JPH05301526A - Suspension device for internal combustion engine - Google Patents

Abstract

PURPOSE:To further reduce the generation of noise and vibration, by which an influence is exercised on the interior of a car, as lateral rigidity provided when an engine is supported to a car body is ensured. CONSTITUTION:An engine 1 is resiliently supported to front side members 5A and 5B and a center member 6 by means of respective mounts 7, 8, 9, and 10. The left and right mounts 9 and 10 are located between the front side members 5A and 5B and the engine 1. The front and rear mounts 7 and 8 are located between the center member 6 and the engine 1. A direction in which a spring constant is increased to a maximum is caused to coincide with a lateral direction LR by means of the front and rear mounts 7 and 8. Thus, rigidity in the lateral direction LR of the left and right mounts 7 and 8 is increased. A burden attributed to total rigidity in the lateral direction LR of the left and right mounts 9 and 10 is relieved, and in the two mounts 9 and 10, the spring constants thereof can be set to a further low value. This constitution causes vibration of the engine 1 to be difficult to propagate to a car body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension system for an internal combustion engine arranged to elastically support the internal combustion engine with respect to a vehicle body.

[0002]

2. Description of the Related Art Conventionally, as a technique of this kind, for example, "Toyota Camry New Model Manual (issued in July 1990)" discloses that an engine is supported on a vehicle body by a plurality of mounts. That is, in this technique, as shown in FIG. 6, the engine 21 is supported by the front mount 22, the rear mount 23, the left mount 24, and the right mount 25 so as to correspond to the front, rear, left, and right directions of the vehicle body. Here, each of the left mount 24 and the right mount 25 is a liquid-filled type insulator 24.
a, 25a. And the left mount 24
In regard to the above, the insulator 24a is arranged so that the direction in which the spring constant is the lowest matches the front-rear direction FR of the vehicle body. The light mount 25 is arranged so that the direction in which the spring constant of the insulator 25a becomes the lowest coincides with the vertical direction UD of the vehicle body.
Further, the front mount 22 and the rear mount 23, which should function as a roll stopper of the engine 21, are provided with cylindrical insulators 22a and 23a made of rubber, respectively. And, those insulators 22a, 2
In 3a, the direction in which the spring constant is the lowest is the left-right direction L of the vehicle body.
It is arranged so as to coincide with R.

[0003]

However, in the above-mentioned conventional technique, the rigidity (horizontal rigidity) of the front mount 22 and the rear mount 23 in the left-right direction LR is small because of the positional relationship. Therefore, for the overall left and right rigidity obtained by all the mounts 22 to 25,
The load on the left mount 24 and the right mount 25 was relatively large. Generally, the left-right rigidity obtained from the mount is necessary to integrate the movement of the vehicle body in the left-right direction LR and the movement of the engine, and it is important to affect the steering stability of the vehicle and the steering feeling. It is one of the adjustment items.

Considering the noise and vibration that affects the interior of the vehicle from the engine 21, the vibration transmitted from the left mount 24 and the right mount 25 to the vehicle body has been a problem due to the structure of the vehicle body. Therefore, in the above configuration in which the left mount 24 and the right mount 25 increase the load on the left and right rigidity, the mounts 24, 2
When it was attempted to further reduce noise and vibration by improving No. 5, it was disadvantageous in terms of achieving both left and right rigidity.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to secure the rigidity in the left-right direction in supporting the internal combustion engine with respect to the vehicle body, while suppressing the noise affecting the vehicle interior. An object of the present invention is to provide a suspension system for an internal combustion engine capable of further reducing vibration.

[0006]

In order to achieve the above object, in the present invention, a front side member and a center member constituting a vehicle body are arranged to elastically support an internal combustion engine, and In a suspension system for an internal combustion engine including a plurality of mounts interposed between the side member and the center member and the internal combustion engine, a direction in which the spring constant of the mount interposed between the center member and the internal combustion engine is highest. Is aligned with the left-right direction of the vehicle body.

[0007]

According to the above construction, the mount having the highest spring constant in the mount interposed between the center member and the internal combustion engine coincides with the left-right direction of the vehicle body. Will grow. Therefore, with respect to the mount interposed between the front side member and the internal combustion engine, the load that should contribute to the total rigidity in the left-right direction obtained from the whole mount is reduced. Therefore, with respect to the mount interposed between the front side member and the internal combustion engine, the spring constant can be set to a further low value, and accordingly, the vibration of the internal combustion engine is less likely to be transmitted to the vehicle body.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the suspension system for an internal combustion engine according to the present invention will be described in detail below with reference to FIGS.

FIG. 1 is a plan view schematically showing the suspension system in this embodiment, and FIG. 2 is a rear view schematically showing the suspension system. An engine 1 as an internal combustion engine is composed of an engine body 2 and a transaxle 3 assembled integrally with the engine body 2. In this embodiment, the engine 1 is arranged horizontally so that the engine 1 is laterally oriented with respect to the vehicle body. 3 and 4 are perspective views showing the vehicle body 4 of the vehicle in this embodiment. The portion shown by the mesh in FIG. 3 is the front side member 5A for supporting the engine 1, and the portion shown by the mesh in FIG. 4 is the center member 6 for supporting the engine 1. The front side members 5A are provided on both the left and right sides of the vehicle body 4, as shown in FIG.
Shows only the right side.

In FIGS. 1 and 2, the engine 1 is elastically supported by a front mount 7, a rear mount 8, a left mount 9 and a right mount 10 which are arranged in the front-rear and left-right directions of the vehicle body 4. A suspension device is configured by these mounts 7 to 10.

The left mount 9 is composed of a cylindrical insulator 9a made of rubber, a bracket 9b and a stay 9c assembled to the insulator 9a, and the like. The left mount 9 is interposed between the left front side member 5B and the transaxle 3 and is connected to each other by a bolt (not shown). The left mount 9 is arranged so that the axial direction S1 in which the insulator 9a has the lowest spring constant matches the front-rear direction FR of the vehicle body 4.

The light mount 10 is composed of a liquid-filled type insulator 10a and a bracket 10b assembled to the insulator 10a. The light mount 10 is interposed between the right front side member 5A and the engine body 2 and is connected to each other by a bolt (not shown). With respect to the light manout 10, the axial direction S2 in which the spring constant is lowest in the insulator 10a is the vertical direction UD of the vehicle body 4.
Are arranged to match. In this embodiment, the two insulators 9a and 10 are used for the purpose of reducing noise and vibration affecting the interior of the vehicle from the engine 1.
The spring constant of a is set low.

On the other hand, the front mount 7 and the rear mount 8 which should perform the roll stop function of the engine 1 are cylindrical insulators 7a and 8a made of rubber, respectively.
And brackets 7b, 8b and the like. Front mount 7 and rear mount 8 are center members 6
And transaxle 3 respectively, and are connected to each other by a bolt (not shown). And
With regard to both mounts 7 and 8, the axial directions S3 and S in which the spring constant is lowest in the respective insulators 7a and 8a.
4 is arranged so as to coincide with the front-rear direction FR of the vehicle body 4. With this arrangement, the direction in which the spring constant is highest in each of the insulators 7a, 8a is arranged so as to coincide with the left-right direction LR of the vehicle body 4.

Further, in this embodiment, the relationship between the positions of the front mount 7 and the rear mount 8 and the spring constant is as follows.
The following well-known restrictions are made. That is, as shown in FIG. 1, the left-right direction LR of the engine 1 with respect to the vehicle body 4
The elastic main axis S0 is arranged so as to coincide with the center of gravity GP of the engine 1. Further, the distance LF from the front mount 7 to the elastic spindle S0 and the rear mount 8 to the elastic spindle S0.
The ratio to the distance LR to 0 is set to be close to "1". Similarly, the spring constant kyF of one insulator 7a and the spring constant ky of the other insulator 8a.
The ratio with R is set to be close to "1".

Next, the operation of the suspension system for an internal combustion engine constructed as described above will be described. First, in this embodiment, the insulators 7a, 8a of the front mount 7 and the rear mount 8 are arranged so that the direction in which the spring constants thereof are highest coincides with the left-right direction LR of the vehicle body 4. Therefore, the rigidity of the front mount 7 and the rear mount 8 in the left-right direction LR becomes high, and the resonance frequency in the left-right direction LR as a suspension device becomes high. Thereby, the behavior of the engine 1 in the left-right direction LR can be suppressed as much as possible. That is, the rigidity of the suspension device in the left-right direction LR can be largely secured by the front mount 7 and the rear mount 8.

Therefore, with respect to the left mount 9 and the right mount 10, the load that should contribute to the overall rigidity in the left-right direction LR obtained by the suspension device is reduced. Therefore, the spring constants of the insulators 9a and 10a can be set to be even lower. In this embodiment, since the spring constants of both the insulators 9a and 10a are set to be low, the vibration generated in the engine 1 is further difficult to be transmitted from the both mounts 9 and 10 to the left and right front side members 5A and 5B. As a result, noise and vibration affecting the interior of the vehicle from the engine 1 can be further reduced.

That is, according to the suspension system of this embodiment,
The front mount 7 and the rear mount 8 can sufficiently secure the rigidity in the left-right direction LR in supporting the engine 1. In addition, the left mount 9 and the right mount 10 can further reduce noise and vibration in the vehicle.

Further, in this embodiment, since the rigidity in the left-right direction LR can be sufficiently ensured as described above, the behavior of the vehicle body 4 in the left-right direction LR and the behavior of the engine 1 at the time of lane change or cornering of the vehicle. And can be integrated. As a result, it is possible to improve the steering stability of the vehicle and thus the steering feeling. That is,
As a suspension device, it is possible to achieve both improved steering stability and reduced noise and vibration.

The steering response characteristics obtained by the suspension system of this embodiment are shown in the graph of FIG. 5 in comparison with those of the conventional example. In this graph, the horizontal axis represents the frequency characteristic of the suspension device, and the vertical axis represents the ratio of the yaw rate corresponding to the index value of steering stability and the steering wheel angle. As is clear from this graph, in the present embodiment, the gain of the ratio between the yaw rate and the steering wheel angle is higher up to the frequency higher than that of the conventional example. Therefore, in the present embodiment, it is understood that the steering stability of the vehicle is improved due to the higher gain.

Further, in this embodiment, the elastic main axis S0 of the engine 1 in the left-right direction LR is arranged so as to coincide with the center of gravity GP of the engine 1. In addition, each distance L from the front mount 7 and the rear mount 8 to the elastic spindle S0
The ratio of F and LR and the ratio of the spring constants kyF and kyR of the respective insulators 7a and 8a in the left-right direction are set to be close to "1", respectively. Therefore, the yaw-direction vibration and the left-right direction vibration of the engine 1 can be decoupled from each other. As a result, as measures against vibration of the engine 1, it is possible to consider separating measures against vibration in the yaw direction and measures against vibration in the left-right direction, which is advantageous in design and adaptation to actual vehicles.

The present invention is not limited to the above-described embodiment, but can be implemented as follows with a part of the configuration appropriately changed without departing from the spirit of the invention. (1) In the above embodiment, the insulator 9a of the left mount 9 is made of rubber, but the insulator 9a can be changed to a liquid-filled type insulator.

(2) In the above embodiment, the horizontal type engine 1 is embodied, but it may be embodied in the vertical type engine 1.

[0023]

As described above in detail, according to the present invention, the center member and the internal combustion engine among the plurality of mounts arranged to elastically support the internal combustion engine with respect to the front side member and the center combustion member. With respect to the mount interposed between the engine and the engine, the direction in which the spring constant is highest is aligned with the left-right direction of the vehicle body. Therefore, the rigidity of the mount in the left-right direction becomes large, and for the mount interposed between the front side member and the internal combustion engine, the load that should contribute to the rigidity in the left-right direction is reduced, and the spring constant is set to a lower value. Thus, it becomes possible to make it difficult for the vibration of the internal combustion engine to be transmitted to the vehicle body. As a result, it is possible to secure the rigidity in the left-right direction when supporting the internal combustion engine with respect to the vehicle body, and at the same time, it is possible to further reduce the noise vibration that affects the inside of the vehicle.

[Brief description of drawings]

FIG. 1 is a plan view schematically showing a suspension system for an internal combustion engine in an embodiment embodying the present invention.

FIG. 2 is a rear view schematically showing the suspension device according to the embodiment.

FIG. 3 is a perspective view showing a vehicle body in one embodiment,
It is a figure which shows especially a front side member.

FIG. 4 is a perspective view showing a vehicle body in one embodiment,
It is a figure which shows a center member especially.

FIG. 5 is a graph showing a steering response characteristic obtained by the suspension device in one example in comparison with that in the conventional example.

FIG. 6 is a perspective view illustrating a configuration of a suspension device in a conventional example.

[Explanation of symbols]

1 ... Engine as internal combustion engine, 4 ... Car body, 5A, 5B
... front side member, 6 ... center member, 7 ... front mount, 8 ... rear mount, 9 ... left mount, 10 ... right mount, S1-S4 ... axial direction, L
R ... Left and right.

Claims (1)

[Claims] 1. A front side member and a center member that form a vehicle body, the elastic member being arranged to elastically support the internal combustion engine, and the intermediate member is interposed between the front side member and the center member and the internal combustion engine. In an internal-combustion-engine suspension system including a plurality of mounts, the mount interposed between the center member and the internal combustion engine is arranged such that the direction in which the spring constant is highest coincides with the left-right direction of the vehicle body. A suspension device for an internal combustion engine characterized by the above.