JPS6234816A - Engine mount structure - Google Patents

Abstract

PURPOSE:To minimize the propagation of vibration to a body by configurating a device in such a way that, when a transversally mounted engine is supported by a body at four points: two upper and two lower points by way of rubber, and two of the said upper supports are made to be free from rotational vibration from an engine torque around a rolling axis. CONSTITUTION:When a power plant 4 which consists of an engine 7, a transmission 8, and of a differential gear 19, is transversally supported by a body so as to allow a torque axis X of the engine 7 to be directed to the lateral direction of the body 1, a mount member 3 which is installed on the body 1, is adapted to hold the power plant in such a way that the lower front and lower rear sections of the power plant 4 are supported by both NO.1 and NO.2 elastic supports 11 and 12. In addition, the upper front and upper rear sections of one side of the power plant 4 are supported by both NO.3 and NO.4 elastic supports 13 and 14 over a side frame 1a of the body 1. And both NO.3 and NO.4 elastic supports 13 and 14 are configurated to be free from rotational vibration from an engine torque around a rolling axis.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an engine mount structure.

(Prior art) For example, in a front-engine, front-drive vehicle, the power plant consisting of the engine, transmission, etc. is installed in the engine room at the front of the vehicle so that the engine's torque shaft (crankshaft) faces in the left-right direction of the vehicle. It is customary to be installed horizontally, but in that case, the main axis of inertia of the engine's rolling motion and the axis of rotation of the tires are parallel to each other, so that the torque reaction force due to the rotation of the tires is directly directed in the rolling direction of the engine. act. For this reason, in an axle equipped with a transversely mounted power plant as described above, the engine is supported by the vehicle body so that its own vibrations are less likely to be transmitted to the vehicle body, and the engine is also supported by the vehicle body in a manner that prevents the engine from transmitting its own vibrations to the vehicle body. is required to be supported so that it can be stopped.

If the engine is supported without this requirement being met, rotational vibrations around the main axis of inertia will be transmitted to the car body when the engine is running at low speeds, while rotational vibrations around the torque roll axis will be transmitted to the car body when the engine is running at high speeds, causing noise. There is a problem that the amount of noise increases and the ride comfort deteriorates.

Here, the above-mentioned torque roll axis is, as is well known, an axis determined by the torque axis where torque is generated and the principal axis of inertia, and is the rotation of the power unit when torque around the crankshaft is applied to the unrestrained power unit. The power unit rotates around the torque roll axis above the road when the engine rotates at high speeds, that is, when the forced vibration frequency of the power unit is sufficiently larger than the natural frequency and receives high-frequency torque fluctuations. It is something to do.

The main axis of inertia passes through the center of gravity of the power unit with respect to a horizontal axis parallel to the output shaft of the differential gear, and is inclined at an angle α of about 10° to 15° from the horizontal, and the torque roll axis passes through the center of gravity and is inclined at an angle α of about 10° to 15° from the horizontal. It is inclined with respect to the principal axis of inertia by an angle β having the relationship between α and the following equation.

Lan β-(Ix / Iz) ・tan
a However, Ix is a moment about the principal axis of roll inertia, and Iz is a moment about the principal axis of yawing inertia, which is approximately vertical and passes through the center of gravity.In general, IX<IZ, so α>β.

However, even when the engine is supported in accordance with the above requirements, in the conventional engine mount structure, as described in Utility Model Application Publication No. 1983-833, the side of the horizontally placed engine is The part is supported by the side frame of the vehicle body, that is, the frame extending in the longitudinal direction of the vehicle body, although it is via a bracket. There is a problem in that the noise is transmitted to the various panels fixed to the vehicle, causing muffled noise inside the vehicle.

(Objective of the Invention) An object of the present invention is to provide an engine mount structure that can reduce noise that is caused by engine vibrations and is trapped in a vehicle interior.

(Structure of the Invention 1ii) The present invention is an engine mount structure that supports two upper parts and two lower parts of a horizontal power plant, in which an engine and a transmission are integrally combined, on a vehicle body via rubber, A body frame provided on the side of the vehicle body and extending in the longitudinal direction of the vehicle body is configured such that two upper portions of the power plant are not restrained from rotational vibrations centered on the torque roll axis of the engine, The device is characterized in that two mount members are attached, each of which supports the device swingably.

(Operations and Effects of the Invention) As described above, in the engine mount structure of the present invention, the two upper parts of the power plant are protected against rotational vibrations about the torque roll axis of the engine by the two mount members. Since the two mount members are supported in a swingable manner without being restrained, transmission of harmful vibrations to the body through the vehicle body frame to which the two mount members are attached can be reduced.

(Embodiment) Hereinafter, an engine mount structure according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

2r! 1, 2, and 3 show the arrangement of the power plant. In FIG. 1, the front of the vehicle is indicated by an arrow F, and the rear of the vehicle is indicated by an arrow R.

Inside the engine compartment 2 formed in the front part of the vehicle body 1, a side frame 1a is located on the side thereof, and a power plant mount member 3 is located inside the side frame 1a.
, each extending in the longitudinal direction of the vehicle body. The mount member 3 is attached to the vehicle body 1 with bolts 6 through anti-vibration rubbers 5 at both front and rear ends 3a and 3b, respectively.
It is installed using 6.

The power plant 4 includes an engine 7 and an engine 7.
It is composed of a transmission 8 attached to one side and a differential gear device 9 integrated with the transmission 8, and is mounted horizontally so that the torque axis In addition, drive shafts (not shown) extend from the differential gear device 9 in the left and right directions of the vehicle body, and left and right wheels (not shown) are connected to their ends. Note that in the figure, the symbol G indicates the center of gravity of the power plant 4.

As particularly clearly shown in FIG. 2, the power plant 4 has its lower front and rear parts supported by 'fJ1 and the second elastic support members 11 and 12, and its upper front and rear parts supported by 3 and fourth elastic support members 13 and 14
are supported on the member 3 and the side frame 1a, respectively. That is, among the elastic support members 11 to 14, the first and second elastic support members 11.
Reference numeral 12 is arranged at a lower part of the front end of the transmission 8 and a lower part of the rear end of the differential gear device 9, that is, sandwiching the torque axis X and the torque roll axis Y in the longitudinal direction of the vehicle body, and is arranged at a predetermined distance from the member. The power plant 4 is elastically supported on the third
and the fourth elastic support means 13 and 14 are the engine 7
The power plant 4 is elastically supported on the side frame 1a at the front and back of the upper part of one side.

The first elastic support member 11 (the same applies to the second elastic support member 12) is a rubber bush consisting of an inner cylinder 15, an outer cylinder 16, and an elastic rubber 17 disposed between them, as shown in FIG. Consists of power plant 4
The inner cylinder 15 is pivotally supported by a bracket 18 (bracket 19 for the second elastic support member 12) fixed to the
And the outer cylinder 16 is attached to the mounting member 3 at the attachment part 16a.
This reduces transmission of the vibrations of the power unit 4 to the member 3, that is, to the vehicle body 1.

The fourth elastic support member 14 (the same applies to the third elastic support member 13) has a substantially rectangular bracket 20 attached to the side frame 1a, as shown in Figure 1g5. A ball bearing 22 is supported on this bracket 20 via an elastic rubber 21. A large-diameter shaft 23 is supported by this pole bearing 22, and from the side of the large-diameter shaft 23 on the power plant 4 side, a small-diameter shaft 24 integrated with this shaft 23 is attached to the rear surface of the power plant 4. It extends along the section. The central axis B of this small diameter shaft 24 is the sixth
As clearly shown in the figure, the large diameter shaft 23
It is eccentric from the central axis A. Further, the center axis C of the small diameter shaft 25 of the third elastic support member 13 is also eccentric from the center axis of the large diameter shaft 26, as shown in FIG. Further, the four central axes are arranged so that when the power plant 4 is not vibrating, the axes A, B, and Y are on a straight line, and the axis C , Y are arranged in a straight line. The inner ends of the shafts 24 and 25 are supported by bearings 27. Therefore, the four shafts 23, 24, 25, 26 have quadrilateral rings Δ, B,
, CSD, and the upper part of the power plant 4 is supported at the midpoint E of the arm BC.

When axis C moves angularly by 10 degrees around the axis, axis BSY and point E move as shown in FIG. When the axis C moves within a range of ±10 degrees, the point E moves approximately on the circumference around the axis Y, as shown by the hatching. Therefore, the roll vibration of the engine is made into a vibration around the torque roll axis, that is, the rotational vibration around the torque roll axis of the engine is not restrained. Therefore, rotational vibration around the torque roll axis of the engine is less likely to be transmitted to the side frame la.

Furthermore, when the point C moves by more than ±10 degrees, the axis Y will in each case undergo a significant upward movement, which means that the power plant 4 will be lifted, so that due to the weight of this power plant 4, Movements of axis C of ±10 degrees or more are damped. Therefore, the link mechanism functions to reduce the transmission of rotational vibrations about the torque roll axis Y of the engine to the side frame 1a, and also acts as a stopper against large vibrations such as when starting the engine.

In the above embodiment, the upper part of the power plant is supported at the front and rear positions by two elastic support members, but as shown in FIG. Alternatively, even if it is arranged only on one side of the rear part, almost the same function as above can be obtained.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an engine mount structure according to an embodiment of the present invention, FIG. 2 is a left side view of the mount structure, FIG. 3 is a rear view of the mount structure, and FIG. Line IV- in Figure 1
5 is an enlarged view showing the main parts of the mount structure, FIG. 6 is a sectional view taken along line Vl-Vl in FIG. 5, and FIG. 7 is a mount structure of the present invention. FIG. 8 is a diagram similar to FIG. 2 of an engine mount structure according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Vehicle body, 1a... Side frame, 4... Power unit, 11... First elastic support member, 12... Second elastic support member,
13...Third elastic support member, 14...
Fourth support member, 23.26... large diameter shaft,
24.25...Small diameter shaft. Figure 1n Figure 2'$3 Figure

Claims (1)

[Claims] An engine mount structure that supports two upper and two lower parts of a transverse power plant, in which an engine and a transmission are integrally combined, on a vehicle body via rubber. The vehicle body frame extending in the front-rear direction includes two mounts that swingably support the two upper parts of the power plant so as not to restrain them from rotational vibrations about the torque roll axis of the engine. An engine mount structure characterized in that a member is attached.