JP2002274196A - Device for supporting power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for supporting a power unit capable of easily setting roll rigidity and pitching rigidity in a well-balanced way in a transversely installed rear engine bus. SOLUTION: A power unit 1 of the transversely installed rear engine bus is equipped with a transverse 5 for converting and transferring power of an engine 2 to a front part of a vehicle. Elastic support members 6, 7 are mounted on side parts in the longitudinal direction of the vertical respectively at a front part of the engine 2 and a rear part of a transmission 3 which are spaced in the car width direction and an elastic support member 10 is mounted below the vicinity of gravity center of the unit 1 between the members 6, 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for elastically supporting a power unit in which an engine, a transmission, and the like are integrally connected, in a rear-mounted rear engine bus.

[0002]

2. Description of the Related Art As illustrated in FIGS.
A power unit 1 of a bus in which the center axis of the engine is disposed at the rear portion of the vehicle in a vehicle width direction, that is, a so-called horizontal rear engine bus, has an engine 2 and a transmission 3 integrally connected and a transmission. A transverse 5 is provided to convert the power of the engine 2 to the front of the vehicle via the device 4 and transmit the power. The roll 5 has a roll vibrating force indicated by an arrow A that acts on the power unit 1 itself around the crankshaft of the engine 2. Transverse 5 when connecting the clutch
It is necessary to provide an anti-vibration device against both the pitching vibrating force of the arrow B acting on the power unit 1 itself with the output shaft extending forward from the vehicle as the center. Reference numeral 8 denotes a chain transfer in the transmission 4.

For this reason, conventionally, elastic support members 6 and 7 of the power unit 1 are provided at the front part of the engine 2 and the rear part of the transmission 3 which are separated from each other in the vehicle width direction, respectively, in the vehicle longitudinal direction. The elastic support member 6
7, the roll resonance frequency of the power unit 1 is set lower than the primary frequency of the engine explosion, which is the main component of the roll vibrating force when the engine 2 is at the minimum rotation speed.
However, if the roll resonance frequency is too low, that is, if the spring constants of the elastic support members 6 and 7 are too small, the rotational fluctuation rate of the engine 2 becomes particularly large. Since the displacement of the power unit 1 due to vibration becomes excessive at the time of starting the engine 2, the design value of the roll rigidity of the elastic support members 6, 7 with respect to the power unit 1 is determined from these balances.

On the other hand, the pitching stiffness of the elastic support members 6 and 7 with respect to the power unit 1 also needs to be designed in the same way as in the case of the roll stiffness described above. , Kr, and the distance in the vehicle width direction from the center of gravity G of the power unit 1 to the elastic support members 6 and 7 is Lf and Lr, respectively, the pitching rigidity becomes [Kf · Lf · Lf + Kr · Lr · Lr]. , Lf and Lr are relatively large, and the pitching rigidity may be excessive.
7, the spring constants Kf and Kr need to be designed low.

However, if the elastic constants Kf and Kr of the elastic support members 6 and 7 are low, the roll stiffness may be too small, so that it is practically difficult to design a good balance between the roll stiffness and the pitching stiffness. In addition, there is a problem that the load of the power unit 1 acting on the elastic support members 6 and 7 becomes excessive, and the durability of the mount rubber in the elastic support members 6 and 7 is impaired.

If the above-mentioned distances Lf and Lr in the vehicle width direction can be freely selected when the power unit 1 is mounted on the bus, the above problem can be suppressed. For this reason, it is actually difficult to freely select the horizontal distances Lf and Lr in the vehicle width direction.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a power unit supporting apparatus which can easily set the roll rigidity and the pitching rigidity in a horizontal rear engine bus in a well-balanced manner.

[0008]

Therefore, in the power unit supporting device according to the present invention, the output shaft of the laterally mounted rear engine bus is spaced apart from the power unit extending forward in the vehicle width direction. At the same time, an elastic support member is installed on each side in the vehicle front-rear direction, and an elastic support member is installed below the vicinity of the center of gravity of the power unit located between the elastic support members separated in the vehicle width direction.

That is, since the latter elastic support member is installed below the vicinity of the center of gravity of the power unit and can share the load of the power unit, the load of the power unit on the former elastic support member is reduced by the latter elastic support member. Since the support member is lessened than when it is not installed, even if the former elastic support member is designed to have a relatively low spring constant and the pitching rigidity for the power unit is appropriately large, Impairing the durability of the elastic support member can be suppressed, and the distance between the center of gravity of the power unit and the latter elastic support member in the vehicle width direction is small.
Since the effect of the latter elastic support member on the pitching rigidity is small, the design relating to the pitching rigidity is easy, and by appropriately setting the magnitude of the shear spring constant in the vehicle longitudinal direction in the latter elastic support member,
Since the magnitude of the roll rigidity with respect to the power unit can be adjusted, the design relating to the roll rigidity is also facilitated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described by assigning the same reference numerals to the same parts as those of the conventional device. In FIGS. 1 and 2, a power unit 1 of a horizontal rear engine bus has an engine 2 and a transmission 3 integrally connected thereto, and converts power of the engine 2 through a transmission device 4 and transmits the power to the front of the vehicle. A transversal 5 is provided, and elastic support members 6 and 7 of the power unit 1 are installed at the front part of the engine 2 and the rear part of the transmission 3 which are separated from each other in the vehicle width direction, respectively, at the side part in the vehicle front-rear direction. And a power unit 1 located between the elastic support members 6 and 7 apart in the vehicle width direction.
The elastic support member 10 of the power unit 1 is installed below the vicinity of the center of gravity G.

In this case, the load of the power unit 1 is borne by the elastic support members 6 and 7 and the elastic support member 10, and the power unit 1 acting on the elastic support members 6 and 7 by the shared load of the elastic support member 10. Therefore, even if the spring constant of the elastic support members 6 and 7 is designed to be relatively low so that the pitching rigidity with respect to the power unit 1 is not excessive, the durability of the elastic support members 6 and 7 can be improved. Damage has the advantage that it can be effectively suppressed.

Further, since the distance Lc between the center of gravity G of the power unit 1 and the elastic support member 10 in the vehicle width direction is small, the effect of the elastic support member 10 on the pitching rigidity is small. The design is easy from this point as well, and the roll spring rigidity with respect to the power unit 1 is adjusted by setting the shear spring constant of the elastic support member 10 in the longitudinal direction of the vehicle to an appropriate magnitude, thereby adjusting the roll rigidity. The design relating to the rigidity is also facilitated, and the magnitudes of the shear spring constant in the vehicle longitudinal direction and the spring constant in the expansion and contraction direction of the elastic support member 10 can be set separately. Because the change can be small,
The roll stiffness and the pitching stiffness can be relatively easily designed to a well-balanced optimum value to realize an elastic support device for the power unit 1 having high vibration isolation performance. Can be effectively suppressed, and the riding comfort of the bus can be improved.

[0013]

In the power unit supporting apparatus according to the present invention, the elastic support members of the power unit are also provided below the vicinity of the center of gravity of the power unit, so that the power unit can attach to each elastic support member. Since the load can be reduced, the durability of each elastic support member can be reliably increased, and the pitching rigidity and the roll rigidity for the power unit can be easily set in a well-balanced manner. At
An elastic support device for a power unit having high vibration isolation performance can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic front view of an embodiment of the present invention.

FIG. 2 is a side view of the embodiment.

FIG. 3 is a schematic front view of a conventional device.

FIG. 4 is a side view of the conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power unit 2 Engine 3 Transmission 5 Transverse 6, 7, 10 Elastic support member

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shinji Yamaguchi 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation F-term (reference) 3D035 CA01 CA19 CA25 CA26 3J048 AA01 BA01 BC01 DA03 EA07

Claims (1)

[Claims] In a laterally mounted rear engine bus, an elastic support member is provided on a side of a power unit having an output shaft extending forward of a vehicle, which is spaced apart from each other in a vehicle width direction and on a side in a vehicle front-rear direction. A power unit supporting device in which an elastic supporting member is installed below a vicinity of a center of gravity of the power unit located between the elastic supporting members separated in a vehicle width direction.