JPS6323006B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite engine mount suitable for use in automobiles.

Automotive engine mounts absorb large low-frequency displacement inputs to prevent the engine from shaking due to uneven road surfaces, etc., and also prevent engine vibrations from propagating to the passenger compartment, reducing interior noise. In order to suppress the increase in the amount of displacement, it is necessary to have characteristics that can also absorb high-frequency displacement input with a small amount of displacement.

Composite engine mounts were developed to meet this need. They incorporate a hydraulic damping mechanism into an elastic member such as rubber that is interposed between the engine and the frame and which acts on changes in the height of this elastic member. be.

However, in conventional composite engine mounts in which the hydraulic damping mechanism starts acting at the same time as the height change of the elastic member starts, the change in the spring constant is proportional to the change in the damping force, and the low frequency displacement input is sufficiently suppressed. If the damping force is set large enough to absorb the high-frequency displacement input, the spring constant will be too large to absorb the high-frequency displacement input, and the high-frequency displacement input will not be able to be sufficiently absorbed. If it was set to a small value, the damping force would be small and there would be a drawback that low frequency displacement input could not be sufficiently absorbed.

SUMMARY OF THE INVENTION The object of the present invention is to obtain a composite engine mount that does not have the above-mentioned drawbacks and is simple in construction.

Hereinafter, the present invention will be clarified by describing embodiments of the present invention based on the drawings. In one embodiment of FIGS. 1 and 2, a composite engine mount 1 has a hollow cylindrical body 2 made of an elastic material such as rubber.
Frame plates 3 and 4 are galvanically bonded to both ends of this hollow cylindrical body 2, an engine side mounting member 5 is fixed to the frame plate 3 with bolts 6, and a frame plate 4 is fixed to the frame plate 4 by bolts 6. A mounting member 7 is fixed with a bolt 8. The engine-side mounting member 5 has a mounting bolt 9 fixed at the center of the center part pushed upward from the peripheral edge in contact with the frame plate 3, and the frame-side mounting member 7 also integrally has a mounting bolt 10 at its center. There is.

The stepped portion between the center and the peripheral edge of the frame plate 3 and the engine-side mounting member 5 is fixed by liquid-tightly clamping the peripheral edge of the first diaphragm 11 and the partition plate 12 below the first diaphragm 11.
The frame plate 4 and the frame-side mounting member 7 clamp and fix the peripheral edge of the second diaphragm 13 in a fluid-tight manner.
This first diaphragm 11, the partition plate 12 and the second
A space surrounded by the diaphragm 13 by the hollow cylinder 2, the engine-side mounting member 5, and the frame-side mounting member 7 is connected to the first working fluid chamber 14 inside the hollow cylinder 2 and the partition plate 12. A second hydraulic fluid chamber 16 communicates with the first hydraulic fluid chamber 14 through an orifice 15 provided therein, a first gas chamber 17 above the first diaphragm 11, and a second gas chamber below the second diaphragm 13. It is divided into a chamber 18. The first gas chamber 17 is a hole 19 provided in the engine side mounting member 5.
The second gas chamber 18 communicates with the atmosphere through a hole 20 provided in the frame-side mounting member 7. Both the first diaphragm 11 and the second diaphragm 13 are made of an elastic body such as rubber, but the rigidity of the second diaphragm 13 is the same as that of the second diaphragm 13.
The thickness of the diaphragm 13 is the same as that of the first diaphragm 11.
or the hardness of the elastic material of the second diaphragm 13 is made larger than that of the first diaphragm 1.
By making the hardness of the elastic material larger than that of the first diaphragm 11, the rigidity of the second diaphragm 11 is set to be greater than that of the first diaphragm 11, and when the composite mount 1 is statically loaded with the weight of the engine, the second diaphragm 13 as shown in FIG. is separated from the dish-shaped inner surface of the frame-side mounting member 7.

When low frequency displacement input is input, the first hydraulic fluid chamber 14
In order to suppress the expansion of the diameter of the hollow cylindrical body 2 due to the hydraulic pressure and increase the damping force, a metal ring 21 is galvanically bonded to the outer periphery of the hollow cylindrical body 2. A slope is provided so that the diameter is smaller than at both ends.

In the composite engine mount 1 configured as described above, when a displacement is input to reduce the height, the second diaphragm 13 is elastically deformed downward in response to the increase in the hydraulic pressure in the first working fluid chamber 14, and the second diaphragm 13 is elastically deformed downward. The volume of the first hydraulic fluid chamber 14 does not decrease. After the downward elastic deformation of the second diaphragm 13 progresses until it comes into close contact with the dish-shaped inner surface of the frame-side mounting member 7, the volume of the first hydraulic fluid chamber 14 decreases
, the hydraulic pressure in the first hydraulic fluid chamber 14 suddenly increases, and
The high-pressure liquid flows through the orifice 15 to the second hydraulic fluid chamber 16, and a damping effect is performed.

As is clear from the above explanation, when the height change of the composite engine mount 1 is small, the damping effect using the orifice 15 is not performed.
The spring constant is small, which sufficiently absorbs high frequency displacement inputs. In addition, if the height change of the composite engine mount 1 is large, the orifice 1
5, low frequency displacement inputs are also sufficiently absorbed.

In the other embodiment shown in FIG. 3, in order to reduce the number of parts and omit internal processing of the frame-side mounting member 107,
The second diaphragm 113 is integrally formed with the hollow cylindrical body 102 and curved upward. In the embodiment shown in FIG. 4, a projection 213a is formed on the lower surface of the second diaphragm 213. Due to the elastic deformation of the second diaphragm 213, the projection 213a closes the hole 220 during the elastic deformation stroke of the second diaphragm 213. Since the second gas chamber 218 is sealed, the rigidity of the second diaphragm 213 is increased, and as a result, nonlinear characteristics can be obtained. In FIGS. 3 and 4, constituent members corresponding to those in the embodiment shown in FIGS. 1 and 2 are indicated by the reference numerals used in the description of the embodiment shown in FIGS. 1 and 2 plus 100 or 200.

In each of the embodiments shown in FIGS. 1 to 4, both gas chambers are communicated with the atmosphere, but it is also possible to fill these chambers with pressurized gas.

In summary, the present invention is characterized in that it is provided with a second diaphragm that adjusts the relative relationship between the height change of the hollow cylinder and the volume change of the first working fluid chamber inside the hollow cylinder. This makes it possible to sufficiently absorb both low-frequency displacement input and high-frequency displacement input. Moreover, the structure is simple.

[Brief explanation of the drawing]

1 is a longitudinal sectional view of one embodiment of the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a longitudinal sectional view of another embodiment, and FIG. 4 is a longitudinal sectional view of another embodiment. 1,101,201...Composite engine mount, 2,102,202...Hollow cylinder body, 5,10
5,205...Engine side mounting member, 7,10
7,207...Frame side mounting member, 11,11
1,211...first diaphragm, 12,11
2,212... Partition plate, 13,113,213...
...Second diaphragm, 14,114,214...
First hydraulic fluid chamber, 15,115,215...orifice, 16,116,216...second hydraulic fluid chamber,
17,117,217...first gas chamber, 18,1
18,218...Second gas chamber.

Claims (1)

[Claims] 1. A hollow cylindrical body made of an elastic material, an engine-side mounting member and a frame-side mounting member that are fixed to one end and the other end of the hollow cylindrical body, respectively, and form a space surrounded within the hollow cylindrical body, and a frame-side mounting member disposed within the space. a first diaphragm that is arranged in the space and forms a first gas chamber between the engine mounting member and the first diaphragm that is disposed within the space and forms a second gas chamber between the frame mounting member and the first diaphragm. a first hydraulic fluid chamber is formed between a rigid second diaphragm and the second diaphragm disposed within the space;
a partition plate provided with an orifice that forms a second hydraulic fluid chamber between the diaphragm and communicates the first hydraulic fluid chamber with the second hydraulic fluid chamber; An engine mount in which the second diaphragm contacts the frame-side mounting member, and then, due to the displacement of the hollow cylinder, the medium in the first working fluid chamber flows from the orifice into the second working fluid chamber to perform a damping action. .