JPH0514027Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a balancer device for an internal combustion engine that reduces vibration and noise of the engine.

(Prior art) Conventionally, as an effective means for reducing vibrations and noise that occur when the engine rotates at low speeds, an additional weight rotating body that rotates in the opposite direction to the rotation direction of the engine crankshaft has been added to the crankshaft. A so-called balancer device is widely known that cancels out the rotational moment of inertia generated in the rotational direction of the crankshaft and reduces vibration and noise by generating a rotational moment of inertia in the opposite direction to the rotational moment of inertia generated in the rotational direction of the shaft. ing.

(Problem to be solved by the invention) However, although such conventional balancer devices can effectively reduce vibration and noise when the engine is running at low speeds, when the engine is running at high speeds, the additional weight of the rotating body is This has the disadvantage that it becomes a resistance and becomes a factor that limits the maximum engine speed and impairs the engine's ability to rev up.

Further, in order to rotate the additional weight rotating body in the opposite direction to the crankshaft, a special device such as an idler gear or roller interposed between the additional weight rotating body and the flywheel is required.

The present invention was developed to eliminate such inconveniences; it reduces engine vibration and noise when the engine speed is low and does not reach a predetermined speed, and at the same time reduces the rotational inertial mass of the crankshaft system when the engine speed is high. To provide a balancer device for an internal combustion engine, which increases the maximum rotational speed of an engine, improves engine revving, and has a simple configuration.

(Means for solving the problem) According to the present invention, in order to achieve the above purpose,
A main flywheel fixed to the shaft end of the crankshaft, a sub flywheel rotatably arranged concentrically with the main flywheel, and a sub flywheel interposed between the main flywheel and the sub flywheel, A clutch device is provided, which engages the sub flywheel with the main flywheel and rotates it together with the main flywheel when the rotation speed is low and does not reach a predetermined rotation speed, and is attached to one end of the rotating shaft of the starter. The pinion gear is engaged with the ring gear of either the main flywheel or the auxiliary flywheel when starting the engine, and is engaged with the ring gear of the auxiliary flywheel at times other than when starting the engine, and is engaged with the ring gear of the auxiliary flywheel when starting the engine. There is provided a balancer device for an internal combustion engine, characterized in that an additional weight rotating body is attached to the other end and the additional weight rotating body is rotated in a direction opposite to the direction of the calanque shaft.

(Function) The clutch device of the balancer device for an internal combustion engine of the present invention engages the auxiliary flywheel and the main flywheel when the engine speed is low and does not reach a predetermined speed, and rotates them integrally and in the same direction. When the engine speed is higher than the predetermined number, the sub flywheel is separated from the main flywheel and only the main flywheel is rotated. On the other hand, when starting the engine, the starter pinion gear engages with the ring gear of either the main flywheel or the sub-flywheel to start the engine, and at other times, it engages with the ring gear of the sub-flywheel to start the engine. The rotation of the auxiliary flywheel at low rotation speeds is transmitted to the additional weight rotating body via the rotating shaft. At this time, the additional weight rotating body rotates in a direction opposite to that of the auxiliary flywheel and therefore the crankshaft, thereby canceling out the moment of inertia generated in the direction of rotation of the crankshaft, thereby reducing vibration and noise.

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

1 and 2 show a first embodiment of the present invention, in which a main flywheel 2 is fixed to a shaft end 1a of a crankshaft 1 of an engine (not shown). A ring gear 3 is engraved on the outer circumferential surface of the main flywheel 2. The main flywheel 2 can be engaged with a ring-shaped secondary flywheel 5 via a known centrifugal clutch 4, and the secondary flywheel 5
The outer circumferential surface of the main flywheel 2 has a ring gear 6 having the same outer diameter as the ring gear 3 of the main flywheel 2, and the inner circumferential surface of the main flywheel 2 is rotatably supported by a bearing 7.

The centrifugal clutch 4 (Fig. 2) has a shoe 4 on its inner peripheral surface.
centrifugal weight 4b to which a is attached, and spring 4c
It consists of One end of the centrifugal weight 4b is connected to the pin 4
The spring 4c is rotatably supported by the side surface 2a of the main flywheel 2 on the side of the sub-flywheel 5 through Peripheral wall 2
b, and the other end is locked to the substantially central back surface of the centrifugal weight 4b, and the centrifugal weight 4b is pressed against the outer circumferential wall 5a of the inner circumferential edge step portion of the sub flywheel 5 that protrudes toward the main flywheel 2 side. are doing. A predetermined number of centrifugal clutches 4 configured in this manner are arranged at equal positions on the circumference.

Reference numeral 10 denotes a starter, and a pinion gear 13 is provided at one end 11a of the rotating shaft 11 of the starter 10, and is spline-coupled to rotate integrally with the rotating shaft 11 and slidably in the axial direction. is selectively engaged with the ring gears 3 and 6 of the main flywheel 2 and the sub flywheel 5 by a shift fork 14. A shift fork 14 that is engaged with a pinion gear 13 swings around a pin 15 by an electromagnetic coil 16 and a return spring 17. Rotating shaft 1 of starter 10
1, an additional weight rotating body (hereinafter simply referred to as "additional mass") 20 is fixed to the other end 11b of the rotary shaft 11, and the additional mass 20 rotates together with the rotating shaft 11. still,
This additional mass 20 is formed into a desired shape and weight so as to cancel the inertial rotation moment of the crankshaft 1 when the engine rotates at low speeds and reduce vibration and noise.

Next, the operation of the balancer device configured as described above will be explained.

First, the operating principle of the balancer device of the present invention will be explained. The operating principle of the balancer device of the present invention is as shown in FIG. This can be explained using a torque balancer device having an equivalent structure, in which a belt is used to connect an additional mass and an additional mass with a belt.

Now, M1: Engine generated torque applied from the engine to the flywheel system, M0: Torque transmitted to the drive shaft system after the flywheel system, I1: Inertia of the flywheel system (including the main flywheel 2 and sub-flywheel 5) Moment, I2: Additional mass system (including pinion gear 13, starter motor 10, additional weight rotating body 20, etc.)
Moment of inertia, r1: flywheel drive radius, r2: additional mass system drive radius (corresponds to the radius of pinion gear 13), F: flywheel drive circumferential driving force, and the direction of rotation is the engine rotation. Assuming that the direction is positive, the equation of motion around the center of the main flywheel (O1) is obtained by the following equation (1).

M1=I1・θ¨1+F・r1+M0...(1) Here, θ¨1 is the rotational angular acceleration (rad/s ² ) of the flywheel.

Here, F・r2=±I2・θ¨2, θ¨2=±(r1/r2)θ¨1 (+: forward rotation, -: reverse rotation), F=(I2・r1/r2 ² )・θ¨1...(2) Substituting equation (2) into equation (1), M1=(I1+ρ ²・I2)θ¨1+M0...(3) ρ=r1/r2 (pulley ratio)...( 4) As is clear from equation (3), the moment of inertia of the additional mass system is multiplied by the square of the pulley ratio and can be considered equivalent to that of the flywheel system.

On the other hand, the rolling moment M _B that acts on the engine block is as follows: 1 O1 has a reaction force (-F) of the force that tries to rotate the additional mass system, 2 O2 is attracted by the tangential force on the outer circumference of the flywheel. A force F (same magnitude and opposite direction as above) acts. 3 The couple generated by these two forces is F・(r1〓r2) (here, -: normal rotation,
+: Reverse), so it can be found using the following equation (5).

M _B = −M1+F・(r1〓r2) ……(5) Substituting formulas (2) and (3) into formula (5), M _B =−{I1±(r1/r2)・I2}θ ¨1−M0 ...(6) When M0 = 0 when there is no load, that is, when the engine speed is below a predetermined speed, approximately at idle, the ratio of the rolling moment acting on the engine block to the engine generated torque (rolling moment ratio ) is determined by the following equation (7).

−M _B /M1＝（I1±ρI2）/（I1＋ρ ² I2） ……(7) where + is forward rotation, − is reverse rotation.

From the result of equation (7), the moment of inertia of the additional mass system is
If I2 is (1/ρ) times the flywheel moment of inertia I1, then the rolling moment acting on the engine block can be eliminated by reversing this additional mass.

Therefore, the balancer device will be operated as follows.

First, when a starter switch (not shown) is turned on, the electromagnetic coil 16 is energized, swings the shift fork 14 against the spring force of the return spring 17, moves the pinion gear 13 to the right in the drawing, and moves the main flywheel 2. mesh with ring gear 3. As a result, the rotation of the starter 10 is transmitted to the crankshaft 1 via the main flywheel 2, and the engine is started. When the engine starts and enters self-sustaining operation, the power to the starter 10 is cut off, and the pinion gear 13 is transferred to the ring gear 6 of the sub flywheel 5 by the spring force of the return spring 17.
Move to the position where it engages.

On the other hand, as the engine speed increases, the centrifugal weight 4b of the centrifugal clutch 4 attempts to rotate outward in the radial direction about the pin 4d due to the centrifugal force corresponding to the engine speed, but when the engine speed increases, When the rotation speed is low, the pressing force of the spring 4c causes the centrifugal clutch 4 to rotate the sub flywheel 5 integrally with the main flywheel 2 while keeping the main flywheel 2 and the sub flywheel 5 engaged. Therefore, the rotation of the crankshaft 1 is transmitted to the additional mass 20 via the main flywheel 2, the auxiliary flywheel 5, and the pinion gear 13, causing the additional mass 20 to rotate. At this time, the additional mass 20 rotates in the opposite direction to the rotational direction of the crankshaft 1, and generates a reverse rotational moment of inertia that cancels the rotational moment of inertia of the crankshaft 1.

When the engine speed exceeds the predetermined speed, the centrifugal force acting on the centrifugal weight 4b overcomes the pressing force of the spring 4c, causing the centrifugal weight 4b to rotate and engage the main flywheel 2 and the sub flywheel 5. Release. Therefore, at high speeds, the rotation of the crankshaft 1 is controlled by the auxiliary flywheel 5 and the additional mass 2.
0 is no longer transmitted, and the related mass of the crankshaft system is reduced.

FIG. 3 shows a second embodiment of the present invention, in which components having substantially the same functions as corresponding components in FIG. 1 are given the same reference numerals. In the second embodiment, the main flywheel 2' and the sub-flywheel 5' are connected and disconnected by an electrode clutch 25, and the ring gear 6 provided on the outer peripheral surface of the sub-flywheel 5' is constantly meshed with the pinion gear 13 of the starter 10. are doing. The electromagnetic clutch 25 is attached to a clutch plate 26 fixed to the main flywheel 2' and to the inner circumferential surface of the sub flywheel 5' so as to be slidable only in the axial direction, and is integrated with the sub flywheel 5'. A clutch plate 27 rotates and is pressed by a spring (not shown) to frictionally engage with the main flywheel side clutch plate 26, and when biased, the clutch plate 27 is biased against the pressing force of the spring, and the clutch plate 2
Electromagnetic solenoid 28 that releases the engagement of 6 and 27
It consists of

The electromagnetic solenoid 28 of the electromagnetic clutch 25 is connected to a control circuit (not shown), and similarly to the centrifugal clutch 4 of the first embodiment shown in FIGS. When the rotation speed is reached, the power is deenergized at low rotation speeds, and the main flywheel 2' and the sub flywheel 5' are rotated together while the main flywheel 2' and the sub flywheel 5' are engaged with each other. Therefore, the rotation of the crankshaft 1 is transmitted to the additional mass 20 via the main flywheel 2', the auxiliary flywheel 5', and the pinion gear 13.
Due to the rotation in the opposite direction to that of the crankshaft 1, a reverse rotational moment of inertia is generated which reduces vibration and noise at low rotation speeds.

On the other hand, when the engine speed exceeds the predetermined speed, the electromagnetic solenoid 28 is energized and the clutch plates 26 and 27 are disengaged. As a result, the rotation of the crankshaft 1 at high speeds is not transmitted to the additional mass 20, and the inertial mass of the crankshaft system is reduced.

In the second embodiment as well, the starter 10 is turned on only when starting the engine and generates starting torque to start the engine.

(Effects of the invention) As detailed above, according to the balancer device for an internal combustion engine of the present invention, the clutch device engages the sub flywheel with the main flywheel only when the engine speed is low and does not reach a predetermined speed. When starting the engine, the pinion gear attached to one end of the rotary shaft of the starter is engaged with the ring gear of either the main or sub flywheel to start the engine, and when starting the engine, Sometimes, the pinion gear is engaged with the ring gear of the auxiliary flywheel, an additional weight rotating body is attached to the other end of the starter's rotating shaft, and the added weight rotating body is rotated in the opposite direction to the crankshaft. By using this method, an additional weight rotating body can be installed, which makes it possible to reduce engine vibration and noise at low speeds with a simple configuration.In addition, at high speeds, the rotational inertial mass of the crankshaft system is reduced, and the engine Improve the maximum rotation speed,
Moreover, it has the effect of improving engine revving.

[Brief explanation of the drawing]

1 is a partially sectional configuration diagram showing a first embodiment of a balancer device for an internal combustion engine according to the present invention, FIG. 2 is a partially sectional side view showing details of the centrifugal clutch 4 of FIG. 1, and FIG. FIG. 4 is a partial cross-sectional configuration diagram showing a second embodiment of the balancer device for an internal combustion engine according to the present invention, and FIG. 4 is a schematic configuration diagram for explaining the operating principle of the balancer device of the present invention. 1... Crankshaft, 2, 2'... Main flywheel, 3, 6... Ring gear, 4... Centrifugal clutch, 5, 5'... Sub-flywheel, 10
... Starter, 11 ... Rotating shaft, 13 ... Pinion gear, 20 ... Additional weight rotating body.

Claims (1)

[Scope of utility model registration request] A main flywheel is fixed to the shaft end of the crankshaft, a sub-flywheel is rotatably arranged concentrically with the main flywheel, and a sub-flywheel is interposed between the main flywheel and the sub-flywheel. a clutch device that engages the auxiliary flywheel with the main flywheel and rotates it together with the main flywheel when the number of rotations is low and does not reach a predetermined number of rotations; The pinion gear is engaged with the ring gear of either the main flywheel or the auxiliary flywheel when the engine is started, and is engaged with the ring gear of the auxiliary flywheel at times other than when starting the engine, and is engaged with the ring gear of the auxiliary flywheel when the engine is started. A balancer device for an internal combustion engine, characterized in that an additional weight rotating body is attached to an end thereof, and the additional weight rotating body is rotated in a direction opposite to the crankshaft.