JPH1194024A - Twisting vibration preventive device in vehicular driving system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable suppression of twisting quaternary vibration of a driving system without remarkably varying a conventional clutch. SOLUTION: This device has a flywheel 5 arranged on an end of a crank shaft of an engine, a recession (shaft support hole 5a) formed on a center of the flywheel 5, viscous fluid S sealed in the recession, a rotational member 16 arranged in the viscous fluid S, and an input shaft (drive pinion 10) of a transmission to be fitted to the rotational member 16. In the twisting quaternary vibration where relative speed difference is generated between the flywheel 5 and the input shaft, large frictional force is generated between the surface of the rotational body 16 and the viscous fluid S. The relative speed difference between the flywheel 5 and the input shaft is reduced due to the frictional force. With such a setup, twisting of the flywheel and the input shaft is suppressed, and generation of twisting quaternary vibration is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing torsional vibration of a drive system of a vehicle which suppresses torsional quaternary vibration of the drive system.

[0002]

2. Description of the Related Art Generally, a drive system of a vehicle has a specific natural frequency, and when the engine speed is increased, torsional vibration is generated at a speed corresponding to the natural frequency. FIG. 3 shows a fourth-order torsional vibration of the drive system. In FIG. 3, white circles represent components of the drive system. The vertical axis represents the torsion angle, and the horizontal axis represents the power transmission direction of the component.

The above components are an engine flywheel, a transmission drive hub, a transmission main shaft, a final reduction gear reduction gear, and tires on the left side of the left end. The fourth torsional vibration is generated at the clutch flywheel. Is minus, and becomes plus at the drive pinion on the opposite side of the drive pinion and the clutch hub, so that torsional vibration occurs between the flywheel and the drive pinion.

That is, if the flywheel of the engine is relatively stopped, a large torsional vibration is generated at the connection with the drive pinion. This torsional vibration is often in a low rotation range in a normal car, and is often pointed out as a cause of cab vibration and booming noise.

[0005]

Conventionally, when such a fourth-order torsional vibration occurs, the resonance frequency is changed from the practical vehicle speed range, for example, from the low frequency side, by changing the inertia moment of the entire drive system and the spring constant of the clutch. The removal of the torsion vibration substantially eliminates the torsion vibration, and the drive system is not provided with a device for suppressing the torsional quaternary vibration.

An apparatus for suppressing the fourth-order torsional vibration is disclosed in Japanese Utility Model Publication No. Hei 4-30425 (JP-A-61-162).
No. 625) discloses a technique of reducing this torsional vibration by interposing a special dynamic damper between the clutch hub and the drive plate. Is necessary and cannot be applied to existing ones.

SUMMARY OF THE INVENTION The present invention has been devised in view of the above circumstances, and has as its object to provide a vehicle drive system capable of suppressing a torsional quaternary vibration of the drive system without requiring a major change to a conventional clutch. An object of the present invention is to provide a torsional vibration prevention device.

[0008]

According to the first aspect of the present invention, a flywheel provided at an end of a crankshaft 2 of an engine, a concave portion (bearing hole) formed at a center portion of the flywheel, A viscous fluid sealed in the concave portion, a rotating member (disc) disposed in the viscous fluid, and an input shaft (drive pinion) of a transmission fitted with the rotating member. It is characterized by.

In other words, with this configuration, when quaternary torsional vibration occurs in which a relative speed difference occurs between the flywheel and the input shaft, a large flow is generated between the surface of the rotating member and the viscous flow. Create a frictional force, which reduces the relative speed difference between the flywheel and the input shaft, and consequently reduces the relative speed difference between the flywheel and the input shaft, resulting in a twist between them. The fourth-order vibration is suppressed.

In this case, when the function of preventing the torsional quaternary vibration of the viscous fluid is set in the low rotation range of a normal vehicle, it is possible to greatly suppress the occurrence of cab vibration and muffled noise. Further, if a shaft support hole for supporting the drive pinion of the flywheel is directly used as a concave portion of the flywheel, the concave portion can be formed without any processing, and assembly and maintenance can be performed. This can also be done as before.

Further, since the effect of reducing the torsional quaternary vibration due to the frictional resistance with the viscous fluid is proportional to the surface area of the rotating body, it is possible to generate a frictional force capable of suppressing the torsional quaternary vibration, and If the rotation can be accommodated in the concave portion, the rotation is not limited to the disk, a rotating body of another shape,
For example, an arm-shaped member, a semi-disc, or a cup-shaped member extending radially outward from the outer periphery of the shaft may be used.

According to the second aspect of the present invention, if a casing having a substantially cup-shaped cross section is press-fitted into the recess and the viscous fluid is sealed in the casing, the sealing performance with the end face of the crankshaft is improved. And the reliability can be further improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 is a cross-sectional view showing the structure of the clutch 1. The clutch 1 is a flywheel that integrates the clutch disc 4 that transmits the power of an engine (not shown) to a transmission 3 and the clutch disc 4 that is integrated with the crankshaft 2. 5, a clutch pedal (not shown)
Is released, the pressure plate 6 presses the clutch disc 4 against the flywheel 5 by the spring force of the pressure spring 9 using the pin 8 of the eyebolt 7 as a fulcrum, and the clutch disc 4 pressed against the flywheel 5 It is configured to rotate with the wheel 5 and transmit power to a drive pinion 10 of the transmission 3.

When a clutch booster (not shown) is actuated by depressing a clutch pedal (not shown), the release fork 11 is actuated, and the release fork 11 pushes out the release bearing 12, and the release bearing 12 The pressure plate 6 connected to the clutch cover 14 is pulled back by the strap plate 13 connected to the outside. As a result, a gap is formed between the clutch disk 4 and the flywheel 5, and transmission of power to the transmission 3 is interrupted.

As shown in FIG. 1, in order to reduce the fourth-order torsional vibration of the drive system of the vehicle equipped with the clutch 1, the axial end of the flywheel 5, specifically, the input side end of the drive pinion 10, is provided. Boss 5a for supporting part 10a
The viscous fluid S, preferably silicone, is sealed in the shaft support hole 5b (recess) 5b of the drive pinion 10 while the shaft portion 15 extending into the shaft support hole 5b is formed in the input end 10a of the drive pinion 10.
Are attached integrally and coaxially, and a rotating member 16 for suppressing the twist generated between the drive pinion 10 and the flywheel 5 is attached to the shaft portion 15.

The rotating member 16 is constituted by a disk which rotates integrally with the shaft 15 together with the shaft 15, and when there is a relative speed difference between the drive pinion 10 and the flywheel 5. The relative speed difference is reduced by friction of the viscous fluid S made of silicone or the like.

In other words, by adopting such a structure, when a torsion occurs in which a relative speed difference occurs between the flywheel 5 and the drive pinion 10, if the torsion is allowed as it is, a torsional quaternary vibration occurs. There is a possibility that the booming sound of the cab may be deteriorated, but as such a configuration, a large frictional force acts on the surface of the rotating member 16 and the surface of the shaft portion 15, and the flywheel 5 and the drive pinion 10 Is eliminated, whereby torsional vibration between the flywheel 5 and the drive pinion 10 is suppressed. As a result, the flywheel 5 and the drive pinion 10 of the engine are substantially in a state of being rotated together with each other, and the vibration is greatly suppressed. Of course, when the engine speed becomes the engine speed at which the torsional quaternary vibration does not occur, there is no relative speed difference between the flywheel 5 and the drive pinion 10, and the wheels are in a rotating state in which they rotate together.

Therefore, the action of preventing the torsional vibration of the viscous fluid S is reduced to a low rotation range of a normal vehicle, for example, 500 to 800 rpm.
When it is set to m, the occurrence of cab vibration and muffled sound can be prevented, and the quietness of the cab can be drastically improved.

Here, the shaft support hole 5b of the flywheel 5
Is formed as a recess for sealing the viscous fluid S. One opening of the shaft support hole 5b is closed by the end face of the crankshaft 2, and the other opening of the shaft support hole 5b fits into the shaft support hole 5b. A sealed space closed by an input end 10a of the drive pinion 10 and a seal bearing 17 interposed between the input end 10a and the inner surface of the shaft support hole 5b is partitioned, and no processing is required. This is because the viscous fluid S can be sealed without the need to perform the operation.

In such a case, as shown in FIG. 1, a casing 18 having a substantially cup-shaped cross section is press-fitted into the recess 15 and the above-mentioned viscous fluid S such as silicone is sealed in the casing 18. Since the sealing performance with the end face of the shaft 2 can be further improved, the reliability can be dramatically improved.

The mounting structure of the shaft portion 15 to the drive pinion 10 is such that a spline fitting hole 10b is formed in the input end of the drive pinion 10, while the spline fitting hole 10b is formed in the shaft portion 15. A spline fitting shaft portion 15a to be fitted is formed, and the two are spline-coupled.
A screw hole (not shown) having a reverse screw opposite to the rotation direction of the crankshaft 2 is provided at the input end of the shaft 0, and a male screw portion (not shown) which is screwed into the screw hole and fastened to the shaft portion 15. They may be formed and then fastened together.

Here, in the present embodiment, a description has been given of the case where the rotating body that generates frictional force with the viscous fluid S is constituted by a disk, but the frictional resistance to the viscous fluid S is proportional to the surface area of the rotating body. Therefore, as long as a frictional force capable of suppressing the torsional quaternary vibration is generated and the size can be accommodated in the shaft support hole,
Another shape, for example, an arm-shaped member, a semi-disc, or a cup-shaped shape extending radially outward from the outer periphery of the shaft portion 15 may be used.

Although silicone is used as the viscous fluid S, the viscous fluid S mainly composed of silicone may be used as long as it has the same physical properties as silicone.
(For example, petroleum-based hydraulic oil) may of course be used.

[0024]

As is apparent from the above description, according to the first aspect of the present invention, when the torsional quaternary vibration occurs in which a relative speed difference occurs between the flywheel and the input shaft. A large frictional force can be generated between the rotating member surface and the viscous fluid, and the frictional force can reduce the relative speed difference between the rotary member and the flywheel input shaft. Thus, torsional vibration between the flywheel and the input shaft is suppressed. Therefore, if the torsional vibration preventing action by the viscous fluid is set in the low rotation range of a normal vehicle, the occurrence of cab vibration and muffled noise can be suppressed, and the quietness of the cab can be greatly improved. According to the second aspect of the invention, it is possible to improve the sealing performance with the end face of the crankshaft 2, so that the reliability can be dramatically improved.

[Brief description of the drawings]

FIG. 1 is a detailed sectional view of a main part of a clutch according to an embodiment of the present invention.

FIG. 2 is a sectional view of a clutch according to an embodiment of the present invention.

FIG. 3 is a vibration mode diagram showing a relationship between a component and a torsion angle when a fourth-order torsional vibration occurs in a drive system of a vehicle.

[Description of sign]

 Reference Signs List 2 crankshaft 3 transmission 5 flywheel 5a shaft support hole (recess) 10 drive pinion (input shaft) 16 rotating member S viscous fluid

Claims (2)

[Claims] 1. A flywheel disposed at an end of a crankshaft of an engine, a recess formed in a center portion of the flywheel, a viscous fluid sealed in the recess, and disposed in the viscous fluid. A torsional vibration preventing device for a drive system of a vehicle, comprising: a rotating member formed as described above; and an input shaft of a transmission fitted with the rotating member. 2. An apparatus for preventing torsional vibration of a drive system of a vehicle, wherein a substantially cup-shaped casing is press-fitted into the recess and the viscous fluid is sealed in the casing.