JPH02200521A - Power unit support device for automobile - Google Patents

Abstract

PURPOSE:To reduce noise in a car by providing a mounting member by which an engine transmission connecting member and a car body are elastically connected together at the point in front of the center of gravity of a power unit. CONSTITUTION:An engine transmission connecting member 6 that has an roughly U-shaped cross section is arranged so as to place its end part in front of the center of gravity of a power unit, and in front of the center of gravity, a reinforcement member 8 that is rigidly fastened to the engine transmission connecting member 6 is connected with the side of a car body 13 through an elastic member 11. Even if secondary bending vibration of engine rotation is caused by the power unit, since vibration energy is converted into heat energy in the elastic member 11 in the process of transmitting the vibration to the side of the car body 13, the bending vibration of the power unit is not practically transmitted to the car body 13. Noise in a car due to bending vibration caused by power unit can thus be effectively reduced.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a power unit support device for an automobile, and particularly relates to an engine mount that can improve the connection rigidity of an engine-transmission connection member. be.

[Prior Art] Generally, in a horizontally mounted power unit in which the engine and transmission are arranged longitudinally in the width direction of the vehicle, the engine and transmission are arranged in a direction perpendicular to the axial direction of the crankshaft of the power unit (in the vertical direction or Longitudinal direction)
Bending vibrations causing displacement are induced, and when such vibrations of the power unit are transmitted to the vehicle body, noise (muffled sound) is generated inside the vehicle. Therefore, for example, as shown in Figure 5,
When viewed in the axial direction of the torque roll g', the power unit P
Mount members 101 and 102 are arranged at both ends of the power unit P to suppress the displacement thereof and to block transmission of vibrations from the power unit P to the vehicle body (see, for example, Japanese Utility Model Application No. 123421/1983). A mount member 103 is also provided on the side near the center of gravity G'.

However, with this mounting method, engine rotation 1
Although the next vertical bending vibration can be reduced, as shown in Figure 4, the vertical excitation force Q due to the secondary engine rotation acts on approximately the center of the crankshaft (crank center).
There is a problem in that the bending vibrations caused by this cannot be sufficiently reduced, and such vibrations become especially severe when the connection rigidity between the engine and the transmission is low.

Therefore, a power unit has been proposed in which an engine-transmission coupling member having a substantially U-shaped cross section and fastened to the engine and transmission is provided to increase the coupling rigidity of the coupling portion between the engine and the transmission (for example, (See Utility Model Application Publication No. 58-129040).

[Problems to be Solved by the Invention] However, in the above-mentioned conventional engine-transmission connection member having a substantially U-shaped cross section, the front end opening has low rigidity in the direction perpendicular to the axis of the crankshaft.
There is a problem in that vibrations are generated as if opening and closing in this direction, that is, as if the opening were opening and closing, and the rigidity of the connection between the engine and the transmission could not be sufficiently increased.

The present invention has been made in view of the above-mentioned conventional problems, and is designed to sufficiently increase the rigidity of the connection between the engine and the transmission, and to prevent not only the primary bending vibration of the engine rotation but also the secondary vibration of the engine rotation acting on the crank center. It is an object of the present invention to provide a power unit support device for an automobile that can effectively reduce bending vibration caused by excitation force and reduce noise inside a vehicle.

[Means for Solving the Problems] In order to achieve the above object, the present invention is provided with mounting members at both ends in the axial direction of the torque roll shaft, and mounted horizontally on a vehicle so that the axial direction is the axle direction. In a power unit consisting of a transmission with a differential gear and an engine, the engine transmission is disposed below the engine and has a substantially U-shaped cross section with a distal end disposed in front of the center of gravity of the power unit when viewed in the axial direction of the crankshaft. Provided is a power unit support device for an automobile, characterized in that a connecting member is provided, and a mount portion is provided for elastically connecting the engine/transmission connecting member to the vehicle body at a position forward of the center of gravity.

[Operations and Effects of the Invention] Generally, the vertical bending vibration induced in the power unit by the secondary excitation force of the engine rotation acting on the crank center is caused by the vibration in the axial direction of the crankshaft from the center of gravity of the power unit, as shown in Fig. 4. The front side is strong.

According to the present invention, the engine-transmission connecting member having a substantially U-shaped cross section is disposed such that its tip is located forward of the center of gravity, and the engine-transmission connecting member has a substantially U-shaped cross section. The transmission connecting member is elastically mounted on the vehicle body by the mount portion.

For this reason, the distal end opening of the engine-transmission connecting member is prevented from displacing by the mount.
The rigidity of the tip opening in the opening/closing direction is increased, which increases the rigidity of the connection between the engine and the transmission, and reduces not only the primary bending vibration but also the secondary vertical vibration of the engine rotation that acts on the crank center. It is also possible to effectively reduce the bending vibration caused by the bending vibration, thereby reducing in-vehicle noise (muffled sound).

[Example code] Examples of the present invention will be specifically described below.

As shown in Figure 3, the horizontally mounted power unit PU
is equipped with a 4-cylinder engine E having first to fourth cylinders #1 to #4 arranged substantially in series in the width direction of the vehicle, a differential gear (not shown), and an input shaft and an output shaft. and a transmission T consisting of a gear train (not shown) attached to the transmission T. Then, when looking in the longitudinal direction of the power unit 14'U, the engine E
The transmission T of the cylinder block L that constitutes the
Although not shown, the end face of the transmission T and the end face of the transmission T on the engine E side are connected by a common method using a fastening bolt or the like.

The power unit PU is formed with a torque roll shaft C extending in the axial direction of the crankshaft (see FIG. 1), the output shaft (not shown) of the transmission T, and the like. A first-order vertical bending vibration is induced in the power unit PU with respect to the torque roll axis e at a certain engine speed. In order to suppress this primary vertical bending vibration, the front end (engine side end) and rear end (transmission side end) of the power unit P are are the first. Second mount members 3, 4 are provided. Further, a third mount member 5 is provided on the side of the center of gravity G of the power unit PU. Note that each of these mount members 3 to 5 is a normal mount member provided with a suitable elastic member, so a detailed explanation thereof will be omitted. and,
The first to third mounts i[43 to 5 effectively suppress primary vertical bending vibrations induced in the power unit PU.

As mentioned above, the cylinder block L and the transmission T are connected by ordinary bolt fastening, but since sufficient connection rigidity cannot be obtained with this connection method, in order to increase this connection rigidity, a roughly U-shaped An engine-transmission connecting member 6 having a shaped cross section is arranged along the outer IM of the oil pan 7 with a slight distance therebetween. The engine-transmission coupling member 6 is fastened from the side of the engine E to the side surface of the cylinder block 1 by fixing bolts 9, and is fastened to the front end surface of the transmission T by suitable fastening means (not shown). There is. This engine
The transmission connecting member 6 increases the rigidity of the connection between the engine E and the transmission T, and in particular suppresses vertical bending vibration of the primary rotation of the engine.

As shown in FIGS. 1 and 2, near the front end of the engine-transmission coupling member 6, it is disposed in close contact with the engine-transmission coupling member 6 over almost the entire outer circumferential surface of the engine-transmission coupling member 6. An upper plate 8a, a substantially crescent-shaped vertical plate 8b formed continuously with the upper plate 8a and having a wide center portion in the width direction of the engine E, and a vertical plate 8b continuous with the upper plate 8b. A reinforcing member 8 is provided along the lower edge of the reinforcing member 8 and a lower plate 8c. This reinforcing member 8 is attached to the engine-transmission coupling member 6 by attachment bolts 10 near the upper ends of both sides thereof. Since the reinforcing member 8 has a U-shaped longitudinal section, its rigidity in the direction perpendicular to the axis of the crankshaft, that is, in the direction in which the opening of the engine-transmission connecting member 6 extends, is extremely high. Since the engine-transmission connecting member 6 is tightly bolted into the reinforcing member 8, its opening cannot be displaced in the opening/closing direction, thus greatly increasing the rigidity of the engine-transmission connecting member 6. It will be done.

The reinforcing member 8 is an elastic member 1 made of rubber or the like.
1 to the fourth mount member 12, and this fourth
The mount member 12 is attached to an engine mount member 14 mounted on the vehicle body 13 with a mount bolt 15.

In the above configuration, even if the secondary excitation force of the engine rotation acts on the crank center as described above, the rigidity of the engine-transmission connecting member 6 is greatly increased, and the rigidity of the connection between the engine E and the transmission T is greatly increased. Therefore, secondary vertical bending vibration is not substantially induced in the power unit PU. Since the reinforcing member 8, which is firmly connected to the engine-transmission connecting member 6, is connected to the vehicle body 15 via the elastic member If, even if bending vibration secondary to engine rotation is caused in the power unit PU, However, in the process of transmitting this vibration to the vehicle body 13 side, the vibration energy is converted into thermal energy within the elastic member 11, so that the bending vibration of the power unit PU is not substantially transmitted to the vehicle body 3.

Therefore, even if the vertical bending vibrations of the primary and secondary engine rotations caused in the power unit PU are effectively suppressed, and even if some bending vibrations are caused, such bending vibrations are limited to the first to third vibrations. It is absorbed by the mount portion made up of the mount members 3 to 5 (see FIG. 3), the elastic member 11, and the fourth mount member 12, and is not substantially transmitted to the vehicle body. Therefore, in-vehicle noise (muffled sound) caused by bending vibration caused by the power unit PU can be effectively reduced.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view of an engine equipped with a power unit support device according to the present invention. FIG. 2 is a partially sectional front view of the engine shown in FIG. 1. FIG. 3 is an explanatory side view of a power unit showing an embodiment of the present invention. FIG. 4 is a diagram showing the characteristics of vertical bending vibration induced in the power unit by the secondary excitation force of engine rotation. FIG. 5 is a schematic perspective view of a conventional horizontally mounted power unit in which mounting members are provided at both ends of the torque roll shaft in the axial direction and on the sides near the center of gravity. PU...power unit, E...engine, T...
・Transmission, Q...Torque roll l1tl
, #l to #4... 1st to 4th cylinders, 1... cylinder block, 2... crankshaft, 3 to 5... first to third mount members, 6... engine. Transmission connection member, 8... Reinforcement member, 11... Elastic member,
12... Fourth mount member, 13... Vehicle body, 14...
・Engine mount member.

Claims (1)

[Claims] (1) In a power unit consisting of a transmission with a differential gear and an engine, mounting members are provided at both ends of the torque roll shaft in the axial direction, and the engine is mounted horizontally on a vehicle so that the axial direction is the axle direction. An engine-transmission connecting member is provided which is located below and has a substantially U-shaped cross section and whose tip is located forward of the center of gravity of the power unit when viewed in the axial direction of the crankshaft. - An automobile power unit support device characterized by being provided with a mount portion that elastically connects a transmission connecting member to a vehicle body side.