JPS61278622A - Power transmitting device - Google Patents

Abstract

PURPOSE:To enable effective prevention of a fluctuation in torque, by a method wherein a vibration damping device is situated between crank shaft and the input shaft of a transmission gear, and damping effect is varied depending upon an operation condition: CONSTITUTION:A spiral spring 10 is set such that it is displaced in a winding-in direction when torque is exerted in the advancing direction of a vehicle, and the non-firm adhering part of the spiral spring 10 is expanded to longmost size under a state in that torque near to maximum torque of an engine is exerted. Namely, since portions, not firmly adhered to each other, are a portion effectively working against twist, the more the length of the portion is, the less the constant of the spring is. Thus, with the progress of a high load in that amplitude of an exciting force is high, the constant of the spring is de creased, and a most effective buffering effect can be produced within the limited size of the spiral spring 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a power transmission device that attenuates and absorbs torque fluctuations in an internal combustion engine of an automobile or the like.

“(Prior art) The power transmission device of an automobile is 1For example, November 1980
As described in "Automotive Engineering Complete Book No. 9 @ Power Transmission Device" published by Sankaido, from the flywheel attached to the crankshaft during the internal combustion period, to the clutch mechanism, transmission,
Power is transmitted to the drive axle via the propeller shaft, final stage reducer, etc.

Here, if the torque fluctuations caused by the explosive force and inertia force during the internal combustion period are transmitted as they are through the power transmission device, so-called longitudinal G will occur in the vehicle body, causing significant discomfort to the occupant. In reality, much of the torque fluctuation is absorbed by the moment of inertia and elastic deformation of each part.

Furthermore, in Japanese Patent Publication No. 54-21, the flywheel is divided into a first flywheel fixed to the crankshaft and a second flywheel to which a clutch mechanism is attached. A configuration is disclosed in which a spiral spring is interposed to absorb the shock.

(Problem to be solved by the invention) However, in the conventional power transmission device described above, the rigidity of each part is high and there is very little deflection due to elastic deformation, so the absorption of torque fluctuation is incomplete, and especially in low Uncomfortable longitudinal G occurs during rotation.

Moreover, at frequencies above 40 Hz, the drive axle has the greatest effect of absorbing torque fluctuations due to elastic deformation, but since this drive axle has almost no vibration damping capacity, the damping capacity of the entire system is insufficient, and the drive axle due to sudden acceleration, etc. Free vibrations in the system caused by sudden changes in force do not dampen easily, which is still a cause of vehicle body vibration.

On the other hand, in the device described in Japanese Patent Publication No. 54-21, since the flywheel is divided into two parts, it becomes a two-degree-of-freedom system and two-node vibration occurs, and a resonance frequency appears around 20 to 30 Hz.

As a result, in the case of a 4-stroke, 4-cylinder engine, secondary rotational vibrations occur at engine speeds of around 600 to 900 rpm, and there is a risk of severe vibrations occurring when the engine is started at low speed with the clutch engaged.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and in order to achieve this purpose, the present invention provides a method for connecting the transmission from the crankshaft of the internal combustion engine. In a power transmission device that transmits power to a drive shaft via A vibration damping device that generates frictional resistance or viscous resistance is provided, and the vibration damping device is provided with a vibration damping control device that detects operating conditions of the internal combustion engine and controls the rate of damping.

(Function) Figure 6 shows a simplified model for studying the vibration characteristics of the power transmission device.

Iw is the moment of inertia of the rotating part of the engine and the flywheel, Kc and Cc are the torsional spring constants and damping coefficients of the clutch mechanism etc. installed between the flywheel and the transmission, and Ks is the torsion from the transmission to the drive wheels. This is the spring constant converted to the flywheel shaft position, and is expressed as KsΦ axle torsion spring constant/(total 'reduction ratio i)2. Note that the damping coefficient of this portion is substantially 0. In addition, IB is the value obtained by converting the vehicle mass to the flywheel axis position, and I n
= M r'/i (where M: vehicle mass, r: when external force (torque) TCO5ωt is applied to the effective half Iw of the tire, the amplitude of the torque applied to In is as shown in the curve ■ in Figure 7 in the conventional model. This is obtained by calculating the degree of relaxation due to deflection from the actual value of the vehicle, and the vertical axis indicates the value obtained by dividing the transmission rate of the excitation force by the spring constant.

In this way, in the conventional configuration, there is a large resonance peak around 1OH2, and in a 4-stroke, 4-cylinder internal combustion engine, 1
40~ which corresponds to the low speed range of about 200~1500rpm
Even with acceleration in the 50 Hz range, it is not possible to sufficiently dampen forced vibrations caused by secondary torque fluctuations in engine rotation.

On the other hand, in the device of the present invention, by using an elastic member such as a spiral spring, Kc can be set to a sufficiently small value of 9, and as a result, the damping coefficient Cc in FIG. 7 is 100.
As shown by the curve (■), the resonant frequency can be lowered to about 1.8 Hz, and the free vibration at the resonant frequency is suppressed by the small damping coefficient Cc, and at the same time, the forced vibration in the 40 to 50 Hz region is suppressed. Vibrations are also sufficiently damped.

Further, in the device of the present invention, by providing the vibration damping control device, the damping coefficient Cc can be selected depending on the operating conditions of the internal combustion engine.

For example, as shown in curves (2) and (2), when the damping coefficient Cc is slightly increased, the forced vibration tends to increase somewhat, but the free vibration level at the resonant frequency decreases.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In describing this embodiment, an automobile power transmission device will be taken as an example.

First, the configuration of the embodiment will be explained.

Reference numeral 1 indicates a crankshaft of an internal combustion engine 2, and reference numeral 3 indicates an input shaft of a transmission 4. Both shafts 1 and 3 are kept coaxial by a fitting portion 5.

Reference numeral 6 denotes a drive plate having a ring gear 7 on its outer periphery, and a hollow I\Using 9 is fixed to this drive plate 6 with bolts 8.

The spiral spring 10 housed in the housing 9 has an inner peripheral end and an outer peripheral end fixed to an inner cylinder 11 and an outer cylinder 12, respectively, and the inner cylinder 11 is spline-fitted to the input shaft 3. .

Reference numeral 13 denotes a clutch disk provided to face the inner wall surface of the housing 9 on the internal combustion engine z side, 14 a clutch facing, and the clutch disk 13 and the holder 16 are coaxial.

Note that a claw 90 provided on the clutch disc 13 fits into a hole 91 of the holder 16, and the clutch disc 13 is coaxial with the holder 16, movable in the axial direction, and rotates in the same phase.

The holder 16 is maintained coaxially with the crankshaft 1 by an adapter 92.

The outer cylinder 12 is fixed to the outer circumference of the holder 16 with a pin 17 to maintain coaxiality with the input shaft 3.

Further, a vibration damping device 152 of a wet clutch mechanism is provided at the end of the inner cylinder 11, which presses the friction plate 19 held between the plates 50 by the biasing force of the disc spring 20.

The plate 50 of the vibration damping device 52 is engaged with a ring 54 fixed to the housing 9 with bolts 53, and the inner cylinder 11
The friction plate 19 that meshes with the disc spring 20 is pressed into contact with the friction plate 19 by the biasing force of the disc spring 20.

A stopper 51 is provided on the opposite side of the plate 50 from the disc spring 20, and the ffi spring 20 is in contact with the piston 55.

The piston 55 is disposed in a cylinder 57 having a stopper 56, and is communicated from the cylinder 57 to an oil passage 60 via an oil passage 58 and an oil passage 59 in the input shaft 3.

A stopper 49 is also provided on the cylinder 54 to limit the movement range of the piston 55.

Further, a lubricating oil supply passage 21 and a lubricating oil discharge passage 22 are formed at the end of the transmission 4, and the lubricating oil supply passage 21 is connected to the clutch disc 13 in the housing 9 through passages 18a and 18b. connected to the machine 4, and
The lubricating oil discharge passage 22 communicates with the internal combustion engine 2 rather than the clutch disc 13 within the housing 9 via a passage 23 within the input shaft 3 and a passage 24 on the crankshaft l side.

Moreover, as shown in FIG.
A combination of three spiral springs separated by 120 degrees is used as O, and in the initial state (FIG. 3), a considerable portion of the outer circumferential side is in close contact with each other.

Furthermore, the oil pipe 60 of the vibration damping device 52 is provided with a vibration damping control device 100 that generates hydraulic pressure in conjunction with a throttle valve, as shown in FIG.

This vibration damping control device 100 includes a plate 62 that abuts a link 61 that moves in conjunction with a throttle valve (not shown), a piston 64 that is connected by a shaft 63, and a cylinder 65 that houses the piston 64.

The cylinder 65 is provided with a stopper 66 and an O-ring 67, and a spring 68 urges the plate 62 to the right in FIG.

A check valve 72 having an orifice 71 communicates with a first cylinder 73 of the cylinder 65 via an oil passage 70 from the oil tank 69 .

Also, the orifice 75 is connected from the oil tank 69 via the oil pipe 74.
The check valve 76 having the second cylinder 7 of the cylinder 65
It is connected to 7.

Also, a check valve 80 having an orifice 79 that communicates from the first cylinder 73 via an oil pipe 78 connects to the oil pipe 60.
Further, a check valve 83 having an orifice 82 that communicates with the second cylinder 77 via an oil passage 81 also communicates with the oil passage 60 .

Note that these check valves 72, 76, 80, 83 flow in the direction of the arrow in Figure 2, and the orifice 71, 75 flows in the opposite direction.
, 79.82.

Next, the operation of the embodiment will be explained.

Engine lubricating oil continues to be fed into the housing 9 through the lubricating oil supply passage 21 and is filled with lubricating oil, but if the lubricating oil discharge passage 22 is closed, the engine lubricating oil continues to be fed into the housing 9 through the lubricating oil supply passage 21, but if the lubricating oil discharge passage 22 is closed, Since no differential pressure is generated, the clutch becomes "disengaged". At this time, the housing 9 and the lubricating oil therein function similarly to a flywheel.

When the lubricating oil discharge passage 22 is opened in conjunction with the driver's clutch operation, the oil pressure between the clutch disc 13 and the housing 9 decreases, and the clutch disc 13 is pressed against the housing 9 due to the differential pressure across the front and rear. The clutch is in the "clutch engaged" state. As a result, power is transmitted from the crankshaft 1 to the input shaft 3 through the clutch disc 13, the spiral spring lO1, and the inner cylinder 11 in sequence. In this state, torque fluctuations are damped by the intervention of the spiral spring 10, as described above. Further, the shock when the clutch is engaged is also buffered by the spiral spring 10.

As a result of the spiral spring lO being displaced in accordance with the magnitude of the torque of the engine, its center of gravity also becomes eccentric, but by combining a plurality of spiral springs as described above, the eccentricity of the center of gravity is suppressed as much as possible.

Moreover, the spiral spring 10 is displaced in the winding direction when torque is applied in the forward direction of the vehicle, but as shown in FIG. is the longest.

In other words, the parts that are not in close contact with each other are the parts that effectively act on torsion, so the longer they are, the smaller the spring constant will be, and the more the amplitude of the excitation force is high and the load is high, the smaller the spring constant will be. The most effective buffering effect can be obtained within the limited size of the spiral spring 10. Note that a part of the spiral spring 10 is omitted in FIG. 3.4.

In this way, in the power transmission device using the spiral spring 10,
As shown in the characteristics marked ■ in Figure 9, in vehicles using a 4-stroke, 4-cylinder engine, secondary rotational vibrations (in the tens of Hz range) during steady operation and free vibrations that occur around 10 Hz are significantly reduced. However, as the level of the natural frequency of 1 to several Hz increases, and the frequency is 1 to several Hz, it is easy to get sick, and it is desirable to improve it further.

Therefore, during steady running, the action of the vibration damping device 52 is made small to obtain the characteristic (2) with a small damping coefficient Cc, and vertically unbalanced rotation caused by the torque generated by the explosion or the inertial force of the reciprocating part. In addition to reducing secondary vibrations, when accelerating or decelerating due to rapid accelerator operation, the vibration damping device 52 is made to work more and the damping coefficient Cc is made larger.
By preventing low frequency free vibration of 1 to several Hz, free vibration is reduced.

In steady operation with the accelerator held constant, most of the excitation force of the engine is secondary rotational components and no low-frequency vibrations occur, but if the torque suddenly changes due to the opening and closing of the accelerator, this will cause sparkles and cause vibrations. Vibration occurs.

In other words, in Fig. 2, during rapid acceleration, link 6
1 suddenly pushes the plate 62 to the left, and the piston 64 connected by the shaft 63 against the spring 68 is also suddenly pushed.

Therefore, the oil in the first cylinder 73 passes through the oil pipe 78, the check valve 80, the oil pipe 60°59.58, and flows into the cylinder 57-, against the disc spring 20. Push the piston 55 to the left.

Then, the sliding between the plate 50 and the friction plate 19 becomes small due to the pressing force of the piston 55, and the moment the accelerator is suddenly depressed, the disc spring 20 strongly pinches the friction plate 19 and the damping force becomes large, and the damping coefficient Cc becomes large. becomes.

Due to the above-mentioned action, from the characteristics of ■ shown in Figure 9, ■further ■
The characteristic changes to the characteristic of the cylinder 57, lowering the peak of the natural frequency (1 to several Hz) and reducing the occurrence of free vibration. The amount of oil decreases, the piston 55 slowly moves to the right, and the damping force becomes smaller.

Then, it becomes possible to absorb the secondary torque fluctuations of the engine rotation during steady running, and to introduce stable drive characteristics to the output shaft side.

In addition, since the volume of the second cylinder 77 increases rapidly during this rapid acceleration, oil is caused to flow from the oil tank 69 via the oil amount 74 and the check valve 76 .

Further, during rapid deceleration, the link 61 is pulled to the right in FIG. 2, and the piston 64 is pulled to the right by the force of the spring 68 that presses the plate 62.

Then, as in the case of sudden acceleration, the oil in the second cylinder 77 flows into the cylinder 57 through the check valve 83 and through the oil amount 60,59. Press against 20.

Due to such an operation, the damping coefficient Cc increases as in the case of rapid acceleration, and the occurrence of free vibrations of 1 to several Hz is suppressed.

Additionally, over time, oil flows through the orifice.
, 71.75, the amount of oil in the cylinder 57 decreases, the piston 55 slowly moves to the right, and the damping coefficient Cc
is small (■→■→■ in Fig. 9), which is a characteristic that is effective in reducing the second-order component per revolution.

When the piston 64 rapidly moves to the right, the first cylinder 73 is supplied with oil from the oil tank 69 via the check valve 72 .

When the link 61 and the plate 62 are separated, the plate 62 is biased to the right by the spring 68, and the piston 64 hits the stopper 66 and stops. On the other hand, if the piston 64 moves too much even during rapid acceleration, a large amount of oil will be sent from the oil amount 60 to the cylinder 57, so a stopper 84 is provided at an appropriate position.

On the other hand, the piston 55 is urged by the disc spring 20.

When the oil pressure in the cylinder 57 decreases, the cylinder 57 comes into contact with the stopper 56, resulting in a state (2) where the damping coefficient Cc is the smallest.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention may be modified even if there are design changes within the scope of the gist of the present invention. included.

For example, in the embodiment, a device using a spiral spring has been described, but even if the damping coefficient Cc for the damper spring of a normal clutch is controlled to increase or decrease depending on engine operating conditions, steady operation, sudden acceleration, and sudden deceleration are possible. Of course, it is effective in reducing vibrations during operation.

In addition, although a spiral spring is shown as an elastic member in the embodiment,
As mentioned above, other elastic members may be used as long as they have predetermined torsional characteristics, such as the damper spring of the clutch.

In addition, in the embodiment, an example was explained in which control is performed using a signal related to the throttle opening as an engine operating condition, but signals such as engine suction negative pressure, rotation, torque, vibration, etc. can be taken in directly or as an electric signal, and the determination circuit can be controlled. A similar effect can be expected even if the torsional damping is controlled to increase or decrease using a control device including the above.

(Effects of the Invention) As is clear from the above description, the power transmission device according to the present invention includes an elastic member, a vibration damping device, and a vibration damping control device between the crankshaft and the transmission input shaft. Since the damping effect is made variable depending on the engine operating conditions, torque fluctuations can be absorbed and free vibrations suppressed most effectively depending on the engine operating conditions, and the longitudinal vibration of the vehicle body that causes discomfort to the passengers can be reduced. The effect is that it can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the device of the present invention, Fig. 2 is a sectional view showing a vibration damping control device of the embodiment device, Fig. 3 is a sectional view taken along line I-I in Fig. 1, and Fig. 4 is a cross-sectional view similar to FIG. 3 in a state where torque is applied, FIG. 5 is a characteristic diagram showing the relationship between torque and displacement of the spiral spring, and FIG. 6 is a modeled explanation of the power transmission system. 7 are characteristic diagrams showing a comparison of the vibration characteristics of this system between the conventional system and the present invention. 1... Crankshaft 3... Input shaft (transmission input shaft) 10... Spiral spring (elastic member) 52... Vibration damping device

Claims (1)

[Scope of Claims] 1) In a power transmission device that transmits power from the crankshaft of an internal combustion engine to a drive shaft via a transmission, a rotation direction between the crankshaft and the transmission input shaft is provided. A vibration damping device that generates solid frictional resistance or viscous resistance between both shafts is provided in addition to an elastic member that is displaced by force, and the vibration damping device detects the operating conditions of the internal combustion engine and determines the damping rate. A power transmission device characterized by being provided with a vibration damping control device that controls. 2) The vibration damping control device is a device that detects a signal related to the rate of change of the throttle valve as an operating condition of the internal combustion engine, and controls the damping ratio based on this detection signal. power transmission device.