JPS61157850A - Transmission gear - Google Patents

Abstract

PURPOSE:To absorb sufficiently torque variation while restraining rapidly free vibration to prevent a car body from fore-and-aft vibration by providing a spiral spring and a vibration damping member between a crankshaft and an input shaft of a transmission. CONSTITUTION:A spiral sprig 10 is provided between a crankshaft 1 and an input shaft 3 of a transmission 4, and when a clutch is turned on, power is transmitted from the crankshaft 1 to the input shaft 3 through a clutch disk 13 and the spiral spring 10. Then, torque variation is damped by the spiral spring 10. Also, between the crankshaft 1 and the input shaft 3 is provided a vibration damping member generating solid frictional resistance due to a frictional plate 16.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a power transmission system for an automobile that prevents deterioration in riding comfort caused by torque fluctuations of an internal combustion engine.

BACKGROUND OF THE INVENTION A power transmission device for an automobile transmits power from a flywheel attached to the crankshaft of an internal combustion engine to a drive axle via a clutch mechanism, a transmission, a propeller shaft, a final stage reduction gear, and the like. If the torque fluctuations caused by the explosive force and inertial force of the internal combustion engine 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 occupants. A large portion of the torque fluctuation is absorbed by the moment of inertia and elastic deformation of each part (for example, see "Automotive Engineering Complete Book Volume 9'," published by Sankaido, November 2010, Showatei).

In addition, in Special Publication No. 54-21, the flywheel is
a first flywheel fixed to the crankshaft;
A configuration is disclosed in which the clutch mechanism is divided into a second flywheel and a second flywheel to which a clutch mechanism is attached, and a spiral spring is interposed between the two to absorb the strain caused when the clutch is connected.

Problems to be Solved by the Invention However, in the conventional power transmission device described above, each part has high rigidity and there is very little deflection due to elastic deformation, so the absorption of torque fluctuation is incomplete, and the Ck Uncomfortable longitudinal G occurs. Moreover, 40Hz
At the above level, the drive axle has the greatest effect of absorbing torque fluctuations due to elastic deformation, but since this drive axle has almost no pulsation damping capacity, the damping capacity of the entire system is insufficient.
Free vibrations in the system that occur due to sudden changes in driving force due to sudden acceleration, etc., do not dampen easily and become a cause of vehicle body vibration.

In the device described in Japanese Patent Publication No. 54-21, the flywheel is divided into two parts, so it becomes a two-degree-of-freedom system and two-node vibration occurs, and the resonance frequency is around 30H2. appear. As a result, the engine speed is 600 to 900.
This corresponds to the rotational secondary vibration around the rpm, and there is a risk of severe vibration occurring when the clutch is engaged at a low rotational speed and the vehicle is started.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a system between the crankshaft of an internal combustion engine and the transmission input shaft, which is displaced by the rotational force between the two. It is characterized by interposing a spring and providing a vibration damping member that generates solid frictional resistance or viscous resistance sound between the two.

Action Figure 8 (al represents a simplified model for studying the vibration characteristics of the power transmission device. Iw is the moment of inertia of the flywheel of the rotating part of the engine, Kc,
Cc is the torsion spring constant damping coefficient of the clutch mechanism installed between the flywheel and transmission, and K8 is the torsion spring constant from the transmission to the drive wheel converted to the flywheel axis position. It is expressed as throat spring constant of Ke middle axle/(total reduction ratio b)2. Note that the damping coefficient of this portion is substantially O. Further, I) l is a value obtained by converting the vehicle mass to the flywheel axis position, and is IB = My''/i (where M: vehicle mass, D: effective radius of tire, i: total reduction ratio).

In the conventional case, the amplitude of the torque applied when Teasωt is applied is as shown by the curve 1 in FIG. 9. This was obtained by calculating the degree of relaxation due to deflection from actual vehicle values.89 The vertical axis represents the excitation force transmission rate when the spring constant is ω ( =□11□). In this way, in the conventional configuration, LOH
There is a large resonance peak around 2, and even in the 40 to 50 Hz region, which corresponds to the low speed range of 1200 to 1500 rpm in a 4-cylinder engine, it is not possible to sufficiently buffer the 9 forced vibrations due to torque fluctuations. .

On the other hand, in the present invention, by using a spiral spring, Kc f can be made to a sufficiently small value, and as a result, the resonant frequency can be reduced to 1.3 Hz, as shown by curve 2 in FIG.
At the same time, free vibration at the resonant frequency is suppressed by the small damping coefficient Oc. At the same time, forced vibrations in the 40 to 50 Hz range are also sufficiently damped.

Curve 3 is shown in Fig. 8(b), with the flywheel 2
This shows the case where the coil spring is divided into parts and a spiral spring is installed between them, and as mentioned above, the peak value is mainly at about 21 Hz, which has unfavorable characteristics.

In addition, the spring constant Kc is 2000.
If this is the case, the torsion angle will be 8 rad, or approximately 1.3 rotations, when the engine maximum torque clutch is 16# and false, and such a spring constant cannot be achieved without a spiral spring.

Embodiment FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
3 indicates the crankshaft 7) of the internal combustion engine 2, and 3 indicates the input shaft of the transmission 4, both of which are kept coaxial by the fitting portion 5.
'are doing. 6 is a drive plate that is equipped with a ring gear 7 on its outer periphery, and bolts 8 are attached to this drive plate 6.
A hollow housing 9 is fixed by. 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. It matches. Reference numeral 13 indicates a clutch disk provided to face the inner wall surface of the housing 9 on the internal combustion engine 2 side, and reference numeral 14 indicates a clutch facing.
A roller holding member 15 consisting of a pair of annular plates is provided on the outer periphery of the roller holding member 15.
are attached by engaging each other's claws, and a pair of rollers 16 are attached to the roller holding member 15 at positions 180 degrees apart. In addition, frJ12 other than the above
A pair of rollers 17 are mounted on the side surfaces of the rollers 17 at the same distance of <180', and as shown in FIG. The inner cylinder 11 has radial grooves 19 at its end.
A friction plate 19 with a carved mark a is spline-fitted,
The housing 9 is pressed against the inner wall surface of the housing 9 on the transmission 4 side by the biasing force of a disc spring 20 provided on the rear surface.

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 2
The clutch disc 13 in the housing 9 also communicates with the transmission 4 side via the groove 19a of the friction plate 19, and the lubricating oil discharge passage 22 communicates with the passage 23 in the input shaft 3 and the crankshaft 1 side. The clutch disk 13 in the housing 9 communicates with the internal combustion engine 2 through a passage 24 .

Further, as shown in FIG. 3, in this embodiment, a spiral spring 10
A combination of three spiral springs separated by 120 degrees is used, and in the initial state, a considerable portion of the outer circumferential side is in close contact with each other.

Next, the operation of the above embodiment will be explained.

The housing 9 is always filled with engine lubricating oil through the lubricating oil supply passage 21 fL, but if the lubricating oil discharge passage 22 is closed,
Since no pressure difference is generated before and after the clutch disc 13, a "clutch disconnected" state occurs. 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 10, and the inner cylinder 11 in this order. In this state, torque fluctuations are buffered 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 10 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 in the above-described manner, the eccentricity of the center of gravity can be suppressed as much as possible. In addition, by connecting with the Oldham joint, transmission of centrifugal force due to eccentricity to the vehicle body is prevented.

In addition, the spiral spring IO is displaced in the winding direction when torque is applied in the forward direction of the vehicle, but as shown in Fig. 4, when a torque close to the maximum torque of the engine is applied, the non-contact portion of the spiral spring IO is the most It's meant to be long. In other words, since the parts that are not in close contact with each other are the parts that effectively act on torsion, the longer n is, the smaller the spring constant becomes, and as shown in Figure 5, the amplitude of the excitation force is larger. The higher the load, the smaller the spring constant becomes, making it difficult to obtain the most effective buffering effect within the limited size of the spiral spring 10.

Note that a part of the spiral spring 10 is omitted in FIGS. 3 and 4.

On the other hand, since the friction plate 19 is pressed against the housing 9 by receiving the force of the disc spring 20, and lubricating oil is always supplied between the two through the groove 19a'i, an appropriate viscous damping effect is provided.

Next, the embodiment shown in FIG.
A flywheel 32 is fixed to the end of the flywheel 32, and the outer casing of the spiral spring 10 is attached to the outer periphery of the flywheel 32 via short cylindrical support member wings and a rubber member 34t. There is. The rubber member 34 does not have a bent shape t as shown in FIG. 7, and allows eccentricity of the outer cylinder 12.

In addition, the inner cylinder 11 of the spiral spring 10 is connected to the input shaft 3 through the bushing 3.
They are rotatably fitted through five-metal gold, and a power transmission disk portion 36 is provided at the end. The clutch mechanism 31 is attached to this power transmission disc portion 36, and is connected to the input shaft 3.
A clutch disc having a hub 37 spline-fitted to the clutch disc is designed to come into sliding contact with one surface of the power transmission disc portion. Note that the clutch mechanism 31 has a spiral spring 10 that reduces shock when the clutch is engaged.
Buffer springs etc. are omitted.

Reference numeral 39 denotes a friction member supported by the inner cylinder 11 via a disk 40 made of a spring material, which is pressed against the flywheel 32 by the disk 40 and exerts a capital reduction effect due to solid friction. be.

In this configuration, the clutch mechanism 31 disconnects and connects power between the spiral spring 10 and the input shaft 3, but the intervention of the spiral spring 10 in this power transmission path prevents torque fluctuations. It is buffered and prevents unpleasant vibrations from the car body.

Effects of the Invention As is clear from the above explanation, the power transmission device for an automobile according to the present invention is provided with a spiral spring and a vibration damping member between the crankshaft and the transmission input shaft, so that torque fluctuations are sufficiently suppressed. In addition to achieving excellent absorption, free vibrations can be quickly suppressed, and longitudinal vibrations of the vehicle body that cause discomfort to passengers can be prevented.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the present invention, Figs. 2 and 3 are sectional views taken along lines 11-■ and 1-11[, respectively, and Fig. 4 shows a state where torque is applied. Fig. 5 is a characteristic diagram showing the relationship between torque and displacement of a spiral spring, Fig. 6 is a sectional view showing a different embodiment of the present invention, and Fig. 7 is its 8 (al, (b) is an explanatory diagram showing a modeled system of the power transmission device, and FIG. 9 shows the vibration characteristics of this system between the conventional and the present invention. It is a characteristic diagram showing comparison. l... Crankshaft, 3... Input shaft, 9...
No. crank, 10... spiral spring, 11... inner cylinder,
12...Outer cylinder, 13...Clutch disc, 14.
...Clutch facing, 16, 17...Roller, 18...Connection plate, 19...Friction plate, processing...
・Disc spring, 21... Lubricating oil supply passage, 22... Lubricating oil discharge passage, 31... Clutch mechanism, 32... Flywheel, 34... Rubber member, A... Clutch disc, 39...Friction member. Figure 7

Claims (1)

[Claims] (1) In an automobile power transmission system that extends from the crankshaft of an internal combustion engine to a drive axle via a transmission, a spiral spring is disposed between the crankshaft and the transmission input shaft and is displaced by a rotational force between the two. What is claimed is: 1. A power transmission device for an automobile, characterized in that a vibration damping member is provided to provide solid frictional resistance or viscous resistance between the two.