JPS5928946Y2 - Anti-vibration rubber for engine mounting parts in motorcycles - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vibration-proof rubber used for vibration-proofly mounting an engine to a body frame of a motorcycle.

This anti-vibration rubber generally fits into bolts that attach the engine to the vehicle body frame, and consists of a cylindrical part that absorbs vertical and longitudinal vibrations of the engine, and a flange part that absorbs horizontal vibrations.

If the outer circumferential surface of the cylindrical part is flattened and the engine side receiver is brought into contact with the hole around the entire circumference, there will be no relief when deforming, so the spring constant should be selected based only on the hardness of the rubber. No.

Therefore, the selection range of spring constant is narrow.

Therefore, it is known to provide grooves in the axial direction on the outer peripheral surface of the cylindrical portion in order to form relief portions during deformation, and the selection range of the spring constant becomes wider depending on the size and number of the grooves.

However, when a load due to engine vibration acts on the cylindrical part perpendicular to the axial direction, the spring constant is not constant because the thickness of the rubber is different depending on the direction in which the load is applied where the groove is located and where there is no groove. .

Also, because of the groove, the contact area with the engine per unit length of the cylindrical portion is small, resulting in rapid wear.

The object of the present invention is to provide a vibration isolating rubber for an engine attachment part of a motorcycle that solves the above-mentioned drawbacks.

Embodiments of the present invention will be described below with reference to the drawings.

The engine 1 is arranged in a space surrounded by a main pipe 21, a down tube 22, and a seat pillar tube 23 of a vehicle body frame 2.

And down tube 22 and seat pillar tube 23
A mounting bolt through hole 4 is opened in a bracket 3 which is provided by bolting, welding or the like.

A support portion 5 for the bracket 3 is provided protruding from the engine 1, and a mounting bolt through hole 6 is opened therein.

A cylindrical portion 8 of anti-vibration rubber is placed in the large diameter hole 7 outside the bolt hole 6.
1 are tightly fitted.

Between the outer surface of the engine 1 and the inner surface of the bracket 3,
A flange portion 82 of vibration isolating rubber is sandwiched.

The engine 1 is attached to the vehicle body frame 2 by inserting bolts 9 into the holes 4 of the bracket 3, the center holes of the vibration isolating rubbers 81 and 820, and the holes 6 of the support portion 5, and tightening nuts.

10 is a distance tube that fits into the bolt 9 and positions the left and right vibration isolating rubber.

The cylindrical portion 81 and the flange portion 82 of the vibration isolating rubber are formed separately.

The cylindrical part 81 is made by baking rubber around the inner pipe 11 and attaching the inch pipe 1 to the inner end surface thereof.
A flange 111 is provided which is integral with the flange 1 and a gap aeb is provided between the flange 111 and the engine case to allow normal vibrations of the engine.

This gap asb restricts abnormal vibrations of the engine and protects the vibration isolating rubber.

The flange portion 82 of the anti-vibration rubber is made of two annular plates 12.
The rubber is baked between 1 and 122 and is fixed, so both plays)
121 and 122 are in contact with the bracket 3 and the engine 1, respectively.

The flange portion 82 is connected to the outer annular plate 12.
1 is fitted and supported by the boss 811 of the cylindrical portion 81, and a gap C is formed between the inner circumference of the flange portion 82 and the boss 811.

A thin rubber layer is formed on the outer peripheral surface of the boss 811, and the outer annular plate 121 is fitted against the elasticity of the thin rubber layer.

The cylindrical portion 81 and the flange portion 82 are each given elastic characteristics that match the vibrations of the engine 1.

When the flange portion 82 receives a compressive load, the deformation can escape to the gap C and the outer periphery, and the deformation is free.

The cylindrical portion 81 and the flange portion may be formed integrally.

The present invention is characterized in that a large number of stages 12 are spirally provided on the outer peripheral surface of the cylindrical portion 81 of the vibration-proof rubber as shown in FIG.

Therefore, even if a load is applied to the cylindrical portion 81 from any direction around the entire circumference, the cylindrical portion 81 deforms freely and the spring constant remains constant.

By selecting the helical angle of the groove 812, the size and number of grooves, etc., there is an advantage that the spring constant can be set in accordance with the vibration of the engine.

Furthermore, since the groove 812 is spiral, a large contact area with the engine can be ensured per unit length of the cylindrical portion 810, resulting in less wear.

[Brief explanation of drawings]

Figure 1 is a side view showing how the engine is attached to the vehicle body frame, Figure 2 is a longitudinal side view of the vibration-isolating rubber in use, Figure 3 is a front view of the cylindrical part of the vibration-isolating rubber, and Figure 4 is a side view showing how the engine is mounted to the vehicle body frame. Its side view. 1 is an engine, 2 is a vehicle body frame, 81 is a cylindrical portion of anti-vibration rubber, 82 is a flange portion of anti-vibration rubber, 812 is a spiral groove, and 9 is a mounting bolt.

Claims (1)

[Scope of utility model registration request] A cylindrical anti-vibration rubber that fits over the mounting bolts of the engine and the vehicle body frame to absorb engine vibrations.This anti-vibration rubber for the engine attachment part of a motorcycle has multiple grooves spirally formed on its outer circumferential surface.