural vibration frequency of the engine unit 10 can be sufficiently separated from the frequency range corresponding to idling vibration, and the vibration isolation characteristics against idling vibration can be improved extremely effectively. can be achieved.

Moreover, in the engine mount 14 used in the suspension system of such an engine unit,
When the rigidity decreases in the torsional and prying directions with respect to the mount axis, it is not accompanied by a decrease in the spring constant in the direction perpendicular to the mount axis, so the durability of the engine mount 14 can be advantageously ensured, and the rigidity is reduced when the vehicle is running. The damping characteristics against low frequency vibrations such as shake can also be effectively exhibited.

Although one embodiment of the present invention has been described in detail above, this is a literal illustration, and the present invention is not to be construed as being limited only to this specific example.

For example, the specific structure of the sliding mechanism of the inner cylinder metal fitting in the engine mount employed in the vehicle engine unit suspension system according to the present invention is not limited in any way.

Specifically, in the embodiment described above, the sliding member 28 was made of a synthetic resin material and was reinforced and supported by the race fittings 26. The member may be directly fixed to the rubber elastic body 22.

The material of the sliding member 28 is not limited in any way, and may include various resins such as nylon, acetal, phenol, etc., resins mixed with reinforcing fibers, or oil-impregnated resins. Furthermore, it is also possible to form such a sliding member 28 from a metal material.

Furthermore, in the present invention, the engine mount is provided with a fluid chamber in which a predetermined incompressible fluid is sealed, and input vibration is damped based on the flow action or resonance action of the sealed fluid. It is also possible to employ a so-called fluid-filled mounting device.

In addition, although the above-mentioned embodiment shows an example in which the present invention is applied to an engine unit suspension system for a front-wheel drive vehicle, the present invention can also be applied to engine unit suspension systems for various other types of vehicles. Of course, it can also be applied in the same way.

In addition, although not listed, the present invention can be implemented in embodiments with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art, and such embodiments may be different from the present invention. It goes without saying that any of these are included within the scope of the present invention as long as they do not depart from the gist of the invention.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing a specific example of a vehicle engine unit suspension system constructed according to the present invention, and FIG. 2 is a schematic plan view of such a vehicle engine unit suspension system. Further, FIG. 3 is a longitudinal sectional view showing the engine mount used in the vehicle engine unit suspension system shown in FIG. 1, and FIG.
It is a sectional view taken along IV-IV in the figure.

Claims (1)

[Scope of Claims] A vehicle engine unit suspension system in which a vehicle engine unit is supported in a vibration-proof manner in a suspended state on a vehicle body through engine mounts mounted on both sides of the main axis of inertia. , an annular sliding member having a spherical concave portion corresponding to the spherical convex portion is disposed on the outside of the inner cylindrical metal fitting having a spherical convex portion on the outer peripheral surface of the axially intermediate portion, and the spherical convex portion and the spherical concave portion are connected to each other. are fitted in a spherical slidable manner, and an outer cylindrical fitting is arranged radially outward of the sliding member at a predetermined distance, and the sliding member and the outer cylindrical fitting are connected between them. A cylindrical mount connected by an interposed rubber elastic body is used as the engine mount, and an inner cylindrical metal fitting and an outer cylindrical metal fitting of the cylindrical mount are attached to each of the engine unit and the vehicle body. A vehicle engine unit suspension system, characterized in that the engine unit suspension system is mounted so that their axes are substantially parallel to the main axis of inertia of the engine unit.