JPH08261290A - Reducing device for vibration of engine - Google Patents

Abstract

PURPOSE: To provide a vibration reducing device which is simple in structure and does not enlarge load. CONSTITUTION: An elliptical guide rail 2 is attached to a crankshaft 1, and a balance weight 3 is reciprocatably supported by a support part 4 formed in an engine body. A pair of shafts 5 is fixed to the balance weight 3, and a roller 6 is severally rotatably attached to the shafts 5, and rotates on the guide rail 2. The balance weight 3 reciprocates twice for one rotation of the crankshaft 1 to generate inertia force to deny the excitation force of the secondary vibration of the engine. The above inertia force can correspond to the vibration composed of the excitation forces having different order by altering the shape of the guide rail.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine vibration reducing device.

[0002]

2. Description of the Related Art In a reciprocating internal combustion engine having a piston and a crank mechanism, vertical vibrations due to inertial force due to the mass of a reciprocating portion such as a piston and lateral vibrations due to swinging of a connecting rod occur. Therefore, in order to prevent the vibration generated by these internal combustion engines from being transmitted to the body member on which the internal combustion engine is mounted, the vibration is absorbed by the mount member between the internal combustion engine and the body member. However, when the mounting member alone cannot absorb the vibration, it is necessary to reduce the vibration itself generated by the engine. Therefore, it is known that the balancer weight is driven by a crankshaft to reciprocate to cancel the vibration generated by the mass of the reciprocating portion of the engine (JP-A-3-33534, JP-A-62-1).
59826).

[0003]

However, in the device of the above-mentioned Japanese Patent Laid-Open No. 3-33534, since the spring is used, the balancer weight is reciprocally moved against this, so that the load is increased. On the other hand, in the apparatus disclosed in Japanese Patent Laid-Open No. 62-159826, there is a problem in that both the cam shaft and the crank shaft need to be provided with cams for driving the balancer weight, which makes the structure complicated. In view of the above problems, it is an object of the present invention to provide a vibration reduction device that has a simple structure and does not increase the load.

[0004]

According to a first aspect of the present invention, there is provided a guide rail which rotates integrally with a crankshaft of an engine, and a sliding contact means which slidably contacts with the guide rail. A balancer weight that is reciprocally attached to the engine, and the guide rail has a track that reciprocates in a phase that cancels the vibration generated by the engine with the rotation of the crankshaft. A featured engine vibration reduction device is provided.

According to a second aspect of the present invention, a true circular ring gear that rotates integrally with the crankshaft of the engine and has teeth formed on the inner and outer peripheral surfaces, and the inner and outer peripheral surfaces of the ring gear. Having a pair of guide gears that mesh with the teeth formed on the balance gear and a balancer weight that is reciprocally attached to the engine in the direction of vibration to be reduced, and the pair of guide gears are rotated by the crankshaft. There is provided an engine vibration reducing device having a pitch curve that causes the balancer weight to reciprocate in a phase that cancels vibration generated by an engine.

[0006]

According to the first aspect of the present invention, when the guide rail rotates integrally with the crankshaft, the balancer weight is reciprocated via the sliding contact means so as to cancel the vibration generated by the engine.

According to the second aspect of the present invention, when the ring gear rotates integrally with the crankshaft, the balancer weight is reciprocated so as to cancel the vibration generated by the engine via the guide gear.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a view of the structure of the first embodiment as viewed from the crankshaft direction, and FIG. 2 is a view of the structure as viewed from a direction perpendicular to the crankshaft. A guide rail 2 is integrally attached to the crankshaft 1. On the other hand, the balancer weight 3 is reciprocally supported by a support portion 4 formed on the engine body (not shown). A pair of shafts 5 is fixed to the balancer weight 3, and rollers 6 are attached to the shafts, respectively.
Is rotatably attached, and the roller 6 rotates on the guide rail 2.

In the first embodiment, the guide rail 2 has an elliptical shape, and in FIGS. 1 and 2, the solid line indicates that the major axis is perpendicular to the reciprocating direction of the balancer weight 3. This is the case, and the case indicated by the broken line is the case in which they are parallel. Therefore, if the position of the center of gravity of the balancer weight 3 in each of the above cases is W1 and W1 ', the center of gravity of the balancer weight 3 makes two reciprocations between W1 and W1' while the guide rail 2 makes one rotation. , Inertia force is generated at a cycle twice the number of revolutions of the crankshaft.

Therefore, as shown in FIG. 3A, when the engine vibration occurs in the secondary rotation, that is, at twice the number of rotations, the vibration is canceled out in FIG. 3B. If the specifications of the balancer weight 3 are set so that the inertial force shown is generated, the combined force of the two becomes as shown in FIG. Can be eliminated. Since it is the in-line four-cylinder engine that the vibration of the secondary rotation is large as shown in FIG. 3A, this first embodiment is particularly suitable for being applied to the in-line four-cylinder engine. . FIG. 4 schematically shows a state in which the first embodiment is arranged in the central portion of the crankshaft of an in-line four-cylinder engine.

FIG. 5 shows a modified example of the first embodiment, in which the balancer weight 3 is rotatably supported laterally. FIG. 6 shows another modification of the first embodiment, in which the guide rail is attached to the counterweight 7 of a certain cylinder. In the figure, reference numeral 8 is a crank pin, and reference numeral 9 is a connecting rod.
FIG. 7 shows another modification of the first embodiment,
The guide rail is doubled, and the pin 10 is attached to the balancer weight 3 instead of the roller. FIG. 8 shows another modification of the first embodiment, in which the guide rail has an inverted T-shaped cross section, and two rollers are in sliding contact with the inner peripheral side of the guide rail. Note that FIG.
7 and 8 show only the state where the long axis of the guide rail is perpendicular to the vibration direction of the engine.

FIG. 9 is a diagram in which the vibration forces due to the primary vibration and the secondary vibration of the engine are combined when they have a magnitude that cannot be ignored. The dotted line shows the exciting force due to the primary vibration, the broken line shows the exciting force due to the secondary vibration, and the solid line shows the combined exciting force. FIG. 10 shows the shape of the guide rail of another modified example of the first embodiment for generating the inertial force for canceling the combined vibration of FIG.

FIG. 11 is a diagram in which the vibration forces due to the secondary vibration and the fourth vibration of the engine are combined when they have a magnitude that cannot be ignored. The broken line indicates the excitation force due to the secondary vibration, the alternate long and short dash line indicates the excitation force due to the fourth vibration, and the solid line indicates the combined excitation force. FIG. 12 shows the shape of the guide rail of another modification of the first embodiment for generating the inertial force for canceling the combined vibration of FIG. In the figure, the broken line shows a shape for canceling the secondary vibration, and the dashed line shows a shape for canceling the fourth vibration.
What is indicated by the solid line is a combination of these combined vibrations and a shape that cancels the combined vibrational excitation force.

As described above, in the first embodiment, even when the engine is vibrated by a plurality of vibrations of different orders that cannot be ignored, the shape of the guide rail can be easily changed so as to cancel them. Is possible. Further, except for the balancer weight that actually generates inertial force, only the guide rail is provided, and no other drive device is required, so that the increase in weight can be suppressed to the minimum. Further, since no spring is used, the load on the engine is not increased.

FIG. 13 schematically shows the structure of the second embodiment. In FIG. 13, 10 is a perfect ring gear having teeth 10a and 10b on the inner and outer peripheral sides, respectively. On the other hand, the balancer weight 11 has the support portion 4 formed on the engine body (not shown) as in the first embodiment.
It is supported by reciprocating motion. A pair of shafts 12 are fixed to the balancer weight 11, and the shafts 12 are
An oval inner guide gear 13 having teeth 13a on its
An elliptical outer guide gear 14 having teeth 14a is rotatable, and its teeth 13a and 14a are mounted so as to always mesh with the inner peripheral side 10a and the outer peripheral side tooth 10b of the ring gear 10.

The pitch circle indicated by the alternate long and short dash line indicates a state in which the balancer weight 11 is closest to the crankshaft 1 in the reciprocating direction, and W2 indicates the position of the center of gravity of the balancer weight 11 at that time. On the other hand, what is indicated by a broken-line pitch circle is the state where the balancer weight 11 is farthest from the crankshaft 1 in the reciprocating direction, and W2 'indicates the position of the center of gravity of the balancer weight 11 at that time.

Since the center of gravity of the balancer weight 11 reciprocates twice between W2 and W2 'during one revolution of the crankshaft 1, as shown in FIG. 3B, as in the first embodiment. Since a large inertial force is generated, by appropriately setting the mass of the balancer weight 11 and / or the difference between the major axis and the minor axis of the inner guide gear 13 and the outer guide gear 14, the exciting force due to the secondary vibration is generated. Can be canceled.
Then, the inner guide gear 13 and the outer guide gear 14
It is also possible to cancel out a plurality of vibration excitation forces having different orders by properly setting the shape of. Moreover, since the inner guide gear 13 and the outer guide gear 14 become a part of the balancer weight, it is possible to suppress an extra weight increase.

[0018]

According to the present invention, since it is not necessary to drive the balancer weight to rotate about the axis, the number of parts is reduced, extra weight is not increased, and whirling resonance of the axis is newly generated. Nor. Further, since the spring is not used, the load on the engine does not increase. In particular, according to the first aspect, since no gear is used, noise is low, and there are no parts that require complicated processing, so the processing cost is low.

[Brief description of drawings]

FIG. 1 is a diagram showing the structure and operation of the first embodiment.

FIG. 2 is a diagram showing the structure and operation of the first embodiment.

FIG. 3 is a diagram illustrating an action of canceling a vibration excitation force of an engine by an inertial force of a balancer weight.

FIG. 4 is a diagram showing an example of arrangement in the engine of the first embodiment.

FIG. 5 is a diagram showing a structure of a modified example of the first embodiment.

FIG. 6 is a diagram showing the structure of another modification of the first embodiment.

FIG. 7 is a diagram showing the structure of another modification of the first embodiment.

FIG. 8 is a diagram showing the structure of another modification of the first embodiment.

FIG. 9 is a diagram illustrating a vibration excitation force that is a combination of a primary vibration excitation force and a secondary vibration excitation force.

FIG. 10 is a diagram showing the shape of a guide rail that generates an inertial force that cancels the combined vibration excitation force of FIG. 9;

FIG. 11 is a diagram illustrating a vibrational excitation force that is a combination of a secondary vibrational excitation force and a fourth-order vibrational excitation force.

FIG. 12 is a diagram showing the shape of a guide rail that generates an inertial force that cancels the combined vibration excitation force of FIG. 9;

FIG. 13 is a diagram showing a structure of a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Crankshaft 2 ... Guide rail (1st Example) 3 ... Balancer weight (1st Example) 4 ... Support part 6 ... Roller (1st Example) 7 ... Counterweight 10 ... Ring gear (2nd Example) 11 ... Balancer weight (second embodiment) 13 ... Inner guide gear (second embodiment) 14 ... Outer guide gear (second embodiment)

Claims (2)

[Claims] 1. A balancer weight, which has a guide rail that rotates integrally with a crankshaft of an engine, and a sliding contact means that slidably contacts the guide rail, and is reciprocally mounted in the engine in a direction of vibration to be reduced. The engine vibration reduction device according to claim 1, wherein the guide rail has a track that reciprocates the balancer weight in a phase that cancels vibration generated by the engine with the rotation of the crankshaft. 2. A rotary shaft integrally rotating with a crankshaft of an engine,
It has a perfect circular ring gear with teeth formed on the inner and outer peripheral surfaces and a pair of guide gears that mesh with the teeth formed on the inner and outer peripheral surfaces of the ring gear, and reciprocates in the direction of vibration to be reduced. A balancer weight movably attached to the engine, wherein the pair of guide gears has a pitch curve that causes the balancer weight to reciprocate in a phase that cancels the vibration generated by the engine as the crankshaft rotates. Engine vibration reduction device.