JPH02118228A - Flywheel device for engine - Google Patents

Abstract

PURPOSE:To avoid resonance and enable a favorable clutch disconnecting action by providing a thrust receiving portion which acts on a flywheel loosely fitted on a small diameter portion on the stepped face on the peripheral face or the front and of a small diameter portion steppedly provided on the rear end portion of a crankshaft. CONSTITUTION:A small diameter portion 2 is steppedly provided on the rear end portion of a crankshaft 1 and a flywheel 4 is loosely fitted on the outer peripheral face thereof by their respective taper splines 3, 5. Also, a plate member 7 having sufficiently low rigidity while having elasticity is fixed to the stepped face 6 of the small diameter portion 2 and the flywheel 4 with bolts 8, 9 while providing a slide restricting board 10 on the rear end portion of a small diameter portion 2 and a clutch device 13 in the rear of the flywheel 4. Hence, the resonance between the flywheel and engine can be avoided, reducing the noise in a vehicle while making a clutch disconnecting action favorable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine flywheel device, and more particularly to an improvement of a flywheel device in which a flywheel is attached to a crankshaft via a low-rigidity plate.

(Prior Art) Generally, in an engine, a flywheel is attached to one end of the crankshaft for the purpose of reducing rotational fluctuations of the crankshaft, but this flywheel generates so-called surface vibration when rotating, which resonates with engine vibration. When this occurs, large vibrations are transmitted to the vehicle body via the power plant mounting member, causing unpleasant interior noise.

Countermeasures against the problem of the flywheel surface runout vibration are known, for example, as disclosed in Japanese Utility Model Application Publication No. 58-151734. As shown in Fig. 5, an elastic low-rigidity plate B is attached to the rear end of the crankshaft A, and a flywheel C is connected to the outer periphery of this plate B. For example, the resonant frequency of the surface runout vibration of the flywheel C is
The frequency range of engine vibration that occurs in the normal operating range of the engine (for example, 600 to 600 in a 4-cylinder engine)
Rotational secondary 20-200H for 0RPM rotation range
z region) to the lower frequency side, and it can be expected that resonance between this surface runout vibration and engine vibration can be avoided.

(Problem to be Solved by the Invention) However, when the flywheel is attached to the crankshaft via a low-rigidity plate as described above, the clutch device supported by the flywheel does not connect or disconnect properly. This problem arises.

In other words, the clutch device that connects and disconnects the engine output is arranged between a clutch cup fixed to the flywheel, a pressure plate housed in the cover, and the flywheel and the pressure plate, and is connected to the input of the transmission. It consists of a clutch disc connected to the shaft and a disc spring that is supported by the clutch cover and urges the pressure plate in the clutch engagement direction, but when the clutch 7 is disconnected, the disc spring is pressed forward. Sometimes, the forward pressing force is transmitted to the flywheel via the clutch cover. At this time, if the flywheel is attached to the crankshaft via a low-rigidity plate, the plate will bend and the flywheel will escape forward, making it difficult for the clutch to disengage.

Therefore, the present invention aims to reduce the noise inside the car caused by the surface runout vibration of the flywheel by attaching the flywheel to the crankshaft via a low-rigidity plate as described above, and also aims to reduce the noise inside the car due to the vibration of the flywheel. An object of the present invention is to prevent the deterioration of the clutch, particularly the deterioration of the clutch disengagement due to flywheel escape when the clutch is disengaged.

(Means for Solving the Problems) In order to solve the above problems, the following means are used in the present invention.

That is, the flywheel device for an engine according to the present invention has a configuration in which the flywheel is attached to the rear end of the crankshaft via an elastic low-rigidity plate, and the rear end of the crankshaft has a small-diameter stepped structure. The flywheel is loosely fitted into the small diameter portion, and the forward thrust force acting on the flywheel is received by the circumferential surface of the small diameter portion or the stepped surface at the front end of the small diameter portion. A thrust receiver is provided.

(Function) According to the above configuration, the coupling rigidity of the flywheel to the crankshaft is reduced, so that the resonant frequency of the surface runout vibration of the flywheel shifts to a lower frequency side from the frequency range of engine vibration in the normal range. As it turned out,
In-vehicle noise caused by resonance between the flywheel surface vibration and engine vibration is reduced. and,
When a forward thrust force is applied to the flywheel through the clutch cover when the clutch device supported by the flywheel is disengaged, this thrust force is applied to the circumferential surface of the small diameter section at the rear end of the crankshaft or to the small diameter section. The flywheel is received by the thrust receiving part provided on the stepped surface at the front end, which prevents the flywheel from escaping forward due to the thrust force, thereby preventing the clutch from becoming more disengaged. .

(Example) Examples of the present invention will be described below.

First, the first embodiment of the present invention will be explained with reference to FIG. The portion 2 is provided in a stepped shape, and a tapered spline 3 is formed on the outer circumferential surface of the portion 2, and a tapered spline 5 similarly provided on the inner circumferential surface of the flywheel 4 provides a required clearance to the tapered spline 3. It is loosely fitted.

Further, an inner peripheral portion of a plate member 7 having elasticity and sufficiently low rigidity is fixed to the stepped surface 6 at the front end of the small diameter portion 2 by a plurality of bolts 8...8. The outer periphery of this plate member 7 and the flywheel 4
are connected to the outer circumference of the flywheel 4 by a plurality of bolts 9 . It has a structure in which it is attached to the crankshaft 1 via a plate member 7 in a state in which Here, a slide regulating plate 10 is fixed to the rear end of the small diameter portion 2 by bolts 11 to prevent the spline-fitted flywheel 4 from coming off backward. A bolt 8 for fastening the plate member 7 to the crankshaft 1 is provided on the inner circumference of the flywheel 4.
A plurality of through holes 4a...4a for inserting the...8 are provided.

Further, a ring gear 12 is provided on the outer peripheral surface of the flywheel 4 for driving the flywheel 4 or the crankshaft 1 by a starter motor.

On the other hand, a clutch device 13 is provided behind the flywheel 4. This clutch device 13 includes a clutch cover 15 fixed to the rear surface of the outer circumferential portion of the flywheel 4 by a plurality of bolts 14...14, and is housed within the cover 15 and is movable back and forth on a transmission input shaft 16. A spline-fitted clutch disc 17, a pressure plate 18 supported so as to be movable back and forth on the clutch cover 15 so as to face the rear surface of the flywheel 4 with the clutch disc 17 in between, and the clutch cover 15 as well.
The pressure plate 18 is supported by a disc spring 19 whose outer peripheral portion is in contact with the rear surface of the pressure plate 18 . Normally, the disc spring 19 biases the pressure plate 18 forward, so that the pressure plate 18
A quick latch disc 17 is sandwiched between the flywheel 4 and the crankshaft 1 and the transmission input shaft 16 are connected via the disc 17, but when the clutch pedal is depressed, the release bearing (not shown) presses the inner periphery of the disc spring 19 forward, causing the outer periphery of the disc spring 19 to separate from the pressure plate 18 and press against the clutch disc 17 between the flywheel 4 and the flywheel 4. The pinching state is released, and as a result,
The crankshaft 1 and the transmission input shaft 16 are disconnected.

Next, to explain the operation of this embodiment, as shown in FIG.
is sandwiched between the flywheel 4 and the pressure plate 18, and when the crankshaft 1 and the transmission input shaft 16 are connected, the taper spline 5 provided on the inner peripheral surface of the flywheel 4 and the , a tapered spline 3 provided on the outer peripheral surface of the small diameter portion 2 at the rear end of the crankshaft.
and are loosely fitted to each other with a required clearance. Therefore, in this state, the flywheel 4 is supported by the crankshaft 1 only through the plate member 7, and its support rigidity is sufficiently low, and this also causes the surface of the flywheel 4 to be low. The resonance frequency of the runout vibration is also sufficiently low, and is shifted to a lower frequency side than the engine vibration frequency range in the normal use range.

This prevents the surface runout vibration of the flywheel 4 from resonating with engine vibration, and reduces the unpleasant interior noise caused by this resonance vibration being transmitted to the vehicle body via the mounting member of the power plant. Become.

On the other hand, when the clutch pedal is depressed to disconnect the clutch device 13, a release bearing (not shown) presses the inner circumferential portion of the disc spring 19 forward, and the clamping state of the clutch disc 17 due to the biasing force of the disc spring 19 is suppressed. At this time, the forward pressing force from the release bearing is transmitted from the disc spring 19 to the flywheel 4 via the clutch cover 15. Therefore, the flywheel 4 tries to move forward by deforming the plate member 7, but the flywheel 4 has a tapered spline 5 provided on the inner circumferential surface of the flywheel 4, which is connected to the tapered spline 5 of the small diameter section 2 at the rear end of the crankshaft. 3, the two taper splines 3.5 are completely engaged when the splines 3.5 are displaced slightly forward, as shown by the chain line in Figure 3, and further forward displacement is prevented. It is. As a result, the flywheel 4 is completely fixed to the crankshaft 1, and the forward pressing force transmitted from the release bearing via the disc spring 19 and the clutch cover 15 is applied to the flywheel 4. This means that the clutch device 13 can be reliably received and the disconnection operation of the clutch device 13 can be performed satisfactorily.

In addition, in this embodiment, torque can be transmitted from the crankshaft 1 to the flywheel 4 via the fitting portion of both the tapered splines 3.5.
The load (shearing force) acting on the bolts 8...8, 9...9 that connect the plate member 7, crankshaft 1, and flywheel 4, respectively, is reduced, and the durability of these joints is improved. At the same time, the rigidity of the plate member 7 can be sufficiently reduced, and the above-mentioned resonance can be avoided more effectively.

Next, a second embodiment of the present invention shown in FIG. 4 will be described.

In this embodiment, a small diameter portion 22 having a cylindrical outer peripheral surface is provided in a stepped manner at the rear end of the crankshaft 21, and a ring member 23 made of an oil-impregnated alloy is fitted and fixed to the outer peripheral surface of the small diameter portion 22. At the same time, the inner circumferential surface of a flywheel 24 is slidably and loosely fitted to the outside of the ring member 23.

Further, in this embodiment, a flange portion 25 is provided in front of the small diameter portion 22 of the crankshaft 21, and the flange portion 25 is provided with elasticity and sufficiently low rigidity by a plurality of bolts 26...26. plate member 27
The inner periphery of the plate member 27 is coupled to the plate member 27.
The outer periphery of the flywheel 24 and the outer periphery of the flywheel 24 are connected by a plurality of bolts 28...28.

Furthermore, a flywheel 24 is attached to the rear end of the small diameter portion 22 of the crankshaft 21 by bolts 29...29.
A slide regulating plate 30 is fixed to the flywheel 4 to prevent it from coming off backward, and the front surface of the inner circumference of the flywheel 4,
Elastic members 3 are provided between the stepped surface 31 at the front end of the small diameter portion 22 of the crankshaft 21 and between the rear surface of the inner peripheral portion of the flywheel 24 and the slide regulating plate 30, respectively.
2.33 is interposed.

Here, the fitting portion between the inner circumferential surface of the flywheel 24 and the ring member 23 is allowed to have a very small inclination due to surface runout of the flywheel 24, but when the clutch device 34 is engaged, the flywheel 24 A clearance is provided to the extent that the flywheel 24 is prevented from relatively large inclination when a compensating pressing force is applied.

In this embodiment as well, although the flywheel 24 is normally coupled to the crankshaft 21 via the plate member 27 with low rigidity, the resonance frequency of the surface runout vibration of the flywheel 24 is low and the engine vibration resonance is avoided, and the noise inside the vehicle due to this resonance is reduced.

When the clutch device 34 is disconnected and a forward pressing force acts on the flywheel 24 from the disc spring 35 through the clutch cover 36, the flywheel 24
4 slides slightly forward on the ring member 23 and comes into contact with the stepped surface 31 of the crankshaft 21 via the elastic member 32, and is prevented from sliding forward at that position.

Therefore, in this embodiment as well, although the flywheel 24 is coupled to the crankshaft 21 via the low-rigidity plate member 27, the forward pressing force when the clutch device 34 is disengaged is applied to the flywheel. The clutch device 3 is securely received by the wheel 24.
The cutting operation in step 4 will be performed satisfactorily.

(Effects of the Invention) As described above, according to the flywheel device according to the present invention, since the flywheel is attached to the crankshaft via the low-rigidity plate, the resonance between the surface runout vibration of the flywheel and the engine vibration is reduced. As a result, unpleasant in-vehicle noise caused by this resonant vibration being transmitted to the vehicle body is reduced.

When the clutch device supported by the flywheel is disengaged, the forward thrust force acting on the flywheel is reliably received and the flywheel is fixed, so that the clutch disengagement operation can be performed satisfactorily. You will be killed.

[Brief explanation of the drawing]

1 to 4 show embodiments of the present invention; FIG. 1 is a longitudinal cross-sectional side view of a flywheel device according to the first embodiment;
The figures are a longitudinal sectional front view of the main part taken along the line ■-■ in Fig. 1, Fig. 3 is an enlarged longitudinal sectional side view of the main part showing the operation of the embodiment, and Fig. 4 is a longitudinal sectional side view of the second embodiment. . Moreover, FIG. 5 is a schematic sectional view showing a conventional flywheel device. 1.21...Crankshaft, 2.22...Small diameter part, 4
．． 24... Flywheel, 7.27... Low rigidity plate (plate member), 3.31... Thrust receiver (tapered spline, stepped surface). Figure 1

Claims (1)

[Claims] (1) An engine flywheel device in which a flywheel is attached to the rear end of the crankshaft via an elastic low-rigidity plate, wherein the rear end of the crankshaft is provided with a small diameter part in a stepped shape, The flywheel is loosely fitted into the small diameter portion, and a thrust receiving portion is provided on the circumferential surface of the small diameter portion or a stepped surface at the front end of the small diameter portion to receive the forward thrust force acting on the flywheel. An engine flywheel device characterized by: