JP2007139041A - Dynamic damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easy-to-manufacture dynamic damper having improved durability while developing vibration absorbing function in a normal rotation region of an engine and even in a rotation region beyond the normal rotation region where acceleration is greatly increased. <P>SOLUTION: The dynamic damper for a hollow propeller shaft comprises an outer pipe 4, a damper mass 5 arranged at the axial center thereof, and a mount rubber 6 laid between the damper mass 5 and the outer pipe 4 for elastically connecting one to the other. A stopper 3 is provided between the outer pipe 4 and the damper mass 5. The stopper 3 does not function in the normal rotation region of the hollow propeller shaft but it functions in a rotation region beyond the normal rotation region. While developing vibration absorbing function in the normal rotation region and in the rotation region beyond it in an axially perpendicular direction, the dynamic damper eliminates the unnecessary distortion of the mount rubber 6 for improved durability. It is easy to manufacture because the stopper 3 is simply provided on a conventional damper. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a dynamic damper for a hollow propeller shaft for improving quietness during driving of a vehicle, and more particularly, when a hollow propeller shaft exceeds a normal rotation range, a stopper is made to function and mount. The present invention relates to a dynamic damper that improves the durability of a mount rubber by preventing an excessive load from being applied to the rubber.

The dynamic damper is installed in the hollow propeller shaft that is used to transmit the driving force of the car, preventing vibration of the car body and improving the quietness when driving the car, and in addition to metal fatigue caused by vibration of the hollow propeller shaft itself. This is to prevent the accompanying strength reduction. As shown in FIG. 7, the dynamic damper for the hollow propeller shaft is usually provided with an outer pipe 50, a damper mass 51 disposed on the axial center of the outer pipe 50, and between the damper mass 51 and the outer pipe 50. And at least a mount rubber 52 that elastically connects the two. This dynamic damper is installed in the hollow propeller shaft and absorbs vibrations generated during rotation of the hollow propeller shaft to prevent vibrations.
It is intended to eliminate vibration of the hollow propeller shaft.

However, as the engine speed increases, a load such as a large vibration is input to the mount rubber 52 of the dynamic damper mounted in the hollow propeller shaft, and the mount rubber 52 is greatly distorted and durability is lowered. Has occurred. The following techniques are known to deal with such a situation.
JP 2003-97633 A Japanese Patent Laid-Open No. 9-42375

As shown in FIG. 8, the dynamic damper of Patent Document 1 is provided with a constricted portion 53 at the center of a damper mass 51a, and the width W2 of the mount rubber 52a extending from the constricted portion 53 to the outer pipe 50a is illustrated. Therefore, even if a large vibration is input to the mount rubber 52a, the distortion of the mount rubber 52a can be reduced and the durability can be improved.

As shown in FIG. 9, the dynamic damper of Patent Document 2 has an outer pipe 50b connected to a damper mass 51b via a mount rubber 52b, and the mount rubber 52b has a plurality of connecting portions 54 provided at equal intervals. Between these connecting portions 54, a stopper 55 for limiting the eccentric amount between the damper mass 51b and the outer pipe 50b, and a circumferential stopper 56 for limiting the rotational displacement amount between the damper mass 51b and the outer pipe 50b are provided. Each is provided. In other words, in a steady state, since the x between the outer pipe 50b and the stopper 55 is sufficiently open, the stopper 55 does not function and the outer pipe 5
The rotational displacement of 0b is not hindered. On the other hand, the outer pipe 50b is a damper mass 51.
In an unsteady state in which a predetermined amount is deviated from b, the stopper 55 hits the circumferential stopper 56 and restricts the rotational displacement amount of the damper mass 51b and the outer pipe 50b. Therefore, it is possible to suppress input of a load such as excessive vibration in the rotation direction.

However, in the device described in Patent Document 1, the presence of the constricted portion 53 of the damper mass 51a causes the weight balance to be on both sides. As a result, resonance in the twisting direction is induced, and the amplitude magnification in the target frequency region The vibration of the target hollow propeller shaft cannot be reduced sufficiently. As a result, a large vibration is input to the mount rubber 52a, so that the mount rubber 52a is greatly distorted and the durability thereof cannot be improved so much.

Moreover, the thing of patent document 2 can suppress the input of load, such as an excessive vibration of a rotation direction, although a stopper function does not work in a steady state and a stopper function works in an unsteady state. It only suppresses input of loads such as excessive vibration in the rotational direction, and is not for vibration isolation in the direction perpendicular to the axis of the dynamic damper.

Therefore, the object of the present invention is to sufficiently perform the vibration isolating function in the direction perpendicular to the axis in the normal rotation range of the engine, and even if the acceleration greatly increases as the engine speed increases, An object of the present invention is to provide a dynamic damper that performs a vibration isolating function in a right angle direction, has sufficient durability, and is easy to manufacture.

The present invention has been proposed in order to achieve the above object, and is characterized by having the following configuration.
That is, according to the present invention, an outer pipe, a damper mass disposed at the axial center of the outer pipe, a mount rubber that is interposed between the damper mass and the outer pipe and elastically connects both, A dynamic damper for a hollow propeller shaft having at least a stopper provided between the outer pipe and the damper mass so that the stopper does not function within a normal rotation range of the hollow propeller shaft. A dynamic damper is provided in which the stopper is made to function when the rotation range is exceeded.

Further, according to the present invention, the stopper includes a fixing portion and a contact portion, the fixing portion is fixed to the outer pipe, and when the contact portion exceeds the normal rotation range of the hollow propeller shaft. The dynamic damper is provided so as to abut on the damper mass.

Further, according to the present invention, the stopper includes a fixing portion and a contact portion, the fixing portion is fixed to the damper mass, and when the contact portion exceeds the normal rotation range of the hollow propeller shaft. The dynamic damper is provided so as to contact the outer pipe.

In addition, according to the present invention, there is provided the dynamic damper, wherein the stopper is configured as a separate body and is fixed to the outer pipe.

Moreover, according to this invention, the said dynamic damper which comprised the said stopper separately and was made to adhere to the said damper mass is provided.

In addition, according to the present invention, there is provided the dynamic damper in which the fixed portion and the contact portion of the stopper are integrally formed.

In addition, according to the present invention, there is provided the dynamic damper in which the fixed portion and the contact portion of the stopper are integrally formed.

In addition, according to the present invention, the dynamic damper is provided in which the contact portion of the stopper is higher in hardness than the mount rubber.

In the dynamic damper of the present invention, since the stopper does not function when the hollow propeller shaft is in the normal rotation range, only the expected distortion occurs in the mount rubber. Furthermore, since the stopper functions when the normal rotation range is exceeded, no further distortion occurs in the mount rubber, and unexpected distortion does not occur. Therefore, while maintaining the anti-vibration function in the direction perpendicular to the axis in the normal rotation range of the engine, even if the acceleration greatly increases, the same anti-vibration function is achieved and the distortion is suppressed as expected. Therefore, it has sufficient durability. Moreover, it is easy to manufacture because it only has a stopper in terms of structure.

In addition, the dynamic damper of the present invention causes the mount rubber to be distorted more than before if it exceeds the normal rotation range of the hollow propeller shaft, but the contact portion of the stopper fixed to the outer pipe contacts the damper mass. Will not distort any further. Therefore,
The above effects can be fully enjoyed.

In addition, the dynamic damper of the present invention causes the mount rubber to be distorted more than before if it exceeds the normal rotation range of the hollow propeller shaft, but the contact portion of the stopper fixed to the damper mass contacts the outer pipe. Will not distort any further. Therefore,
The above effects can be fully enjoyed.

In addition, the dynamic damper of the present invention is formed by elastically connecting the damper mass and the outer pipe by means of a mount rubber, and constituting the dynamic damper by fixing a separate stopper to the outer pipe. Therefore, in addition to the above effects, the clearance between the stopper and the damper mass can be greatly released due to manufacturing restrictions and can be set freely.

In addition, the dynamic damper of the present invention is formed by elastically connecting the damper mass and the outer pipe by a mount rubber so as to be integrated, and a separate stopper is fixed to the damper mass to constitute the dynamic damper. Therefore, in addition to the above effects, the clearance between the stopper and the outer pipe can be greatly released due to manufacturing restrictions and can be set freely.

Further, the dynamic damper of the present invention is easy to manufacture because the fixing portion and the abutting portion of the stopper are integrally formed.

In addition, since the contact portion of the stopper of the dynamic damper of the present invention is higher than the hardness of the mount rubber, the mount rubber is moved after the contact portion of the stopper comes into contact when exceeding the normal rotation range of the hollow propeller shaft. The degree of distortion is greatly reduced.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

1 is a perspective view showing a dynamic damper of the present invention, FIG. 2 is a perspective view showing a dynamic damper of a conventional configuration, FIG. 3 is a sectional view of the dynamic damper of FIG. 2, and FIG. 4 is a perspective view showing a stopper of the present invention. FIG. 5 is a cross-sectional view of the dynamic damper of the present invention.
In these drawings, a dynamic damper 1 according to the present invention is mounted inside a hollow propeller shaft. A conventional dynamic damper (hereinafter simply referred to as a damper) 2 shown in FIGS. 2 and 3 is provided with a stopper 3 according to the present invention. Is fixed by press-fitting.

As shown in FIG. 2, the damper 2 is interposed between the outer pipe 4, the damper mass 5 disposed on the axial center of the outer pipe 4, and the damper mass 5 and the outer pipe 4, so that both are elastic. And at least a mount rubber 6 to be connected.

The material of the outer pipe 4 may be made of metal, and iron metal is usually used. Since the damper mass 5 requires a certain amount of weight, cast iron and steel are often used from the viewpoint of economy. The mount rubber 6 is made of SBR (styrene / butadiene copolymer synthetic rubber), natural rubber, or a mixture thereof.

The outer pipe 4 has a cylindrical shape. The damper mass 5 has a shape having a hole 11 in the disk 10, but this hole 11 is not an essential condition. As shown in FIG. 3, the mount rubber 6 that elastically connects the outer pipe 4 and the damper mass 5 includes a pipe-side base 12 that covers the inner peripheral surface of the outer pipe 4, and the outer periphery of the damper mass 5. Mass side base 13 covering the surface
And five standing portions 14 that connect the pipe-side base 12 and the mass-side base 13. These five standing portions 14 are provided at equal intervals, that is, every 360 degrees / 5 = 72 degrees. Therefore, between the five standing portions 14, the outer pipe 4 and the damper mass 5 are surrounded by 5
A number of windows 15 are created. The standing portion 14 is not limited to five, but three, four,
There is no problem even if there are six or more. However, stopper 3 described in detail later
Therefore, about 5 or 6 standing portions 14 are ideally natural. Further, rubber 16 is attached to the outer peripheral surface of the outer pipe 4, which is to press fit into the hollow propeller shaft.

The stopper 3 constitutes an important structure of the present invention, and includes a fixing portion 20 and a contact portion 21 as shown in FIG. The fixing portion 20 is for fixing to the outer pipe 4, and a ring 22 that can be fixed to the outer pipe 4 is provided with five insertion pieces 23 that can be inserted into the five windows 15 of the outer pipe 4. It is. Furthermore, the abutting portion 21 stops distortion of the standing portion 14 of the mount rubber 6 that exceeds the allowable range, and includes the insertion piece 23 and the ring 2.
2 is provided on the inner peripheral surface. The shape of the contact portion 21 is not particularly limited. For example, the contact surface of the tip may be flattened to increase the contact area, and the device may be devised to reduce distortion in the contact direction.

The stopper 3 having the above configuration is press-fitted and fixed to the damper 2. That is, the inner peripheral surface of the outer pipe 4 of the damper 2 is covered with the pipe side base 12 of the mount rubber 6,
Since the outer diameter of the ring 22 of the stopper 3 is formed slightly larger than the inner diameter, the stopper 3 is pressed into the damper 2 by positioning so that the insertion piece 23 of the stopper 3 can be inserted into the window 15 of the damper 2. If it goes, it can fix, and will constitute the dynamic damper 1 of the present invention. At this time, the clearance C within the allowable range of distortion of the standing portion 14 of the mount rubber 6 between the contact portion 21 of the stopper 3 and the mass side base portion 13 of the damper mass 5 is, for example, 0.1 mm to 1.mm. 1 mm is given. The specific clearance C is determined by the normal rotation range of the hollow propeller shaft, the extent of the rotation range exceeding the normal rotation range, and the material of the mount rubber 6.

When the hollow propeller shaft exceeds the normal rotation range, the stopper function works. That is, when the distortion of the standing portion 14 exceeds the allowable clearance C, the contact portion 21 is mounted rubber on the damper mass 5. 6 is in contact with the mass side base portion 13 so that the distortion of the standing portion 14 does not progress any more, the durability of the mount rubber 6 is ensured, and the quietness of the hollow propeller shaft is also maintained. Conversely, if it is within the normal rotation range, the stopper function does not work, that is,
Since the distortion of the standing portion 14 is within the clearance C, the abutting portion 21 does not abut against the damper mass 5 and maintains the quietness of the hollow propeller shaft.

Since this stopper 3 is configured separately from the damper 2, it suffices to fix the stopper 3 separately to the damper 2, and therefore the clearance C between the stopper 3 and the damper mass 5.
Can be freed from manufacturing restrictions and can be set freely. It should be noted that it may be integrally manufactured in a shape in which the stopper 3 is incorporated in the damper 2 in advance.
However, as described above, since the clearance C is from 0.1 mm to 1.1 mm, it is necessary to match the mold to manufacture it integrally, which reduces the durability of the mold and reduces the cost. It becomes a factor of up.

Further, in this embodiment, the stopper 3 is formed by vulcanizing and bonding a rubber contact portion 21 to a metal fixing portion 20, but the fixing portion 20 and the contact portion 21 are integrally formed. Also good. In that case, the stopper 3 is made of metal and is integrally formed by casting or sintering, or resin and injection molding. The stopper 3 is preferably made of nylon containing glass fiber or carbon fiber, and can be easily manufactured by forming it integrally. The contact portion 21 of the stopper 3 is desirably higher than the hardness of the mount rubber 6. The reason is that when the hollow propeller shaft exceeds the normal rotation range, the abutting portion 21 abuts against the damper mass 5, but since the abutting portion 21 is hard, it is difficult to deform in the abutting direction. This is because the degree to which the installation portion 14 is further distorted is reduced.

Next, the operation of the dynamic damper 1 configured as described above will be described.
First, the dynamic stopper 1 is manufactured by press-fitting and fixing a separate stopper 3 to the damper 2. Next, the dynamic damper 1 is mounted on the hollow propeller shaft. And
If the hollow propeller shaft rotates and is within the normal rotation range, for example, 5000 rpm, the erected portion 14 of the mount rubber 6 is less distorted and falls within the clearance C range. Without contacting the damper mass 5, the quietness of the hollow propeller shaft is maintained. On the other hand, when the rotation of the hollow propeller shaft exceeds the normal rotation range, for example, 7000 rpm, the distortion of the standing portion 14 of the mount rubber 6 increases and comes out of the clearance C range. 21 abuts against the damper mass 5 so that the distortion of the standing portion 14 of the mount rubber 6 does not progress any further, ensuring the durability of the mount rubber 6 and maintaining the quietness of the hollow propeller shaft.

In addition, since it tested about the performance of the dynamic damper 1 of this invention, the condition is demonstrated.
<Test Example 1>
Acceleration: 2.0 G is input to the dynamic damper 1 of the present invention, the frequency characteristics at that time,
That is, the resonance frequency and phase are measured.
<Comparative example 1>
Acceleration: 2.0 G is input to the damper 2 of the conventional configuration, and the frequency characteristics at that time, that is,
Measure the resonance frequency and phase.
As a result, the resonance frequency in Test Example 1 was 143 Hz, whereas the resonance frequency in Comparative Example 1 was 141.5 Hz. There was almost no difference in phase.

<Test Example 2>
The durability of the upright portion 14 of the mount rubber 6 is examined when an acceleration of 10.0 G is input to the dynamic damper 1 of the present invention and the number of times is 50 million.
<Comparative example 2>
The acceleration of 10.0 G is input to the damper 2 of the conventional configuration, and the durability of the standing portion 14 of the mount rubber 6 is observed at the frequency of 50 million times.
As a result, the change in the standing portion 14 of the mount rubber 6 was not observed even after 50 million times in the test example 2, whereas the mount rubber in the comparative example 2 was 17 million times later. 6 standing part 1
4 cracked.

In the dynamic damper 1 of the first embodiment, the stopper 3 is press-fitted and fixed to the inner peripheral surface of the outer pipe 4 of the damper 2 of FIG.
The dynamic damper 1a of Example 2 obtained by press-fitting and fixing the stopper 3a to the outer peripheral surface of the damper mass 5 may be used. That is, the stopper 3a has a fixed portion 20a and a contact portion 21a.
It consists of. The fixing portion 20a is for fixing to the damper mass 5, and the insertion piece 2 that can be inserted into the five windows 15 of the outer pipe 4 into the ring 22a that can be fixed to the damper mass 5.
Five 3a are provided. Further, the abutting portion 21a stops the distortion of the standing portion 14 of the mount rubber 6 exceeding the allowable range, and the inserting piece 23a and the ring 2 of the fixing portion 20a.
2a is provided on the outer peripheral surface.

The stopper 3a having the above configuration is press-fitted and fixed to the damper 2. That is, the outer peripheral surface of the damper mass 5 of the damper 2 is covered with the mass side base 13 of the mount rubber 6, and the inner diameter of the ring 22a of the stopper 3a is formed slightly smaller than the outer diameter thereof. 15, the insertion piece 23 a of the stopper 3 a is positioned so as to be inserted, and the stopper 3 can be fixed by being press-fitted into the damper 2, thereby constituting the dynamic damper 1 a according to the second embodiment of the present invention. become. At that time, the contact portion 21a of the stopper 3a
A clearance C <b> 1 similar to that of the first embodiment is provided between the damper mass 5 and the mass side base 13 of the damper mass 5. Since other configurations and operations are the same as those of the dynamic damper 1 of the first embodiment, the description thereof is omitted.

As mentioned above, although Example 1 and 2 of this invention were demonstrated, it should be understood that a concrete structure is not limited to this and the change in the range which does not deviate from the summary of this invention is possible suitably. .

The dynamic damper according to the present invention is not limited to the vibration isolating function in the normal rotation range of the engine, and is highly applicable when the vibration isolating function and durability at a high speed rotation are required. If you want to make without, the availability is very high.

(Example 1) which is a perspective view which shows the dynamic damper of this invention. It is a perspective view which shows the dynamic damper of a conventional structure (Example 1). FIG. 3 is a sectional view of the dynamic damper of FIG. 2 (Example 1). It is a perspective view which shows the stopper of this invention (Example 1). It is sectional drawing of the dynamic damper of this invention (Example 1). (Example 2) which is sectional drawing of the other dynamic damper of this invention. It is sectional drawing which shows an example of the conventional dynamic damper. It is sectional drawing which shows an example of the other conventional dynamic damper. It is the side view which notched a part which shows an example of the conventional dynamic damper.

Explanation of symbols

1,1a Dynamic damper 2 Conventional configuration of dynamic damper (damper)
3, 3a, 55 Stopper 4, 50, 50a, 50b Outer pipe 5, 51, 51a, 51b Damper mass 6, 52, 52a, 52b Mount rubber 10 Disk 11 Hole 12 Pipe side base 13 Mass side base 14 Standing part 15 Window 20, 20a Adhering portion 21, 21a Abutting portion 22, 22a Ring 23, 23a Insertion piece 53 Constricted portion 54 Connecting portion 56 Circumferential stopper C, C1 Clearance W1, w2 Width x

Claims (7)

A hollow propeller comprising at least an outer pipe, a damper mass disposed on the axis of the outer pipe, and a mount rubber that is interposed between the damper mass and the outer pipe and elastically connects the two. A dynamic damper for a shaft, wherein a stopper is provided between the outer pipe and the damper mass so that the stopper does not function within the normal rotation range of the hollow propeller shaft, and when the normal rotation range is exceeded, A dynamic damper that features a stopper function. The stopper includes a fixing portion and a contact portion, and the fixing portion is fixed to the outer pipe, and the contact portion contacts the damper mass when the hollow propeller shaft exceeds the normal rotation range. The dynamic damper according to claim 1. The stopper includes a fixing portion and a contact portion, and the fixing portion is fixed to the damper mass, and the contact portion contacts the outer pipe when the hollow propeller shaft exceeds the normal rotation range. The dynamic damper according to claim 1. The dynamic damper according to claim 2, wherein the stopper is configured separately and is fixed to the outer pipe. The dynamic damper according to claim 3, wherein the stopper is configured as a separate body and is fixed to the damper mass. The dynamic damper according to any one of claims 2 to 5, wherein the fixed portion and the contact portion of the stopper are integrally formed. The dynamic damper according to claim 2, wherein a contact portion of the stopper is higher than a hardness of the mount rubber.

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