JPS63145124A - Power unit supporting structure for automobile - Google Patents

Abstract

PURPOSE:To make the flexibility quantity of a mount largely securable in a direction of positive load, by making negative load act on this mount with dead weight of a power unit. CONSTITUTION:A power unit 4 is supported by first and second rubber mounts 5 and 6 to be set up in a distant position, in a direction of a crankshaft or an output shaft of this power unit 4, and a third rubber mount 7 to be set up as offset in a width direction of the power unit 4 in relation to the crankshaft. Therefore, negative load comes to act on the third mount by dead weight of the power unit in consequence, so that a spring constant of the third mount can be softly set in a wide range, thus a vibration reduction at the tie of power increment at acceleration or the like is promotable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a power unit support structure for an automobile.

(Prior Art) A power unit consisting of an engine body, a transmission, etc. is usually attached to a vehicle body via three rubber mounts (see, for example, Japanese Patent Laid-Open No. 79023/1983).

However, in such a support structure, since the center of gravity of the power unit is located within the triangle connecting the three mounts, all the mounts are subjected to positive loads and become stiff, and when the output increases during acceleration etc. It cannot bend much,
It cannot sufficiently contribute to reducing the shock (vibration).

The present invention has been made in view of the above problems, and an object of the present invention is to provide a power unit support structure for an automobile that reduces shocks such as vibrations that occur when output increases such as during acceleration.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a power unit with a first
and a structure in which the power unit is supported by a second mount and a third mount offset in the width direction of the power unit with respect to the output shaft, the center of gravity of the power unit being located at the center of gravity of the first and second mounts. is offset to the opposite side from the third mount with respect to the line connecting the mounts.

(Function) A negative load acts on the third mount due to the weight of the power unit, and it is possible to ensure a large amount of deflection of the third mount in the direction of the positive load.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

Figures 1 and 2 show the power unit support structure of an automobile.
In the figure, 1 is an engine body, 2 is a transmission, and 3 is an intake manifold, which constitute a power unit 4.

The power unit 4 has three rubber mounts)-5,
It is elastically supported by 6 and 7. That is, in the direction of the crankshaft which is the output shaft of the power unit 4,
The first and second rubber mounts 5 and 6 are arranged at separate positions, and the power unit 4 is connected to the crankshaft.
It is supported by a third rubber mount 7 which is arranged offset in the width direction.

Since the crankshaft is rotating in the direction A in FIG. 2, the third rubber mount 7 is located on the side receiving the driving reaction force.

The center of gravity G of the power unit 4 is offset to the opposite side from the third rubber mount 7 with respect to the line Ω connecting the first and second rubber mounts 5 and 6, and the third rubber mount 7 is It is designed to receive a normal load.

The first and second rubber mounts 5 and 6 are attached to a front side frame (not shown) via a support bracket 10.11, and the third rubber mount 7 is attached to a subframe 12 that is attached and fixed to the vehicle body. Connection is fixed.

Further, on the opposite side of the third rubber mount 7, a fourth rubber mount 13, which functions as a stopper when a large displacement occurs, is interposed between the engine main body 1 and the subframe 12, and stops them. It is connected. The amount of deflection of the fourth rubber mount 13 is zero under normal conditions.

With the above configuration, a drive reaction force is generated in the direction B opposite to the rotation direction A of the crankshaft, which is the output shaft of the engine body 1, and the third rubber mount 7 on which the drive reaction force acts is originally in an extended state due to a negative load acting on it, so even if the output increases during acceleration, for example, the load acting on the third rubber mount 7 will go from zero to a positive load due to the action of the driving reaction force. When there is a large change in the output power, the third rubber mount 7 is correspondingly deflected to a large extent and becomes compressed, effectively mitigating the shock of the increase in output.

In other words, as shown in Figure 3, a negative load is applied in the initial state P1, so even if the load changes to a positive one due to an increase in output, the amount of deflection will also change significantly. (See arrow U).

Vibration reduction, etc. can be achieved. That is, the spring constant of the third rubber mount 7 can be set to be soft over a wide range.

(Effects of the Invention) Since the present invention is configured as described above, a negative load acts on the third mount due to the weight of the power unit, and it is possible to set the spring constant of the third mount to be soft over a wide range. This reduces vibration when the output increases, such as during acceleration.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a schematic plan view showing a power unit support structure of an automobile, FIG. 2 is a schematic front view of the same, and FIG. 3 is a diagram showing the amount of deflection of the third rubber mount. It is a graph showing the relationship with load. 1... Engine body, 2... Transmission, 4... Power unit, 5, 6.
7...Rubber mount, G...Center of gravity.

Claims (1)

[Claims] (1) The power unit is configured by the first and second mounts, which are arranged at positions separated from each other in the direction of the output shaft of the power unit, and the third mount, which is arranged offset in the width direction of the power unit with respect to the output shaft. A power unit support structure for an automobile, wherein the position of the center of gravity of the power unit is offset to the opposite side from the third mount with respect to a line connecting the first and second mounts. .