JP2019143663A - Dual mass flywheel - Google Patents

Abstract

To provide a dual mass flywheel capable of suitably suppressing noise due to surface wobbling resonance of a primary wheel.SOLUTION: A frequency at which a value (FMAX) obtained by performing +1st order conversion with respect to an engine speed to the maximum engine speed NMAX is smaller than a resonance frequency FP of a power plant mounted on a vehicle, is set as a surface wobbling resonance frequency F1 at the time of stopping rotation of a primary wheel, and a frequency equal to the surface wobbling resonance frequency at the time of stopping the rotation of the primary wheel is set as a surface wobbling resonance frequency F2 at the time of stopping rotation of a secondary wheel.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a dual mass flywheel.

  As a flywheel connected to the crankshaft of an engine, a dual mass flywheel composed of two wheels connected via an elastic body such as a torsional damper is known as disclosed in Patent Document 1. . In the dual mass flywheel described in this document, a dynamic damper is installed on the secondary wheel. And thereby, the resonance frequency of the rotational shake of the secondary wheel is changed to adjust the resonance frequency of the rotational shake of the entire dual mass flywheel, thereby suppressing the resonance of the dual mass flywheel due to engine vibration.

JP 2009-115184 A

  A power plant, which is a connected body of an engine and a transmission in a vehicle, is mounted on the vehicle while being elastically supported by the vehicle body by mounting. It is known that when the resonance frequency of such a power plant overlaps with the surface vibration resonance frequency of the primary wheel of the dual mass flywheel, a noise called a goro-ro sound is generated. However, in the past, the actual situation is that no appropriate measures have been taken with respect to the noise caused by the surface vibration of the primary wheel.

  The present invention has been made in view of such circumstances, and a problem to be solved is to provide a dual mass flywheel capable of suitably suppressing noise due to surface vibration of the primary wheel.

  A dual mass flywheel that solves the above problem is interposed between an engine and a transmission in a power plant of a vehicle that is a connection body of the engine and the transmission, and is connected to a crankshaft of the engine. A primary wheel, and a secondary wheel coupled to the primary wheel via an elastic body.

  While the engine is running, the primary wheel of the dual mass flywheel will run out while rotating. When viewed from a non-rotating power plant, the surface runout resonance frequency of the rotating primary wheel is considered to cause ± first order conversion with respect to the rotation speed of the primary wheel (= engine speed). Therefore, the maximum value of the surface vibration resonance frequency of the primary wheel during engine operation as seen from the power plant is a value obtained by performing + first order conversion on the engine speed with respect to the maximum engine speed.

  On the other hand, in the dual mass flywheel, the frequency at which the maximum value is smaller than the resonance frequency of the power plant mounted on the vehicle is set as the surface vibration resonance frequency when the primary wheel stops rotating. ing. If it does in this way, it can avoid that the surface vibration resonant frequency of a primary wheel overlaps with the resonant frequency of a power plant, and noise generate | occur | produces during engine operation.

  On the other hand, if the surface vibration frequency of the primary wheel overlaps with the frequency of the low-order component of the engine vibration in the normal range of engine speed, the surface vibration of the primary wheel will occur frequently and the durability of the primary wheel May be damaged. In order to avoid the occurrence of surface runout resonance of the primary wheel due to such engine vibration, it is necessary to set a higher frequency than a certain level as the surface runout resonance frequency of the primary wheel. In such a case, a low frequency that can avoid the overlap with the resonance frequency of the power plant during engine operation as described above may not be set as the surface vibration resonance frequency of the primary wheel.

  On the other hand, in the dual mass flywheel, a frequency equal to the surface vibration resonance frequency when the rotation of the primary wheel is stopped is set as the surface vibration resonance frequency when the rotation of the secondary wheel is stopped. In such a case, when the primary wheel surface vibration resonance occurs, the secondary wheel functions as a dynamic damper that absorbs the surface vibration resonance. Therefore, the surface vibration of the primary wheel due to engine vibration can be allowed to some extent. Therefore, it becomes easy to set a low frequency overlapping with the frequency of engine vibration as the surface vibration resonance frequency when the primary wheel stops rotating. Therefore, according to the dual mass flywheel, noise due to surface vibration of the primary wheel can be suitably suppressed.

The schematic diagram of the power plant of the vehicle with which one Embodiment of a dual mass flywheel is applied. Sectional drawing of the dual mass flywheel. Model diagram of the dual mass flywheel. The graph which shows the setting aspect of the surface vibration resonance frequency of the primary wheel in the dual mass flywheel.

Hereinafter, an embodiment of a dual mass flywheel will be described in detail with reference to FIGS.
As shown in FIG. 1, the dual mass flywheel 10 of this embodiment is provided in a portion between an engine 11 and a transmission 12 in a power plant 13 of a vehicle that is a connected body of an engine 11 and a transmission 12. Is done. The power plant 13 is mounted on the vehicle while being elastically supported by the vehicle body 15 via the mounting 14. The dual mass flywheel 10 is connected to the output end of the crankshaft 16 of the engine 11 and is connected to the transmission input shaft 18 via the clutch 17 and provided in the power plant 13. ing.

  As shown in FIG. 2, the dual mass flywheel 10 includes a primary wheel 19 connected to the crankshaft 16 so as to be integrally rotatable, and a secondary wheel connected to the primary wheel 19 via a torsional damper 20 that is an elastic body. 21. The secondary wheel 21 is installed on the dual mass flywheel 10 in a state of being pivotally supported by the primary wheel 19 so as to be relatively rotatable by a bearing 22. Further, in the dual mass flywheel 10, the torsional damper 20 is installed so as to generate an elastic repulsive force against the relative rotation of the primary wheel 19 and the secondary wheel 21. The secondary wheel 21 is connected to the transmission input shaft 18 via the clutch 17.

  As shown in FIG. 3, pressure is applied to the crankshaft 16 during engine operation from a piston P that descends in response to combustion. When the crankshaft 16 is shaken by the pressing, the surface shake of the primary wheel 19 connected to the crankshaft 16 is generated. In the following description, the surface vibration resonance frequency when the rotation of the primary wheel 19 in the state where the dual mass flywheel 10 is assembled to the power plant 13 is “F1”, and the rotation of the secondary wheel 21 in the same state is stopped. Let the surface vibration resonance frequency of F be “F2”.

  On the other hand, when the resonance of the power plant 13 installed in a state elastically supported by the vehicle body 15 via the mounting 14 and the surface vibration of the primary wheel 19 occur simultaneously as described above, a noise called a roaring sound is generated. Occur. While the engine is running, the primary wheel 19 causes surface vibration while rotating. When viewed from a power plant 13 that is not rotating (in the stationary coordinate system), the surface vibration resonance frequency F1 of the primary wheel 19 that is rotating (in the rotating coordinate system) is the rotational speed of the primary wheel 19 (= engine It is considered that ± 1st order changes with respect to the number of revolutions) occur. That is, the surface runout resonance frequency F1 * of the primary wheel 19 during rotation when viewed from the power plant 13 is expressed by the following formula for the engine run speed NE and the surface runout resonance frequency [Hz] when the primary wheel 19 stops rotating: The value satisfies the relationship 1).

As shown in FIG. 4, the minimum value FMIN in the range of values that can be taken by the surface vibration resonance frequency F1 * during engine operation is the −1st order conversion for the maximum engine speed NMAX of the engine 11 to the surface vibration resonance frequency F1. The applied value (FMIN = F1-NMAX / 60). Further, the maximum value FMAX in the range of values that can be taken by the surface vibration resonance frequency F1 * during engine operation is a value obtained by subjecting the surface vibration resonance frequency F1 to + 1st order conversion with respect to the maximum rotation speed NMAX (FMAX = F1 + NMAX). / 60). Therefore, the frequency at which the minimum value FMIN is greater than the resonance frequency FP, or the frequency at which the maximum value FMAX is smaller than the resonance frequency FP is defined as the surface vibration resonance frequency F1 when the primary wheel 19 stops rotating. If set, generation of noise due to surface vibration resonance can be suppressed.

  The primary wheel 19 that functions as an inertial body for suppressing the rotational fluctuation of the crankshaft 16 needs to have a certain mass or more. Further, there is a limit to improving the rigidity of the primary wheel 19. Therefore, it is difficult to set a high frequency at which the minimum value FMIN is larger than the resonance frequency FP as the surface vibration resonance frequency F1, and the maximum value FMAX is lower than the resonance frequency FP. It is easier to set the frequency as the surface vibration resonance frequency F1.

  Therefore, when a low frequency at which the maximum value FMAX is smaller than the resonance frequency FP is set as the surface vibration resonance frequency F1, the surface vibration resonance frequency F1 of the primary wheel 19 is a low-order component of engine vibration during engine operation ( There is a risk of a low frequency overlapping the primary component and the secondary component. For example, in FIG. 4, when the engine speed NE is “N1”, the frequency of the secondary component of the engine vibration becomes the same frequency as the surface vibration resonance frequency F1, and the primary wheel 19 causes surface vibration resonance. When this “N1” is a value within the normal range of the engine speed, there is a possibility that surface vibration resonance occurs at a high frequency and the durability of the primary wheel 19 is impaired.

  On the other hand, in the dual mass flywheel 10 of this embodiment, a frequency equal to the surface vibration resonance frequency F1 when the rotation of the primary wheel 19 is stopped is set as the surface vibration resonance frequency F2 when the rotation of the secondary wheel 21 is stopped. ing. The surface vibration resonance frequency F <b> 2 of the secondary wheel 21 can be adjusted by changing the mass of the secondary wheel 21 or changing the rigidity of the bearing 22 that pivotally supports the secondary wheel 21.

  In this way, the secondary wheel 21 set with the surface vibration resonance frequency F <b> 2 functions as a dynamic damper that absorbs vibration of the primary wheel 19 when surface vibration resonance occurs in the primary wheel 19. For this reason, the surface vibration resonance of the primary wheel 19 due to engine vibration can be allowed to some extent. As a result, a low frequency at which the maximum value FMAX is smaller than the resonance frequency FP of the power plant 13 can be easily set as the surface vibration resonance frequency F1 of the primary wheel 19. Therefore, according to the dual mass flywheel 10 of the present embodiment, it is possible to suitably suppress noise due to surface vibration of the primary wheel.

This embodiment can be implemented with the following modifications. The present embodiment and the following modifications can be implemented in combination with each other within a technically consistent range.
In the dual mass flywheel 10, an elastic body other than the torsional damper 20 such as a coil spring may be used as an elastic body that connects the primary wheel 19 and the secondary wheel 21.

  In the dual mass flywheel 10 of the above embodiment, the secondary wheel 21 is connected to the transmission input shaft 18 via the clutch 17. The dual mass flywheel 10 of the above embodiment can be similarly applied to a power plant provided with a torque converter or the like instead of the clutch 17.

  DESCRIPTION OF SYMBOLS 10 ... Dual mass flywheel, 11 ... Engine, 12 ... Transmission, 13 ... Power plant, 14 ... Mounting, 15 ... Car body, 16 ... Crankshaft, 17 ... Clutch, 18 ... Transmission input shaft, 19 ... Primary wheel, DESCRIPTION OF SYMBOLS 20 ... Torsional damper (elastic body), 21 ... Secondary wheel, 22 ... Bearing, F1 ... Surface vibration resonance frequency when rotation of primary wheel stops, F2 ... Surface vibration resonance frequency when rotation of secondary wheel stops, FP ... Vehicle Resonant frequency of the power plant mounted on the.

Claims (1)

A primary wheel that is interposed between the engine and the transmission in a power plant of a vehicle that is a connected body of the engine and the transmission, and that is connected to a crankshaft of the engine, and elastic to the primary wheel In a dual mass flywheel comprising a secondary wheel connected through the body,
The frequency at which the value obtained by performing the + 1st order conversion on the engine speed with respect to the maximum engine speed is smaller than the resonance frequency of the power plant mounted on the vehicle is the rotation of the primary wheel. It is set as the surface runout resonance frequency when stopped,
In addition, a dual mass flywheel in which a frequency equal to a surface vibration resonance frequency when the rotation of the primary wheel is stopped is set as a surface vibration resonance frequency when the rotation of the secondary wheel is stopped.