JPH025141Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a flywheel for an internal combustion engine, and in particular, the flywheel is divided into two parts and connected by a spring member to absorb torque fluctuations. It concerns an absorption flywheel.

[Conventional technology]

Vehicle body vibration caused by vehicle engine vibration,
In order to reduce cabin noise, especially ride comfort and muffled noise at low speeds, it is necessary to reduce engine torque fluctuations (rotation fluctuations). Conventionally, in order to reduce engine torque fluctuations, the flywheel was divided into two parts, one flywheel was connected to the engine crankshaft, the other flywheel was connected to the power train system, and these two flywheels were connected to a single-stage system. Two-part flywheels connected via type coil springs, single-stage spiral springs, multi-stage parallel spiral springs, etc. are already known (for example, Japanese Utility Model Publication No. 19218/1982, Japanese Patent Application Laid-open No. 66542/1983). , Japanese Patent Publication No. 52-89000
Publication No.).

[The problem that the idea aims to solve]

However, in conventional two-split flywheels, the natural frequency of the vibration system consisting of the two flywheels and the spring member is usually lower than the engine idle rotation speed in order to absorb torque fluctuations in the low speed range. It was set in an area close to . Therefore, when the engine speed fluctuates and the engine speed decreases during idling or at low speeds, the flywheel vibration system causes a resonance phenomenon, which not only causes noise and vibration of the vehicle body, but also causes the torque transmission system to deteriorate. There was also a possibility that the durability of the spring member would be adversely affected.

In order to alleviate this problem, the spring constant of the spring member must be further reduced to further distance the natural frequency of the two-piece flywheel from the engine idle speed. For low spring constants of spring members, it is effective to use spiral springs, which have low rigidity, instead of coil springs.
In order to further reduce the natural frequency of the conventional torque fluctuation absorbing flywheel using a single-stage spiral spring or a multi-stage parallel spiral spring, there are the following problems.

First, in a single-stage spiral spring, if you increase the spring length in the same plane in order to lower the spring constant, the diameter of the spiral spring increases, making the flywheel larger and heavier. This poses a problem when installing it on a vehicle.

Further, in a multi-stage parallel spiral spring, it is not desirable to arrange the springs in parallel because the spring constant becomes larger than that of each spring.

Furthermore, if a spiral spring is manufactured by winding a linear spring material, residual stress already exists in the natural state, and elastic stress is added when the spring is elastically deformed during use, reducing the durability of the spring.

In order to alleviate the various problems mentioned above, the present invention has been developed to improve the spring constant of a spring member made of a spiral spring in a torque fluctuation absorbing flywheel using a spiral spring in order to increase the size of the flywheel and improve the durability of the spring member. The purpose of this invention is to reduce the natural frequency of a flywheel that absorbs torque fluctuations even further than before, without causing any reduction.

[Means to solve the problem]

According to the present invention, the above object is achieved by the following torque fluctuation absorbing flywheel. That is, a driving side flywheel and a driven side flywheel are arranged so as to be relatively rotatable on the same axis, and the driving side flywheel and the driven side flywheel are arranged around the axis of the flywheel. A planar first spiral spring whose one end is connected to the drive-side flywheel is connected via a spiral spring having a spiral shape, and the first spiral spring is formed separately from the first spiral spring. and a planar second spiral spring whose one end is connected to the driven flywheel, and the other end of which is connected to each other, and each spiral spring has a rectangular cross section. A torque fluctuation absorbing flywheel characterized by:

[Operation] The torque fluctuation absorbing flywheel of the present invention has the following features:
The spring member is composed of two series spirals. By using the two-stage series type, the spring constant of the spring member is 1/1 of the spring constant of a single-stage spiral spring.
2, the natural frequency of the torque fluctuation absorbing flywheel becomes 1/√2, which is significantly reduced. Therefore, the phenomenon of the engine idling speed being pulled into the torque fluctuation absorbing flywheel resonance speed is prevented or significantly reduced.

By making the spiral spring into a two-stage series type,
Compared to a single-stage spiral spring with the same spring constant, the outer circumferential diameter of the spiral is significantly reduced, and the outer diameter of the torque fluctuation absorbing flywheel can also be small. Therefore, when the spring constant of the spiral spring is reduced, the flywheel does not become larger or heavier, and on the contrary, it becomes possible to reduce the size and weight of the flywheel.

By arranging two spiral springs in series,
A two-stage series spiral spring can be manufactured by simply punching out each planar spring portion using a press or the like, and then connecting these parts, so that extremely efficient manufacturing is possible.

Furthermore, in the torque fluctuation absorbing flywheel of the present invention, which has a rectangular cross section, each planar portion of the spiral spring can be produced by punching out a flat spring steel plate.
Unlike a spring member made by rolling a straight spring wire into a spiral shape, no residual stress remains and durability during use is improved.

〔Example〕

Hereinafter, preferred embodiments of the torque fluctuation absorbing flywheel according to the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show a torque fluctuation absorbing flywheel according to an embodiment of the present invention, and the flywheel has a two-part structure including a driving side flywheel 1 and a driven side flywheel 2. . The drive-side flywheel 1 is fixed to the crankshaft 3 with flywheel bolts 4. Although not shown, the driven flywheel 2 is connected to a power train system via a clutch. The driving side flywheel 1 and the driven side flywheel 2 are arranged on the same axis 5,
The driven flywheel 2 is supported around the bearing portion 6 of the driving flywheel 1 so as to be relatively rotatable.

A space 7 is defined between the side surfaces of the driving flywheel 1 and the driven flywheel 2, and a spiral spring 8 is provided in the space 7.
is provided. The spiral spring 8 is formed in a spiral shape around the axis 5 of the flywheel. As shown in FIG. 3, the spiral spring 8 is made up of a connected body of a first flat spiral spring 9 and a second flat spiral spring 10 that is separate from the first spiral spring 9. . One end of the first spiral spring 9 on the inner diameter side or the outer diameter side (inner diameter side end 9a in the figure) is connected to the drive side flywheel 1.
It is fastened with screw 11. The second spiral spring 10 is composed of a spiral spring wound in the opposite direction to that of the first spiral spring 9, and is overlapped with the first spiral spring 9 in two stages, so that the first The spiral spring 9 is fastened to the driven flywheel 2 by screws 12 at the end on the same side as the drive flywheel 1 (the end 10a on the inner diameter side in the figure). and,
First spiral spring 9 and second spiral spring 10
are the ends 9b and 10 on the opposite side to the fastened side.
They are connected to each other by screws 13 at b. Through such a connection, the driving wheel 1 and the driven wheel 2 are connected to each other in a two-stage serially connected spiral spring 8.
are connected to each other so that torque can be transmitted in the circumferential direction. The spring constant of the spiral spring 8 in the torsional direction is set to be sufficiently low, and the torsional angular displacement of the spiral spring 8 until the spiral spring 8 is completely wound is set to be sufficiently large.

In addition, in the above description, the connection between the first spiral spring 9 and the second spiral spring 10 is made using the screw 1.
3, this connection is not limited to the screws 13, but may be made by adhesive or the like.

Further, the spiral spring 8 has a rectangular cross section. In the spiral spring 8 having a rectangular cross section, the first and second spiral springs 9 and 10 are each
It can be manufactured by press punching a flat spring steel plate.

In the torque fluctuation absorbing flywheel of the present invention configured as described above, since a series two-stage spiral spring 8 is used as a spring for connecting both flywheels, the spring constant is 1 compared to a single-stage spiral spring. /2, and the natural frequency of the vibration system constituted by the flywheels 1 and 2 and the spiral spring 8 can be easily set to a small value. For this reason, the flywheel natural frequency deviates from the idle speed,
Resonance phenomenon during idle operation or low load is suppressed.

Further, since the spiral spring 8 can be installed in a flat space between the drive side flywheel 1 and the driven side flywheel 2 around the axis 5 of the flywheel, a particularly large space is provided for installing the spring. There's no need. Furthermore, compared to a torque fluctuation absorbing flywheel using a single-stage spiral spring, the outer diameter of the flywheel can be made smaller for the same spring constant, and the torque fluctuation absorbing flywheel can be made smaller and lighter.

Furthermore, since the two-stage spiral spring 8 is connected in the middle with a screw 13, the first spiral spring 9 and the second spiral spring 10 are formed into planar spiral springs by press punching a flat plate material. Compared to manufacturing a three-dimensional integral spiral spring, the spiral spring 8 can be manufactured easily and suitable for mass production, and residual stress can be eliminated.

[Effect of idea]

As explained above, according to the torque fluctuation absorbing flywheel of the present invention, both flywheels of a bipartite flywheel are connected via a spiral spring, and the spiral spring is connected to a two-stage series of planar spiral springs. Because it is constructed from a connected structure, the spring constant can be easily set to a sufficiently low value (1/2 of the spring constant of a conventional single-stage spiral spring), and the natural frequency of the flywheel vibration system can be kept sufficiently low (compared to a conventional single-stage spiral spring). (1/√2) of the natural frequency of the torque fluctuation absorbing flywheel with a single-stage spiral spring, it is possible to prevent the resonance phenomenon of the flywheel system during idling operation or in a low load range.

In addition, since the spiral springs are connected in series in two stages, the outer diameter of the torque fluctuation absorbing flywheel of the present invention can be kept small compared to a torque fluctuation absorbing flywheel with a single stage spiral spring. The flywheel can be made smaller and lighter.

Also, since the cross section of the spiral spring is rectangular,
Each planar part of the two-stage connected spiral spring can be manufactured by press punching a flat plate, and when manufactured by press punching, it can be manufactured more efficiently and with less residual Since stress does not need to be generated, the durability of the spiral spring can be improved.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the right half of a torque fluctuation absorbing flywheel in cross section according to an embodiment of the present invention, and FIG. 2 is a bottom view of the spiral spring portion of the device shown in FIG. 1 viewed from direction A. FIG. 3 is an exploded perspective view of the spiral spring. DESCRIPTION OF SYMBOLS 1... Drive side flywheel, 2... Driven side flywheel, 8... Spiral spring, 9... First spiral spring, 10... Second spiral spring, 13... Screw.

Claims (1)

[Scope of utility model registration request] A driving side flywheel and a driven side flywheel are arranged so as to be relatively rotatable on the same axis, and the driving side flywheel and the driven side flywheel are swirled about the axis of the flywheel. A planar first spiral spring whose one end is connected to the drive-side flywheel is connected via a coiled spiral spring, and the first spiral spring is formed separately from the first spiral spring and has one end connected to the driving side flywheel. and a planar second spiral spring connected to the driven flywheel, and each spiral spring has a rectangular cross section. A flywheel that absorbs torque fluctuations.