JPH0571502U - Dynamic damper - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a dynamic damper which is advantageous in reducing the spring constant in the direction perpendicular to the axis while ensuring the rigidity in the swing direction. [Structure] This dynamic damper comprises a cylindrical rubber fixing member 1 fixed to a rotary shaft 4, a ring-shaped mass member 2, and an elastic member 3 elastically supporting the mass member 2. .. The elastic member 3 is formed with an arcuate outer concave portion 3e and an inner concave portion 3f having different phases in the circumferential direction. As a result, the elastic member 3 is formed with the outer arm portion 31 located radially outside and the inner arm portion 32 located radially inside in the radial direction. Outer arm 31
The inner arm portions 32 are alternately connected with different phases in the circumferential direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dynamic damper. This dynamic damper can be applied to, for example, drive shafts and propeller shafts of automobiles.

[0002]

[Prior Art]

 Dynamic dampers are often used to suppress harmful vibrations of the rotating shaft. This dynamic damper converts the energy of the harmful vibration of the rotary shaft into the resonance energy of the mass member and attenuates it by matching the resonance frequency with the frequency of the harmful vibration.

As shown in FIGS. 5A and 5B, such a dynamic damper is provided with a cylindrical fixing member 110 fixed to the rotating shaft 100 and an inner diameter larger than the outer diameter of the rotating shaft 100. A ring-shaped mass member 120 arranged on the outer peripheral side of the shaft 100, and an elastic member 130 made of a rubber material which is arranged at a predetermined interval in the circumferential direction and elastically supports the mass member 120. It is known that a recess 131 is provided between 130 to form a stopper 132. In this dynamic damper, when a harmful vibration in the direction perpendicular to the axis occurs in the rotary shaft 100, the mass member 120 resonates in the resonance frequency range and the harmful vibration is suppressed. Here, the resonance frequency of the dynamic damper is basically determined by the mass of the mass member 120 and the spring constant of the elastic member 130 in the vibration direction.

In the dynamic damper described above, in order to set the resonance frequency in the low frequency range, it is necessary to reduce the spring constant of the elastic member 130 or increase the mass of the mass member 120. The latter is not preferable because the weight increases. Also, in the former case, in order to reduce the spring constant of the elastic member 130, a means of lengthening the elastic member 130 in the radial direction can be adopted, but this leads to an increase in the outer diameter of the dynamic damper, and in terms of mounting space. It is a disadvantage.

Further, in order to keep the resonance frequency in the low frequency range while reducing the outer diameter of the dynamic damper, the elastic member 130 has a small thickness A in the axial direction and a small width B in the circumferential direction. It is possible to reduce the spring constant. However, although the spring constant in the direction perpendicular to the axis (arrow Y1 direction) is reduced, on the other hand, the elastic member 130 is also softened in the swinging direction (X1 direction), and swinging occurs at resonance. As a result, good resonance in the axial direction is impaired, which is disadvantageous in suppressing harmful vibration.

As disclosed in Japanese Utility Model Laid-Open No. 60-47939, a dynamic damper is composed of a fixing member, a mass member, and a plurality of arm-shaped elastic members connecting the both, and is arranged in the circumferential direction. It is also known that adjacent arm-shaped elastic members are arranged alternately in the axial direction of the rotating shaft.

[0007]

[Problems to be solved by the device]

 An object of the present invention is to provide a dynamic damper which is advantageous in reducing the spring constant in the direction perpendicular to the axis while ensuring the rigidity in the swing direction.

[0008]

[Means for Solving the Problems]

 The dynamic damper of the present invention comprises a fixed member fixed to the rotating shaft, a ring-shaped mass member arranged radially outside the fixed member, and an elastic member integrally connecting the mass member and the fixed member. It is characterized in that the elastic member is composed of arms that are arranged in at least two stages in the radial direction and are connected to each other, and that adjacent arms in the radial direction are arranged alternately in the circumferential direction. It is characterized by.

[0009]

[Action]

 When the harmful vibration acts on the rotary shaft, the elastic member acts as a spring in the resonance frequency range and the mass member resonates, thereby suppressing the harmful vibration. In the dynamic damper of the present invention, the elastic member is composed of arms arranged in at least two stages in the radial direction, and adjacent arms in the radial direction are arranged alternately in the circumferential direction. Therefore, the elastic member is easily bent in the axis-perpendicular direction, and the spring constant in the axis-perpendicular direction is kept small.

[0010]

【Example】

 An embodiment of the present invention will be described with reference to FIGS. (Structure) This dynamic damper is composed of a cylindrical fixing member 1, a ring-shaped mass member 2 and an elastic member 3. The fixing member 1 is made of a rubber material and has an insertion hole 10 penetrating in the axial direction and a ring groove 11 formed on the outer peripheral surface. By inserting the insertion hole 10 into the rotary shaft 4, the fixed member 1 is arranged on the outer peripheral side of the rotary shaft 4, and the fixed member 1 is fixed to the rotary shaft 4 by the band tool 12 directed to the ring groove 11. ..

The mass member 2 is made of metal, and its inner diameter is larger than the outer diameter of the rotary shaft 4. The mass member 2 is covered with a rubber film 30 integral with the elastic member 3. The elastic member 3 is made of a rubber material that integrally connects the mass member 2 and the fixed member 1 and elastically supports the mass member 2. As shown in FIG. 1, on the surface portion 3a of the elastic member 3, a plurality of deep groove-shaped outer concave portions 3e are formed in an arc shape at a predetermined interval in the circumferential direction and substantially concentrically with the fixing member 1. There is. Further, on the surface portion 3a of the elastic member 3, a plurality of deep groove-shaped inner concave portions 3f are arranged radially inward of the outer concave portion 3e at predetermined intervals in the circumferential direction and are substantially concentric with the fixing member 1. Individually formed. Similarly, an outer recess 3e and an inner recess 3f are also formed on the back surface 3b of the elastic member 3, respectively. Here, as can be understood from FIG. 1, the outer concave portion 3e and the inner concave portion 3f have different phases in the circumferential direction and are staggered in the circumferential direction.

As a result, the elastic member 3 includes four outer arm portions 31 connected to each other in the circumferential direction in the middle of the radial direction and located on the radially outer side, and four inner arm portions located on the radially inner side. And 32 are formed. Here, as can be understood from FIG. 1, the outer arm portion 31 and the inner arm portion 32 have different phases in the circumferential direction, and thus are arranged alternately in the circumferential direction.

In this example, four outer arm portions 31 and four inner arm portions 32 are formed, but the number of outer arm portions 31 and inner arm portions 32 is not limited to this, and other numbers may be used. As shown in FIG. 2, in the elastic member 3, the rubber portion in which the outer concave portion 3e is formed is a thin film portion 3n, and the rubber portion in which the inner concave portion 3f is formed is a thin film portion 3m. The thickness of 3 m is about 1 mm 2.

In the embodiment described above, the spring constant of the elastic member 3 and the mass of the mass member 2 in the direction perpendicular to the axis are set so as to obtain a desired resonance frequency. Therefore, when the harmful vibration in the direction perpendicular to the axis acts on the rotary shaft 4, the elastic member 3 acts as a spring in the resonance frequency range, and the mass member 2 resonates in the direction perpendicular to the axis, as in the conventional case, which causes harmful effect. Vibration is suppressed.

(Effect) In the present embodiment, the outer arm portions 31 and the inner arm portions 32, which constitute the elastic member 3 that functions as a spring that elastically supports the mass member 2, are arranged alternately in the circumferential direction. Therefore, even if the thickness D (see FIG. 2) of the elastic member 3 in the axial direction is set to be large, the spring constant in the direction perpendicular to the axis can be reduced. Therefore, it is advantageous for reducing the outer diameter of the mass member 2 and thus the dynamic damper, and is suitable when there is a restriction on the mounting space.

Further, in this embodiment, since the thickness D in the axial direction of the elastic member 3 can be increased while reducing the spring constant as described above, the swinging direction of the elastic member 3 (arrow X1 shown in FIG. 2). (Direction) rigidity can be secured. (Other Examples) In the above-described embodiment, the outer recess 3e and the inner recess 3f are not penetrated in the axial direction of the elastic member 3, but in some cases, as shown in FIG. 3, the outer recess 3e and the inner recess 3e are not penetrated. It is also possible to make 3f penetrate in the axial direction of the elastic member 3.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings. For example, the shapes and the numbers of the outer arm portions 31 and the inner arm portions 32, the outer recesses 3e, and the inner recesses 3f are defined. The shape and the number can be changed, etc., and can be appropriately changed as necessary without departing from the gist. (Application Example) FIG. 4 shows an application example of the above-described embodiment. This example is applied to a front engine / front drive type drive device that transmits the rotation of a horizontally installed engine 80 to left and right wheels 86 and 87 via a clutch, a transmission 82, a differential gear, and drive shafts 84 and 85. Is. In this system, since the propeller shaft is not provided, the vibration generated in the engine 80 is easily transmitted to the drive shaft. In this example, the above-mentioned dynamic damper is attached to the drive shaft 84 having a long axial length where vibration is likely to occur.

[0018]

[Effect of the device]

 According to the dynamic damper of the present invention, the elastic member is composed of arms that are arranged in at least two stages in the radial direction and are connected to each other, and adjacent arms in the radial direction are staggered in the circumferential direction. .. Therefore, even if the thickness of the elastic member in the axial direction is set large, the spring constant in the direction perpendicular to the axis can be reduced. Therefore, it is advantageous for downsizing the outer diameter of the mass member, and thus the dynamic damper, and is suitable when the mounting space is restricted.

Further, according to the dynamic damper of the present invention, since the elastic constant can be set large while the spring constant in the direction perpendicular to the axis is small, the rigidity in the swinging direction can be increased.

[Brief description of drawings]

FIG. 1 is a front view showing a state in which a dynamic damper is attached to a rotary shaft.

FIG. 2 is a sectional view taken along line WW of FIG.

FIG. 3 is a cross-sectional view of a main part of a dynamic damper according to another example.

FIG. 4 is a configuration diagram showing an example applied to a vehicle drive device.

5A is a cross-sectional view of a conventional dynamic damper attached to a rotary shaft, and FIG. 5B is a front view thereof.

[Explanation of symbols]

In the figure, 1 is a fixing member, 2 is a mass member, 3 is an elastic member, 3
e is an outer concave portion, 3f is an inner concave portion, 31 is an outer arm portion, 32
Indicates the inner arm.

Claims (1)

[Scope of utility model registration request] 1. A fixing member fixed to a rotary shaft, a ring-shaped mass member arranged radially outside of the fixing member, and an elastic member integrally connecting the mass member and the fixing member. The elastic member is composed of arms that are arranged in at least two stages in the radial direction and are connected to each other, and adjacent arms in the radial direction are staggered in the circumferential direction. Dynamic damper.