JPS5942528Y2 - engine mounting device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an engine mounting device for mounting an engine on a vehicle body of a vehicle such as an automobile.

In general, engine vibration sources include crankshaft torque fluctuations, unbalanced forces of rotating masses, inertial forces of reciprocating masses, unbalanced moments of inertia, and vibrations due to variations in combustion. This induces bending vibrations, torsional vibrations, and vibrations in various parts of the vehicle.

Countermeasures against these problems include considering the moment of inertia of the flywheel, reducing the inertia of the reciprocating mass, or using a dynamic damper to measure the attenuation of the amplitude during resonance. It is also an effective method to use measures to insulate vibrations from being transmitted to the vehicle body.

This engine vibration is mainly transmitted to the vehicle body through an engine mounting device that supports the engine.

Conventionally, engine mounting devices have generally been constructed to incorporate resilient elements such as rubber or springs.

This allows a certain degree of relative displacement between the engine and the car body by elastically supporting the engine against the car body.
This is intended to prevent engine vibrations from being transmitted to the vehicle body through the elastic deformation.

For example, as shown in FIG. 1, an engine mounting 1 consists of an upper plate 2 and a lower plate 3 that are parallel to each other, and a mounting rubber 4 that is inserted between these plates. are connected to the cylinder block and vehicle body, respectively.

In addition, as shown in FIG. 2, a substantially cylindrical mounting rubber 4 is inserted between the upper plate 2 and the lower plate 3 to form an air chamber 5 inside, and nozzle holes 6 are formed in either of the plates. There is a device that connects the inside of the air chamber 5 with the atmosphere.

However, the engine mounting 1 shown in FIG. 1 relies only on the mounting rubber 4.

For this reason, this type of mounting rubber 4 must necessarily have a large spring constant in order to support the mass of the engine and transmission, and as a result, sufficient vibration isolation cannot be expected.

In addition, in the case shown in Fig. 2, when a load is applied in the axial direction, the spring characteristics of the mounting rubber 4 and the deformation of the hollow mounting rubber 4 cause the internal air to flow in and out through the nozzle hole 6, resulting in extremely Effective buffering and damping can be provided.

However, in this case, since the air chamber 5 is open to the atmosphere through the nozzle hole 6, the flow noise generated by the flow resistance when passing through the nozzle hole 6 during compression and tension is large and contributes to noise. .

The purpose of the present invention is to eliminate these drawbacks and provide an engine mounting device having high damping characteristics using the spring characteristics of the mounting rubber and the damping force of the air spring. By interposing an elastic body between the inner cylinder and the outer cylinder to form two air chambers separated from the atmosphere, and by providing a communication path for air to flow between the rain air chambers, the mounting rubber The damping button and the vibration damping performance are improved by utilizing the spring characteristics of the air, the spring characteristics of the air, and the air attenuation when air flows between the rain and air chambers.

Next, one embodiment of the present invention will be described in detail with reference to FIGS. 3 and 4.

Reference numeral 11 indicates a metallic outer cylinder, and 12 indicates a metallic inner cylinder, which are arranged concentrically with a certain gap between them.
An elastic body 13 is fitted between the outer and outer cylinders, and two air chambers 14 and 15 are separated from the atmosphere by the inner wall of the outer cylinder, the outer wall of the inner cylinder, and the elastic body 13 in the radial and axial directions of the outer cylinder 11. It is formed to be approximately symmetrical.

A sling N7 is provided in the circumferential direction of the outer circumferential surface of the mounting bolt 16 that is passed through the inner cylinder 12, and a small hole 18 is bored in the radial direction in the inner cylinder 12. The rain air chambers 14 and 15 are communicated with each other.

Further, the inner cylinder 12 is attached to the vehicle body via a mounting bracket 19, while the outer cylinder 11 is attached to the engine cylinder block side via a mounting bracket (not shown).

Of course, this installation can also be done in reverse.

According to this configuration, the outer cylinder 11 and the inner cylinder 12 are relatively displaced via the elastic body 13 due to vibrations of the engine or the vehicle body.

At this time, when the volume of one of the air chambers 14 or 15 decreases, air is allowed to flow from one air chamber to the other.

This decrease is accompanied by a corresponding increase in the volume of the other air chamber, whereby the air is subjected to pressure from the contracted one air chamber to the expanded other air chamber through the small holes 18 and slits 17. be put into.

As described above, according to the present invention, the spring characteristics of the elastic body 13, the spring characteristics of the air, and the passage area of the fluid when the air sealed inside the air chambers 14 and 15 flow through the slits 17 and the small holes 18. Engine/vibration can be controlled more effectively due to the fluid resistance generated by controlling the engine/vibration.

Also, compared to the conventional model shown in Figure 2, the air chamber is 2 times larger.
The slits and small holes are surrounded by the outer cylinder wall and the elastic body, so the air can flow from one air chamber to the other. This has the effect of creating noise due to the flow of air as it flows in and out of the air.

In this embodiment, damping by air is used, but it is of course possible to use other highly damping fluids.

Further, in the present invention, the communication passage is formed in the inner cylinder and the mounting bolt, but it is also possible to provide a communication passage connecting the two air chambers in the elastic body itself.

However, in this case, when a large load is applied, the communication passage itself may deform and close the communication passage.

Furthermore, after long-term use, cracks are likely to occur in the communication passage portion of the elastic body, which poses a problem in durability.

According to the present invention, by always maintaining a constant flow path area, an air damping force corresponding to the design conditions can be obtained, and an engine mounting device with high durability can be obtained, which is considered to be more preferable. .

[Brief explanation of the drawing]

1 and 2 are sectional views showing a conventional engine mounting device, FIG. 3 is a sectional view showing an embodiment of the present invention, and FIG. 4 is a sectional view taken along line [V-IV] in FIG. 11... Outer cylinder, 12... Inner cylinder, 13... Elastic body,
14゜15...Air chamber, 16...Mounting bolt, 17
...slit, 18...small hole.

Claims (1)

[Scope of utility model registration request] A tubular inner cylinder, an outer cylinder disposed concentrically with the inner cylinder, and a gap between the inner and outer cylinders are fitted, and the gap is covered in the radial direction by the inner wall of the outer cylinder and the outer wall of the inner cylinder. 2 so that it is approximately symmetrical to
An engine mounting device comprising: an elastic body forming two spaces; and a communication passage connecting the two spaces by a support shaft inserted into the inner cylinder and a small hole passing through the inner cylinder.