JP2009115184A - Dual mass flywheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce resonance of a dual mass flywheel in an engine starting rotational area of an idle speed or less. <P>SOLUTION: This dual mass flywheel 1 has a primary flywheel 11 connected to a crankshaft 100 and a secondary flywheel 12 on the clutch side, and is formed by connecting these primary flywheel 11 and secondary flywheel 12 via a torsion spring (an elastic body) 13. A dynamic damper 2 is arranged in the secondary flywheel 12. Mass of a mass member 21 of its dynamic damper 2 and a spring constant of the elastic body 22 are adjusted, and the resonance of the dual mass flywheel 1 in the engine starting rotational area is reduced by tuning a resonance frequency of the dynamic damper 2 to a resonance frequency of the dual mass flywheel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a flywheel connected to a crankshaft of an engine (internal combustion engine), and more particularly to a dual mass flywheel that absorbs and reduces fluctuations in engine output torque.

  In a vehicle equipped with an engine, a flywheel is connected to the crankshaft of the engine for the purpose of preventing unstable fluctuations in rotational speed during engine start-up and idle operation and engine stoppage caused by it. The engine output is transmitted to external elements (such as a clutch and a transmission) via the flywheel.

  Further, the drive torque transmitted to the power transmission system in a vehicle equipped with the engine has a variation caused by the explosion of the engine, and the torque variation causes torsional vibration in the power transmission system. There is a dual mass flywheel as a means for preventing such torsional vibration of the drive system (for example, see Patent Document 1).

  As the dual mass flywheel, for example, a primary flywheel (first mass) connected to the crankshaft of the engine and a secondary flywheel (second mass) arranged on the clutch side (transmission side) are provided. There is a structure in which the primary flywheel and the secondary flywheel are connected via an elastic body (damper) such as a torsion spring. According to the dual mass flywheel having this structure, torque fluctuation generated on the engine side can be absorbed and reduced by the damper, so that transmission of torque fluctuation to the external element can be suppressed, and vibration noise can be reduced.

In addition, there are technologies described in Patent Documents 2 and 3 below for reducing vibrations of a crankshaft in a vehicle equipped with an engine. In the techniques described in Patent Documents 2 and 3, bending vibration and the like are suppressed by providing a dynamic damper on a flywheel body or a clutch disk cover attached to the flywheel in a single mass flywheel.
Japanese Utility Model Publication No. 4-39451 Japanese Utility Model Publication No. 2-53550 Japanese Utility Model Publication No. 62-112348

  By the way, since the dual mass flywheel is comprised by two masses and an elastic member (spring), it has a resonance point (natural frequency). If the resonance point exists in a rotation speed region (normal rotation region) in which the engine is normally used, the crankshaft and the flywheel resonate during normal use of the engine, and large vibrations are generated. For this reason, the resonance point of the dual mass flywheel is set in a region equal to or lower than the idle speed (for example, around 300 to 400 rpm).

  Thus, if the resonance point of the dual mass flywheel is in the region below the idle rotation speed (engine start rotation region), it will always pass through the resonance point (resonance rotation speed) when the engine is started. A resonance phenomenon occurs every time the engine is started, and the durability of the dual mass flywheel is lowered. Moreover, it becomes a factor which generate | occur | produces abnormal noise at the time of low rotation below an idle rotation speed.

  In order to solve this problem, a measure is taken to increase the rigidity of components (for example, a torsion spring and a member that supports the torsion spring) constituting the dual mass flywheel. However, with such a measure, it is necessary to increase the rigidity of the flywheel components in order to only achieve the objective of reducing resonance in the engine starting rotation region.

  As another countermeasure, the hysteresis (friction resistance) between the primary flywheel and the secondary flywheel is also increased. However, in this countermeasure, the original effect of the dual mass flywheel, that is, the torsional vibration is reduced. Absorption / reduction effect may be reduced.

  Note that Patent Document 1 only shows the basic structure of a dual mass flywheel, and does not suggest the above-described problem of the resonance point. Moreover, the techniques described in Patent Documents 2 and 3 are intended for a single mass flywheel and do not have the problems (resonance phenomenon) inherent to the dual mass flywheel described above. Therefore, even if the techniques described in Patent Documents 2 and 3 are used, the above-described problem of the resonance point cannot be solved. In addition, although patent document 2 has description about a dual mass flywheel, similarly to patent document 1, only the basic structure of a dual mass flywheel is shown. Is not suggested at all.

  The present invention has been made in view of such circumstances, and provides a dual mass flywheel having a structure capable of reducing resonance in the engine starting rotation region and ensuring durability. Objective.

  In order to achieve the above object, the present invention comprises a primary flywheel coupled to an engine crankshaft and a secondary flywheel, wherein the primary flywheel and the secondary flywheel are coupled via an elastic body. In the dual mass flywheel, the secondary flywheel is provided with a dynamic damper including a mass member and an elastic body.

  According to the present invention, since the dynamic damper is provided in the secondary flywheel on the clutch side (transmission side), the resonance of the dual mass flywheel in the engine start rotation region can be reduced.

  Specifically, the resonance frequency [resonance frequency f = (1 / 2π) √ (K / M)] of the dynamic damper provided in the secondary flywheel is set to the mass (M) of the mass member and the spring constant (K ) To adjust the resonance frequency of the dual mass flywheel (for example, the frequency corresponding to the engine speed of 300 to 400 rpm), the resonance of the dynamic mass damper can cancel the resonance of the dual mass flywheel. The resonance of the dual mass flywheel in the starting rotation region can be reduced. This eliminates the need to take measures to increase the rigidity of flywheel components, such as torsion springs, only to reduce resonance in the engine start rotation region.

  In the present invention, a plurality of dynamic dampers having different characteristics may be provided in parallel to the secondary flywheel. If such a configuration is adopted, the frequency region of the dynamic damper effect can be expanded.

  For example, a dynamic damper composed of a mass member having a mass M21 and an elastic body having a spring constant K21 and a dynamic damper composed of a mass member having a mass M22 and an elastic body having a spring constant K22 are arranged in parallel to the outer periphery of the secondary flywheel (FIG. 4). If the relationship between the mass of the two dynamic dampers and the spring constant is M21> M22 and K21 <K22, the mass of the mass member is large and the elastic damper has a low spring constant. Thus, the low frequency component in the engine start rotation region can be reduced, and the high frequency component in the engine start rotation region is reduced by the dynamic damper on the side where the mass of the mass member is small and the spring constant of the elastic body is high. Therefore, the frequency range of the dynamic damper effect can be expanded.

  Further, in the present invention, even if elastic bodies and mass members are arranged alternately and in series on the secondary flywheel, a plurality of dynamic dampers having different characteristics by the plurality of mass members and the plurality of elastic bodies may be configured. Good. Also in this case, the frequency region of the dynamic damper effect can be expanded.

  For example, two mass members and two elastic bodies are used, and the plurality of mass members and elastic bodies are arranged in series in the order of [elastic body → mass member → elastic body → mass member] on the outer periphery of the secondary flywheel. When connected to each other, a high-frequency component in the engine start rotation region can be reduced by a dynamic damper composed of a mass member (single mass member) far from the secondary flywheel and an elastic body. Moreover, it is close to the secondary flywheel with the composite mass member (mass of composite mass member> mass of the above-mentioned single mass member) composed of the mass member far from the secondary flywheel, the elastic body, and the mass member on the near side. The low frequency component in the engine start rotation region can be reduced by the dynamic damper composed of the elastic body on the side. Therefore, also in this case, the frequency region of the dynamic damper effect can be expanded.

  According to the present invention, in the dual mass flywheel in which the primary flywheel and the secondary flywheel attached to the crankshaft are connected via the elastic body, the secondary flywheel on the clutch side includes the mass member and the elastic body. Therefore, by adjusting the resonance frequency of the dynamic damper, it is possible to reduce the resonance of the dual mass flywheel in the engine starting rotation region. Thus, durability can be ensured without increasing the rigidity of components such as the torsion springs constituting the dual mass flywheel.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a front view of a dual mass flywheel to which the present invention is applied. 2 is a cross-sectional view taken along the line XX of FIG.

  The dual mass flywheel 1 of this example is mainly composed of an engine-side primary flywheel 11, a clutch-side secondary flywheel 12, a torsion spring (compression coil spring) 13, a hub 14, and a flange 15. .

  A hub 14 is fixed to the primary flywheel 11 with rivets 5a. The primary flywheel 11 and the hub 14 are connected to the crankshaft 100 of the engine and rotate together with the crankshaft 100.

  A ring gear 16 is provided on the outer peripheral portion of the primary flywheel 11. A starter motor or the like is meshed with the ring gear 16 when the engine is started, and the crankshaft 100 is rotated by the power of the starter motor or the like. Further, a cover 18 covering the inertia ring 17 and the torsion spring 13 is fixed to the primary flywheel 11 by welding or the like.

  The secondary flywheel 12 is rotatably supported by the hub 14 via a ball bearing 19. A flange 15 is fixed to the secondary flywheel 12 by a rivet 5b, and the secondary flywheel 12 and the flange 15 rotate integrally.

  The flange 15 is a disk-shaped member disposed between the primary flywheel 11 and the secondary flywheel 12. A plurality of window holes 15 a extending in the circumferential direction are opened in the flange 15. A torsion spring 13 is disposed in each window hole 15 a of the flange 15, and the primary flywheel 11 and the secondary flywheel 12 are connected to each other in the rotational direction via the torsion spring 13 and the flange 15.

  The secondary flywheel 12 is formed with a clutch friction surface 12a, and a clutch disk 302 is disposed opposite to the clutch friction surface 12a. A clutch cover assembly 300, a release bearing 401, a release fork 402, and the like are disposed on the transmission side of the secondary flywheel 12.

  The clutch cover assembly 300 includes a clutch cover 301 fixed to the secondary flywheel 12, a pressure plate 303 that presses the clutch disk 302, a diaphragm spring 304, and the like. The pressure plate 303, the diaphragm spring 304, and the like are included in the clutch cover 301. It is assembled to.

  The secondary flywheel 12, the clutch disc 302, the clutch cover assembly 300, and the like constitute a clutch. In the clutch having such a configuration, the pressure plate 303 is pressed toward the dual mass flywheel 1 by the elastic force of the diaphragm spring 304, and the clutch disk 302 is moved to the secondary flywheel by the elastic force of the diaphragm spring 304. The clutch friction surface 12a of the wheel 12 is pressed against and the clutch is engaged.

  On the other hand, when the release bearing 401 is moved toward the secondary flywheel 12 by the release fork 402 and a hydraulic actuator (not shown), the elastic force of the diaphragm spring 304 is moved away from the secondary flywheel 12. As a result, the clutch disc 302 is separated from the clutch friction surface 12a of the secondary flywheel 12 to be in a clutch released state.

  In this example, the dynamic damper 2 is provided on the outer periphery of the secondary flywheel 12 of the dual mass flywheel 1 having the above structure.

  The dynamic damper 2 is arranged between a ring-shaped mass member 21 having a larger diameter than the secondary flywheel 12 and an inner peripheral surface of the ring-shaped mass member 21 and an outer peripheral surface of the secondary flywheel 12. It is constituted by two elastic bodies 22. The ring-shaped mass member 21 is arranged concentrically with respect to the secondary flywheel 12. The four elastic bodies 22 are arranged rotationally symmetrical in the circumferential direction, and the mass member 21 is connected to the secondary flywheel 12 via the four elastic bodies 22.

  Next, the operation of the dual mass flywheel 1 of this example will be described.

  First, torque generated by the engine is input to the dual mass flywheel 1 via the crankshaft 100. Torque input to the dual mass flywheel 1 is transmitted to the secondary flywheel 12 via the primary flywheel 11, the torsion spring 13 and the flange 15.

  When such torque is transmitted, when a torsional vibration component is input from the crankshaft 100 to the primary flywheel 11 of the dynamic damper 2, the primary flywheel 11 and the secondary flywheel 12 (flange 15) rotate relative to each other, and the relative rotation occurs. Accordingly, the torsion spring 13 expands and contracts between the primary flywheel 11 and the flange 15. Torsional vibration is absorbed and damped by the elastic action of the torsion spring 13.

  By the way, since the dual mass flywheel 1 is composed of two masses and an elastic body (spring) as described above, it has a resonance point (resonance rotation speed), and the resonance point is a region below the idle rotation speed. (For example, around 300 to 400 rpm). Thus, if the resonance point of the dual mass flywheel 1 exists in the region below the idle speed (engine start region), the engine always starts when the engine is started. Each time the resonance phenomenon occurs, there is a problem that the durability of the flywheel components such as the torsion spring 13 and the flange 15 constituting the dual mass flywheel 1 is lowered.

  Therefore, in this example, by providing the dynamic damper 2 composed of the mass member 21 and the elastic body 22 on the outer periphery of the secondary flywheel 12, the resonance of the dual mass flywheel 1 in the engine start rotation region is reduced.

  More specifically, if the mass of the mass member 21 of the dynamic damper 2 is M1, and the total spring constant of the four elastic bodies 22 is K1, the resonance frequency f1 of the dynamic damper 2 is f1 = (1 / 2π) √ It can be expressed as (K1 / M1). Using this relational expression, the resonance frequency f1 of the dynamic damper 2 is adjusted by adjusting the mass M1 of the mass member 21 and the overall spring constant K1 of the four elastic bodies 22, so that the resonance frequency of the dual mass flywheel 1 (for example, engine rotation) By tuning to a frequency corresponding to several 300 to 400 rpm, it becomes possible to cancel the resonance of the dual mass flywheel 1 by the resonance of the dynamic damper 2. For example, as shown in the graph of FIG. The resonance of the dual mass flywheel 1 can be effectively reduced.

  Thereby, the durability of the dual mass flywheel 1 can be ensured without increasing the rigidity of components such as the torsion spring 13 and the flange 15 constituting the dual mass flywheel 1 more than necessary.

  In the example shown in FIGS. 1 and 2, the elastic bodies 22 are provided at four locations on the outer periphery of the secondary flywheel 12, but the number of installation locations of the elastic bodies is arbitrary, for example, three locations. Good. Further, an elastic body may be provided over the entire circumference of the secondary flywheel 12 as long as the resonance frequency f1 of the dynamic damper 2 can be matched with the resonance frequency of the dual mass flywheel 1.

-Other examples of dynamic dampers-
Another example of the dynamic damper provided in the secondary flywheel 12 will be described with reference to FIG.

  In this example, a dynamic damper 201 including a mass member 211 having a mass M21 and an elastic body 212 having a spring constant K21, and a dynamic damper 202 including a mass member 221 having a mass M22 and an elastic body 222 having a spring constant K22 are connected to a secondary fly. It is characterized in that it is provided in parallel on the outer periphery of the wheel 12.

  In these two dynamic dampers 201 and 202, the mass M21 of the mass member 211 of one dynamic damper 201 is set larger than the mass M22 of the mass member 221 of the other dynamic damper 202 (M21> M22). Further, the spring constant K21 of the elastic body 212 of one dynamic damper 201 is set smaller than the spring constant K22 of the elastic body 222 of the other dynamic damper 202 (K21 <K22).

  By setting the mass and spring constant as described above, the low frequency component f21 [f21 = (1 / 2π) √ (K21 / M21)] in the engine starting region can be reduced by one dynamic damper 201. Further, since the high-frequency component f22 [f22 = (1 / 2π) √ (K22 / M22)] in the engine starting region can be reduced by the other dynamic damper 202, for example, as shown in the graph of FIG. The frequency range of the dynamic damper effect can be expanded.

  In the two dynamic dampers 201 and 202 shown in FIG. 4, the mass members 211 and 221 are ring-shaped members having a diameter larger than that of the secondary flywheel 12, similarly to the mass member 21 shown in FIG. 2. In addition, the elastic bodies 212 and 222 are arranged at four locations in the circumferential direction, similarly to the elastic body 22 of FIG.

  In the example of FIG. 4, an example in which two dynamic dampers 201 and 202 are provided in parallel on the outer periphery of the secondary flywheel 12 is shown, but three or more dynamic dampers having different characteristics are connected to the secondary flywheel 12. You may provide in parallel with the outer periphery.

-Another example of dynamic damper-
Another example of the dynamic damper provided in the secondary flywheel 12 will be described with reference to FIG.

  In this example, two mass members 231 and 233 and two elastic bodies 232 and 234 are used, and these mass members 231 and 233 and elastic bodies 232 and 234 are placed on the outer periphery of the secondary flywheel 12 [elastic body 234 → mass. It is characterized in that the two dynamic dampers 203 and 204 are configured by connecting them in series in the order of the member 233 → the elastic body 232 → the mass member 231].

  Specifically, the mass member 231 and the elastic body 232 on the side far from the secondary flywheel 12 constitute one dynamic damper 203. Further, the mass member 231 far from the secondary flywheel 12, the elastic body 232, and the mass member 233 near the secondary flywheel 12, and the elastic body 234 near the secondary flywheel 12, make one A dynamic damper 204 is configured.

  6, the mass of the mass member 231 is M31, the spring constant of the elastic body 232 is K31, and the mass of the composite mass member 230 is [the mass M31 of the mass member 231 + the mass M32 of the elastic body 232 + the mass M33 of the mass member 233]. Assuming that the spring constant K32 of the elastic body 234 is given, the high-frequency component f31 [f31 = (1 / 2π) √ (K31 / M31)]) in the engine starting region is obtained by the dynamic damper 203 composed of the mass member 231 and the elastic body 232. Can be reduced. Further, the low frequency component f32 [f32 = (1 / 2π) √ (K32 / (M31 + M32 + M33))] in the engine starting region can be reduced by the dynamic damper 204 formed of the composite mass member 230 and the elastic body 234. Therefore, the frequency region of the dynamic damper effect can be expanded.

  In the two dynamic dampers 203 and 204 shown in FIG. 6, the mass members 231 and 233 are ring-shaped members having a diameter larger than that of the secondary flywheel 12, similarly to the mass member 21 shown in FIG. 2. The elastic bodies 232 and 234 are arranged at four locations in the circumferential direction as in the elastic body 22 of FIG.

  In the example of FIG. 6, an example in which two dynamic dampers 201 and 202 are provided in series on the outer periphery of the secondary flywheel 12 is shown. However, three or more dynamic dampers having different characteristics are connected to the secondary flywheel 12. It may be provided in series on the outer periphery.

It is a front view showing an example of a dual mass flywheel to which the present invention is applied. It is XX sectional drawing of FIG. It is a graph which shows the change of a torque fluctuation transmission rate. It is principal part sectional drawing which shows the other example of the dynamic damper provided in a dual mass flywheel. It is a graph which shows the change of a torque fluctuation transmission rate. It is principal part sectional drawing which shows another example of the dynamic damper provided in a dual mass flywheel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dual mass flywheel 11 Primary flywheel 12 Secondary flywheel 12a Clutch friction surface 13 Torsion spring (elastic body)
14 Hub 15 Flange 2 Dynamic damper 21 Mass member 22 Elastic body

Claims (3)

In a dual mass flywheel comprising a primary flywheel coupled to an engine crankshaft and a secondary flywheel, wherein the primary flywheel and the secondary flywheel are coupled via an elastic body,
A dual mass flywheel characterized in that a dynamic damper comprising a mass member and an elastic body is provided on the secondary flywheel. The dual mass flywheel according to claim 1,
A dual mass flywheel, wherein a plurality of dynamic dampers having different characteristics are provided in parallel to the secondary flywheel. The dual mass flywheel according to claim 1,
In the secondary flywheel, elastic bodies and mass members are alternately and serially arranged, and a plurality of dynamic dampers having different characteristics are configured by the plurality of mass members and the plurality of elastic bodies. Dual mass flywheel.

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