JPS6228547A - Vibration control device of engine for car - Google Patents

Abstract

PURPOSE:To damp vibration effectively by supporting an engine on a rotary end of a coupling link, supporting same on a car body frame, and interposing an elastic member between the coupling link and the car body or the engine. CONSTITUTION:An engine is supported in such a manner as to vibrate vertically to a car body frame, and a coupling link 33 is rotatably supported on a bracket 30 of the car body frame. An elastic member 37 is interposed between a support bolt 32 of the bracket 30 and the coupling link 33. In this arrangement, when the engine is vibrated to turn the car body frame and the coupling lkin relatively, the elastic member can be elastically torsional deformed to effectively damp vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vibration isolating device for an engine for a vehicle such as a motorcycle.

(Prior Art) Some motorcycles have an engine supported by a vehicle body frame via a vibration isolating rubber, which is an elastic member, so that engine vibrations are not transmitted to the vehicle body frame.

In the above configuration, in order to more effectively prevent vibrations from being transmitted from the engine to the vehicle frame, a balance weight that rotates at the same speed as the engine crankshaft is provided, and the inertia of this balance weight reduces engine vibrations. It has been proposed that vibrations of the engine are generated in approximately one direction, and the elastic coefficient of the vibration isolating rubber in this direction is made small to effectively absorb engine vibrations.

(Problems to be Solved by the Invention) In the above configuration, the vibration isolating rubber is compressively deformed in the direction in which the engine vibrates.
If such compression-type vibration isolating rubber is made to have a sufficiently small elastic modulus, the vibration isolating rubber will normally become large, which is undesirable, and therefore, there are large restrictions on reducing the elastic modulus. Furthermore, in the above configuration, the vibration isolating rubber is directly subjected to engine vibrations, so the degree of freedom in design for vibration absorption is limited.

(Object of the Invention) This invention was made in view of the above-mentioned circumstances, and it is an object of the present invention to cause engine vibration to occur in approximately one direction, and to increase the size of an elastic member for absorbing this vibration. The purpose of the present invention is to effectively attenuate vibrations by reducing the elastic coefficient thereof, and to expand the degree of freedom in design for vibration absorption.

(Structure of the Invention) In order to achieve the above object, the present invention is characterized in that a plurality of connecting links rotatable in the same direction as the vibration direction of the engine are pivotally supported on the vehicle body frame. The engine is supported by the vehicle body frame by pivotally supporting the engine at the rotating end of the link, and an elastic member is provided so as to be elastically torsionally deformed between at least one of the vehicle body frame and the engine and the connecting link. The point lies in the intervention.

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

1 to 4 show a first embodiment.

In the figure, 1 is a motorcycle which is an example of a vehicle, and 2 is a body frame. The body frame 2 is a cradle-type frame, and has a steering shaft tube 3 at its # part. A front fork 4 is supported on the steering shaft tube 3, a front wheel 5 is supported on the lower end of the front fork 4, and a handle 6 is attached to the upper end.

On the other hand, a rear arm 9 is pivotally supported at the rear of the vehicle body frame 2 via a pivot shaft 8 so as to be vertically swingable, and a rear wheel 10 is supported at the swinging end of this rear arm 9. 11 is a buffer.

An engine 13 is provided within the frame of the vehicle body frame 2. A transmission device linked to this engine 13 is provided,
The output chain wheel 14 of this transmission and the input chain wheel 15 which rotates together with the rear wheel 10 are interlocked and connected by a wrap chain 16.

A carburetor 18 is connected to the intake boat of the engine 13, and a fuel tank 19 for supplying fuel to the carburetor 18 is supported by the vehicle body frame 2. Also, the same engine 13
An exhaust V20 is connected to the exhaust boat. 21 is a sheet.

The engine 13 has a crankcase 22, and a crankshaft 23 whose axis extends in the vehicle width direction is supported on the crankcase 22. A cylinder 24 is projectingly provided on the crankcase 22, and a piston 25 is fitted into the cylinder 24 so as to be slidable in the vertical direction. This piston 25
and the crankshaft 23 are connected by a connecting rod 26, and as the piston 25 reciprocates in the vertical direction, the crankshaft 23 is driven to rotate, thereby rotating the rear wheel 10 via a winding chain 16 or the like. .

When the engine 13 is driven, the vibration is generated in approximately one direction. To explain this, the crankshaft 23 has a large end 26b of the connecting rod 26.
A rough weight 28 is attached at a position displaced by 180'C, and this balance weight 28 rotates together with the crankshaft 23. The inertial force of the balance weight 28 causes the engine 13 to vibrate in approximately one direction.

Here, the small end 2 of the connection s26 including the piston 25
The reciprocating mass on the 6a side is Wa, and the large end 2 of the above-mentioned VC rod 26 is
The rotating mass on the 6b side is wb, and the balance weight 28
Let Wc be the rotating mass of the engine 1, for example, Wa+Wb=Wc, then the vertical inertial force is balanced and the engine 1
The vibration No. 3 occurs only in approximately one direction, the front-rear direction. Further, for example, if W b = W c, the rotational mass is balanced, so that the vibration of the engine 13 will occur only in approximately one direction, the vertical direction, due to Wa.

In the above configuration, the engine 13 is connected to the vehicle body frame 2.
The configuration for supporting this will be explained.

In this embodiment, the engine 13 is operated in the vertical direction (7).
E' is supposed to vibrate in one direction, and the engine
is supported with respect to the vehicle body frame 2 so as to be allowed to vibrate relative to the above-mentioned vertical direction.

That is, a pair of brackets 30, 30 are screwed to the front and rear of the vehicle body frame 2, respectively, by bolts 31, and connecting links 33 are movable up and down by support ports 32 installed on the brackets 30, 30. is supported by. The crankcase 22 of the engine 13 is attached to a pivot port 34 at the rotating end of each connecting link 33.
The engine 13 is pivotally supported via a bushing 35 that is externally fitted on the bushing 35, thereby allowing the engine 13 to vibrate in the vertical direction.

The support port 32 has a square cross-sectional shape, and there is a gap between the support port 32 and the connecting link 33.
．． A pair of left and right elastic members 37, 37 are interposed, which are elastically torsionally deformed by the relative rotation of the members 33.

Each of the elastic members 37 includes an inner cylinder 38 that is externally fitted onto the support port 32 so as not to rotate relative to the support port 32, an outer cylinder 39 that is press-fitted into the connection hole 33a of the connection link 33, and an inner cylinder 38, an outer cylinder 38, and an outer cylinder 38. 39 and a cylindrical anti-vibration rubber 40 which is vulcanized and bonded to the container cylinders 38 and 39. A spacer 41 is fitted onto the support port 32 and interposed between the left and right inner cylinders 38 and 38. In the above case, the support port 32 is a port with a circular cross section, and the support port 32 is
The inner cylinder 38 may be fitted onto the outside using serrations.

When the engine 13 is driven and vibrates up and down, each connecting link 33 tolerates this vibration and rotates up and down. Then, the vibration of the engine 13 is absorbed by the elastic torsional deformation of the vibration isolating rubber 40 due to the relative rotation between the support port 32 on the body frame 2 side and the connection link 33, and the vibration is transmitted to the body frame z side. Prevented. Also, in this case,
The engine 13 is vibrated in a direction perpendicular to the line connecting the center points of the output chain wheel 14 and the input chain wheel 15 (the line connecting the center points of the output chain wheel 14 and the input chain wheel 15). This prevents the encircling chain 16 from loosening or becoming excessively tensioned due to the vibrations of the engine 13.

Note that the elastic member 37 may be interposed between the engine 13 and the connecting link 33 with the same configuration as above. Further, although the rear wheel 1o is of a chain drive type, it may be of a shaft drive type.

On the other hand, the upper end of the engine 13, ie, the upper end of the cylinder 24, is connected to the upper part of the vehicle body frame 2 by a shock absorber 43. Although this shock absorber 43 damps vertical vibrations of the engine 13, this shock absorber 43 is not essential to the present invention.

The shock absorber 43 is provided with a cylindrical case 44 whose axis is vertically oriented, and a piston 45 is fitted into the case 44 so as to be slidable up and down. Also, same case 4
4 is filled with oil 46, and a throttle hole 47 is formed in the piston 45 to communicate two oil chambers in the case 44 partitioned by the piston 45.

The case 44 is connected to a bracket 48 on the vehicle body frame 2 side, and a rod 49 connected to a piston 45 is connected to a bracket 50 on the cylinder 24.

When the engine 13 vibrates up and down, the piston 45 moves up and down within the case 44 accordingly. At this time, the oil 46 moves from one oil chamber to the other oil chamber through the throttle hole 47, but due to the large flow resistance of the oil 46 when passing through the throttle hole 47, a large damping force is generated and the engine 13 vibrations are damped.

Figure w45 shows the second embodiment. This will be explained with respect to a configuration different from the above embodiment.

The engine 13 shown in the figure is also configured to vibrate in approximately one direction, up and down. A longitudinally oriented front shock absorber 5 is provided between the longitudinally intermediate part of the connecting link 33 that supports the front part of the engine 13 toward the vehicle body frame 2 and the vehicle body frame 2.
1 will be constructed. On the other hand, the rear end of the connecting link 33 that supports the rear part of the engine 13 on the vehicle body frame 2 side extends rearward, and a rear shock absorber 52 whose axis is vertically oriented is installed between this extended end and the vehicle body frame 2. ing.

The front and rear shock absorbers 51 and 52 have the same structure as the shock absorber 43. For example, when the engine 13 vibrates and moves upward, the piston of the front shock absorber 51 slides upward within the case 44 to damp this vibration. On the other hand, when the engine 13 moves upward in the same manner as described above, the piston of the rear shock absorber 52 moves in conjunction with the rear end of the connecting link 33 that rotates downward about the support port 32, and moves the case 44.
It slides downward inside to dampen this vibration. Note that the front and rear shock absorbers 51 and 52 are not essential components of the present invention.

(Effects of the Invention) According to the present invention, a plurality of connecting links that are rotatable in the same direction as the vibration direction of the engine that vibrates in one direction are pivotally supported on the vehicle body frame, and the rotating end of each connecting link is The engine is supported by the body frame,
Since an elastic member is interposed between at least one of the body frame and the engine and the connection link, when the engine vibrates and at least one of the body frame and the engine and the connection link rotate relative to each other, This rotation allows the elastic member to be elastically torsionally deformed. In this case, the elastic member that undergoes torsional deformation is smaller than conventional compression type elastic members, and the elastic modulus can be made sufficiently small, so the elastic member can be made larger by setting the natural frequency lower. Engine vibrations can be effectively damped without causing any damage.

In addition, since the elastic member is interposed between the vehicle body frame, the engine, and the connecting link for supporting the engine on the vehicle body frame, the engine can be adjusted by changing the angle and length of the connecting link. The conditions for support can be changed arbitrarily. Therefore, the degree of freedom in designing for vibration absorption of the engine is expanded.

[Brief explanation of drawings]

The figures show embodiments of the invention, and Figures 1 to 4 are
In the examples, Fig. 1 is an overall side view of a motorcycle partially shown as a cylindrical diagram, Fig. 2 is a sectional view taken along the line II'-II in Fig. 1, and Fig. 3 is a cross-sectional view taken along the line II'-II in Fig. 2. III-III line arrow sectional view,
FIG. 4 is a sectional view of the shock absorber, and FIG. 5 is a partial view of the second embodiment corresponding to FIG. 1. 1. Motorcycle (vehicle), 2. Body frame, 13
...Engine, 23..Crankshaft, 28..Balance weight, 33..Connection link, 37..Elastic member.

Claims (1)

[Claims] 1. In a vehicle that is equipped with a balance weight that rotates at the same speed as the engine crankshaft, and the inertia of this balance weight causes the engine to vibrate in almost one direction, the engine is rotated in the same direction as the engine vibration direction. A plurality of freely movable connecting links are pivotally supported on the vehicle body frame, an engine is pivotally supported at the rotating end of each of the connecting links, and the engine is supported by the vehicle body frame, and at least one of the vehicle body frame and the engine is supported by the vehicle body frame. A vibration isolating device for a vehicle engine, characterized in that an elastic member is interposed between one side and a connecting link.