JP5887726B2 - Method of setting dynamic damper for vehicle and mounting structure of dynamic damper for vehicle - Google Patents

Description

  The present invention relates to a method for setting a dynamic damper for a vehicle attached to the vehicle constituent member in order to suppress vibration of the vehicle constituent member, and an attachment structure for the dynamic damper for the vehicle.

  In a front engine rear drive type (FR type) or four-wheel drive type vehicle, a propeller shaft for transmitting power from a power source such as an engine, a transmission, or an electric motor to a rear wheel extends in the vehicle front-rear direction. This propeller shaft may resonate with vibrations transmitted from the power source or the like, thereby causing a problem of generating noise.

  In order to solve this problem, as disclosed in Patent Document 1, for example, a dynamic damper having a mass body and an elastic body may be attached to the propeller shaft. In this case, the characteristics of the dynamic damper, such as the characteristics of the dynamic damper, such that the set frequency of the dynamic damper (the frequency that causes a downward peak in the vibration level waveform of the propeller shaft by attaching the dynamic damper) matches the resonance frequency Fa of the propeller shaft. Specifically, characteristics such as the mass of the mass body constituting the dynamic damper or the spring constant or damping coefficient of the elastic body are set, thereby effectively reducing the level of resonance vibration of the propeller shaft. .

  This will be specifically described with reference to FIG. The vibration level of the propeller shaft to which the dynamic damper is not attached has a waveform in which a peak P1 is formed at the resonance frequency Fa, for example, as indicated by reference numeral A in FIG. On the other hand, when a dynamic damper whose characteristics are set so that the set frequency matches the resonance frequency Fa of the propeller shaft is attached, for example, as shown by reference numeral B in FIG. A downward peak P2 is formed at the resonance frequency Fa, and resonance waveforms w1 and w2 having relatively small peaks on the low frequency side and the high frequency side across the resonance frequency Fa are formed. The maximum value of the vibration level can be effectively reduced as compared with the case where the dynamic damper is not attached.

JP-A-11-72143

  However, when the dynamic damper is attached to the propeller shaft, as shown in FIG. 10B, the dynamic damper is not attached in the frequency region near the peaks of the two resonance waveforms w1 and w2 formed as described above. The vibration level increases from time to time. As a result, the noise caused by the resonance vibration of the propeller shaft is likely to be harsh on the low frequency side of the frequency range near the peaks of the two resonance waveforms w1 and w2.

  As one of the reasons that the low frequency range is more harsh, various noises such as engine and tire noise during high-speed driving are generated in the vehicle in the high frequency range. It is mentioned that noise caused by resonance is easily lost. As another reason, generally, the degree to which a person feels noise varies depending on the frequency, and the lower the frequency, the easier it is to hear. Therefore, it is required that the noise caused by the resonance vibration of the propeller shaft be suppressed more preferentially in a low frequency that is harsh to the passenger.

  In addition to the propeller shaft, the dynamic damper may be attached to the vehicle constituent member in order to suppress vibrations of various vehicle constituent members such as a drive shaft, and the same problem exists in these cases. .

  Therefore, an object of the present invention is to effectively reduce noise caused by resonance vibration of the vehicle component so that it is difficult for an occupant to feel when a dynamic damper is attached to the vehicle component.

  In order to solve the above-described problems, a vehicle dynamic damper setting method and a vehicle dynamic damper mounting structure according to the present invention are configured as follows.

First, the invention according to claim 1 of the present application is
To suppress the resonance vibration at the resonance frequency of the I Ri arising vehicle component to the vibration from the vibration source by being attached to said vehicle component, the vibration level for the frequency of the vibration, a low frequency side and high frequency On the other hand, there is provided a vehicle dynamic damper setting method for forming a resonance waveform having a peak lower than a vibration level peak at the resonance frequency ,
The upper line of the vibration level for the frequency of vibration of the vehicle structure member, and the low frequency side is lower than the high frequency side, the peak of the vibration level at the resonance frequency of the vehicle component when not provided with the dynamic damper Upper limit line setting process to set to be lower than ,
A dynamic damper setting step for setting the dynamic damper so that a vibration level of a peak of the resonance waveform on the low frequency side and the high frequency side in the vehicle constituent member is equal to or lower than the upper limit line ;
It is characterized by having .

According to a second aspect of the present invention, in the vehicle dynamic damper setting method according to the first aspect,
In the dynamic damper setting step, the dynamic damper is set so that the vibration level at the peak of the resonance waveform on the low frequency side is lower than the vibration level at the peak of the resonance waveform on the high frequency side. Features.
The invention according to claim 3
When the first and second dynamic dampers are attached to the vehicle constituent member in order to suppress the vibration of the vehicle constituent member that resonates with the vibration from the vibration source, the first and second dynamic dampers are set. A dynamic damper setting method,
Setting the characteristics of the first dynamic damper so that the set frequency of the first dynamic damper is set to be lower than the resonance frequency of the vehicle component;
The setting frequency of the second dynamic damper is set to the peak frequency of the resonance waveform formed on the low frequency side with the first dynamic damper being sandwiched by attaching the first dynamic damper to the vehicle component. The characteristics of the second dynamic damper are set so that they are equal to each other or set to the lower frequency side.

Furthermore, according to 請 Motomeko 4 invention, for suppressing the resonance at the resonance frequency of the I Ri arising vehicle component to the vibration from the vibration source by being attached to said vehicle component, vibration A vehicle dynamic damper setting method for forming a resonance waveform having a vibration level with respect to a frequency having a peak lower than a vibration level peak at the resonance frequency on a low frequency side and a high frequency side ,
The upper line of the vibration level for the frequency of vibration of the vehicle structure member, and the upper-limit line setting step of setting as the low frequency side becomes lower than the high frequency side,
The frequency of the downward peak occurring between the low frequency side of the peak and the high frequency side of the peak in the resonance waveform of the vehicle component in a state with the dynamic damper, the vehicle structure when not provided with the dynamic damper than the resonant frequency of the vibration level of the member becomes the maximum is set to the low frequency side, and the vibration level of the peak of the low frequency side and a resonant waveform of the high-frequency side in the vehicle component is less than the upper limit line A dynamic damper setting step for setting the dynamic damper,
It is characterized by having .
Furthermore, the invention according to claim 5 is the vehicle dynamic damper setting method according to claim 4,
In the dynamic damper setting step, as the inclination of the upper limit line is larger, the shift amount of the downward peak frequency to the low frequency side with respect to the resonance frequency is increased .
Furthermore, the invention according to claim 6 is a method for setting a dynamic damper for a vehicle that is attached to a vehicle component in order to suppress the vibration of the vehicle component that causes resonance vibration at a predetermined frequency due to vibration from a vibration source. Because
The upper limit value of the vibration level for the predetermined frequency in the vehicle component member is set so as to decrease as the vibration frequency decreases,
The setting frequency of the dynamic damper that forms the minimum value of the vibration level of the vehicle component in the state provided with the dynamic damper is set to a frequency at which the vibration level of the vehicle component becomes maximum when the dynamic damper is not provided. Is also set to the low frequency side,
The set frequency of the dynamic damper is set to a frequency such that the vibration level of the vehicle component is less than or equal to the upper limit value,
The dynamic damper includes a first dynamic damper and a second dynamic damper,
The set frequency in the first dynamic damper and the second dynamic damper is set to a lower frequency side than the frequency at which the vibration level of the vehicle constituent member is maximum when the dynamic damper is not provided; and
Each set frequency of the first dynamic damper and the second dynamic damper on the low frequency side is set to a frequency at which a vibration level of the vehicle component is equal to or less than the upper limit value.

  In the present specification, the term “dynamic damper set frequency” described in the above-mentioned claims means that the dynamic damper is attached to the vehicle component in the waveform of the vibration level with respect to the frequency of the vehicle component. It means the frequency at which a downward peak occurs.

  In this specification, the term “characteristics of the dynamic damper” described in the above claims refers to a dynamic damper such as a mass of a mass body constituting the dynamic damper or a spring constant or a damping coefficient of an elastic body. It means various characteristics that can adjust the set frequency.

First, according to the first aspect of the present invention, the vibration level of the vehicle constituent member is set so that the low frequency side has a high frequency by setting the dynamic damper attached to the vehicle constituent member in order to suppress the resonance vibration of the vehicle constituent member. Lower than the upper limit line set to be lower than the peak of the vibration level at the resonance frequency of the vehicle component when the dynamic damper is not provided . As a result, the vibration level is preferentially reduced in a low frequency range where it is easy for the occupant to feel noise. Therefore, it is possible to effectively reduce the noise caused by the resonance vibration of the vehicle component so that the occupant does not feel it easily. .
If the invention according to claim 2 is applied to the invention according to claim 1, the vibration level at the peak of the resonance waveform on the low frequency side is lower than the vibration level at the peak of the resonance waveform on the high frequency side. As described above, by setting the dynamic damper, it is possible to reduce the vibration level mainly in a low frequency range where it is easy for the passenger to feel noise.

According to the invention of claim 3 , the set frequency of the first dynamic damper attached to the vehicle component member to suppress the resonance vibration of the vehicle component member is lower than the resonance frequency of the vehicle component member. Therefore, in the waveform of the vibration level with respect to the frequency of the vehicle component, the resonance waveform peak formed on the low frequency side with the resonance frequency in between is formed on the high frequency side with the resonance frequency in between. It can be lower than the peak of the waveform. Therefore, as in the first aspect of the invention, the vibration level can be reduced mainly in the low frequency range where the passengers can easily feel noise. Further, since the set frequency of the second dynamic damper attached to the vehicle component is set equal to or lower than the peak frequency of the resonance waveform on the low frequency side, the second dynamic damper is set. A downward peak is also formed at the set frequency of the damper, and the peaks of the resonance waveforms formed on the low frequency side and the high frequency side across the set frequency of the second dynamic damper are assumed to be the first dynamic It becomes smaller than the peak of the resonance waveform on the low frequency side formed when only the damper is attached. Therefore, since the maximum value of the vibration level is further reduced in the low frequency range, it is possible to more effectively reduce the noise caused by the resonance vibration of the vehicle constituent member.

Also, according to the invention described in claim 4, the downward peak occurring between the serial low-frequency side of the peak and the high frequency side of the peak in the resonance waveform of the vehicle component in a state having a dynamic damper frequency ( set frequency of the dynamic damper) is by being set to the remote low frequency side by the resonant frequency of the vehicle component when the dynamic damper is not mounted, the vibration level of the waveform with respect to the frequency of the vehicle component, the resonant frequency The peak of the resonance waveform formed on the low frequency side across the resonance frequency can be made lower than the peak of the resonance waveform formed on the high frequency side across the resonance frequency, and the vibration level of the vehicle component is low. The frequency side is suppressed below the upper limit line set so as to be lower than the high frequency side . As a result, the vibration level is preferentially reduced in a low frequency range where it is easy for the occupant to feel noise. Therefore, it is possible to effectively reduce the noise caused by the resonance vibration of the vehicle component so that the occupant does not feel it easily. .
Further, when the invention according to claim 5 is applied to the invention according to claim 4, the larger the inclination of the upper limit line, the larger the deviation amount of the set frequency of the dynamic damper to the low frequency side with respect to the resonance frequency is set. By doing so, it becomes easy to suppress the vibration level of the vehicle constituent member below the upper limit line .
Furthermore, according to the invention described in claim 6, since the first and second dynamic dampers are set so that the vibration level of the vehicle component is suppressed to the upper limit line or less, the resonance of the vehicle component is performed. Occupant discomfort due to noise caused by vibration can be more reliably suppressed.

It is a side view showing the propeller shaft to which the dynamic damper for vehicles concerning a 1st embodiment was attached. It is a schematic diagram which shows the function of the dynamic damper attached to the propeller shaft shown in FIG. It is the sectional view on the AA line of FIG. 1 which shows the specific structure of a dynamic damper. It is sectional drawing which shows the specific example of the structure of a dynamic damper in the case of attaching a dynamic damper to a drive shaft. It is a graph which shows an example of the waveform of the vibration level with respect to the frequency of the propeller shaft to which the dynamic damper for vehicles concerning a 1st embodiment was attached. It is a graph which shows an example in case the peak of the resonance waveform by the side of a low frequency exceeds an upper limit about the waveform of the vibration level with respect to the frequency of the propeller shaft to which the 1st dynamic damper was attached. It is a side view which shows the propeller shaft with which the dynamic damper for vehicles which concerns on 2nd Embodiment was attached. It is a graph which shows an example of the waveform of the vibration level with respect to the frequency of the propeller shaft to which the dynamic damper for vehicles concerning a 2nd embodiment was attached. It is a graph which shows an example of the waveform of the vibration level with respect to the frequency of the propeller shaft to which the dynamic damper for vehicles concerning a 3rd embodiment was attached. It is a graph which shows the prior art example of the waveform of the vibration level with respect to the frequency of the propeller shaft to which the dynamic damper for vehicles was attached.

  Hereinafter, embodiments of the present invention will be described. In the following description, terms indicating directions such as “front”, “rear”, “front / rear” and the like refer to directions when the traveling direction of the vehicle is “front”, unless otherwise specified. Shall point to.

[First Embodiment]
FIG. 1 is a side view showing a propeller shaft 6 to which a vehicle dynamic damper 20 according to the first embodiment is attached.

  As shown in FIG. 1, the propeller shaft 6 extends in the vehicle front-rear direction in, for example, an FR type vehicle 1, and is connected to a power source 2 such as an engine, a transmission, or an electric motor via a joint member 4 at a front end thereof. At the rear end, it is drivingly connected to a rear wheel 10 as a driving wheel via a joint member 8.

  However, the vehicle 1 on which the propeller shaft 6 is mounted is not necessarily an FR type vehicle, and may be a four-wheel drive type vehicle, for example.

  The propeller shaft 6 may resonate with, for example, vertical vibration transmitted from the power source 2, and the resonance vibration of the propeller shaft 6 may cause noise. In order to solve this problem, in this embodiment, the dynamic damper 20 is attached to the propeller shaft 6 at a position corresponding to the antinode of the standing wave, for example.

  However, in the present invention, the dynamic damper 20 can be attached to an arbitrary position of the propeller shaft 6 as long as it can exhibit a vibration suppressing effect.

  FIG. 2 is a schematic diagram illustrating the function of the dynamic damper 20. As shown in FIG. 2, the dynamic damper 20 includes a mass body 22, a spring element 24 interposed between the mass body 22 and the propeller shaft 6, and a damping interposed between the mass body 22 and the propeller shaft 6. Element 26. The spring element 24 has a buffer function of absorbing an impact input to the propeller shaft 6 by vibrating the mass body 22 so as to cancel the vibration of the propeller shaft 6, and the damping element 26 is a mass body formed by the spring element 24. 22 has a damping function for attenuating 22 vibrations.

  The dynamic damper 20 has a specific set frequency Fb, and can effectively reduce the vibration level of the propeller shaft 6 at the set frequency Fb. Specifically, for example, as indicated by the symbol B in FIG. 5, the dynamic damper 20 generates a downward peak P2 in the waveform of the vibration level with respect to the frequency of the propeller shaft 6 at the set frequency Fb. Thereby, the resonance vibration of the propeller shaft 6 is effectively reduced at the set frequency Fb of the dynamic damper 20.

  The set frequency Fb of the dynamic damper 20 depends on various characteristics of the dynamic damper 20, specifically, for example, the mass M of the mass body 22 constituting the dynamic damper 20, the spring constant K of the spring element 24, or the damping element. The desired frequency can be set by adjusting the 26 attenuation coefficient C and the like.

  FIG. 3 is a cross-sectional view showing a specific structure of the dynamic damper 20 for constituting the mass body 22, the spring element 24, and the damping element 26 in the present embodiment.

  As shown in FIG. 3, the propeller shaft 6 is formed in a cylindrical shape, and a dynamic damper 20 is attached to the inside of the propeller shaft 6. The dynamic damper 20 includes, for example, a columnar weight 30 and an elastic member 32 that covers the outer peripheral surface of the weight 30. The elastic member 32 is made of, for example, rubber, and is fixed to the outer peripheral surface of the weight 30 by, for example, baking. The dynamic damper 20 is attached to the propeller shaft 6 by press-fitting the elastic member 32 into the propeller shaft 6 while compressing the elastic member 32 radially inward.

  In the structure of the dynamic damper 20, the weight 30 has a function as the mass body 22, and the elastic member 32 has both a function as the spring element 24 and a function as the damping element 26. Therefore, the set frequency Fb of the dynamic damper 20 can be adjusted by adjusting the material and hardness of the elastic member 32 or the mass of the weight 30.

  However, in the present invention, the specific structure of the dynamic damper 20 is not limited to the structure shown in FIG. 3, and may be a structure that can be fitted onto the propeller shaft 6, for example. In the present invention, the vehicle component whose vibration is suppressed by the dynamic damper is not limited to the propeller shaft 6, and for example, the dynamic damper is attached to the drive shaft in order to suppress the resonance vibration of the drive shaft. It may be.

  More specifically, for example, as shown in FIG. 4, a dynamic damper 120 is attached to the outer peripheral surface of the drive shaft 100, and the dynamic damper 120 is an annular weight attached to the outer side in the radial direction of the drive shaft 100. 130 and an elastic member 132 interposed between the weight 130 and the drive shaft 100 may be included. In this case, the weight 130 has a function as the mass body 22, and the elastic member 132 has both the function as the spring element 24 and the function as the damping element 26.

  A setting method of the dynamic damper 20 attached to the propeller shaft 6 will be described with reference to FIG.

  However, the setting method described below is similarly applied to the case where a dynamic damper having a structure different from the structure shown in FIG. 3 and a dynamic damper attached to a vehicle component other than the propeller shaft 6 are set. Can do.

  In FIG. 5, symbol A indicates a vibration level waveform with respect to frequency for the propeller shaft 6 to which the dynamic damper 20 is not attached, and symbol B indicates that the dynamic damper 20 set by the setting method according to the present embodiment is attached. A similar waveform for the propeller shaft 6 is shown, and the symbol T indicates the upper limit value of the vibration level of the propeller shaft 6.

  The upper limit value T of the vibration level is set to become lower as the frequency becomes lower, and forms a line inclined upward in the right direction in FIG. This is because the noise caused by the resonance vibration of the propeller shaft 6 is more harsh to the occupant as the frequency becomes lower for the reason described above.

  As indicated by reference symbol A, the vibration level of the propeller shaft 6 to which the dynamic damper 20 is not attached has a waveform in which a peak P1 is formed at the resonance frequency Fa of the propeller shaft 6, and the peak P1 exceeds the upper limit value T. Due to the resonance vibration of the propeller shaft 6, noise that is harsh to the occupant may occur.

  As indicated by reference numeral B, the vibration level of the propeller shaft 6 to which the dynamic damper 20 is attached to prevent the above noise is formed such that a downward peak P2 is formed at the set frequency Fb and the set frequency Fb is sandwiched between them. Resonant waveforms w1 and w2 are formed on the low frequency side and the high frequency side, respectively.

  In the present embodiment, the characteristics of the dynamic damper 20 are set so that the set frequency Fb of the dynamic damper 20 is set to a lower frequency side than the resonance frequency Fa of the propeller shaft 6. As a result, the downward peak P2 is formed on the lower frequency side than the resonance frequency Fa of the propeller shaft 6, so that the peak P3 of the resonance waveform w1 on the lower frequency side is reduced as compared with the conventional example shown in FIG. Then, the peak P4 of the resonance waveform w2 on the high frequency side becomes high. That is, according to the present embodiment, the peak of the resonance waveform w1 on the low frequency side can be made lower than the peak of the resonance waveform w2 on the high frequency side, so that the passenger can feel noise in a low frequency range. The vibration level can be reduced intensively.

  The amount by which the set frequency Fb of the dynamic damper 20 is shifted from the resonance frequency Fa of the propeller shaft 6 to the low frequency side is such that the peaks P3 and P4 of the resonance waveforms w1 and w2 on the low frequency side and the high frequency side are below the upper limit value T. Therefore, the vibration level of the propeller shaft 6 can be suppressed to the upper limit value T or less in the entire frequency range, and noise caused by the resonance vibration of the propeller shaft 6 is disturbed by the occupant. It can be reliably prevented to the extent that it is difficult to feel. Therefore, it is preferable that the set frequency Fb is set to be largely shifted from the resonance frequency Fa to the low frequency side as the inclination of the line of the upper limit value T shown in FIG. 5 is larger.

[Second Embodiment]
Subsequently, a second embodiment of the present invention will be described with reference to FIGS. Note that in the second embodiment, detailed description of the same configuration as in the first embodiment is omitted. Moreover, in FIGS. 6-8, the same code | symbol is attached | subjected to the component which has a function similar to 1st Embodiment.

  First, the problem of the setting method of the dynamic damper 20 according to the first embodiment will be described with reference to FIG. As shown in FIG. 6, according to the first embodiment, the peak P3 of the resonance waveform w1 on the low frequency side is reduced to some extent, but it is not necessarily reduced until the peak value is equal to or lower than the upper limit value T. In view of this point, in the second embodiment, the dynamic damper 20 is set as follows, so that more effective suppression of noise on the low frequency side is achieved.

  As shown in FIG. 7, in the second embodiment, in order to more effectively suppress the resonance vibration of the propeller shaft 6, the first dynamic damper 220 and the second dynamic damper 222 are provided on the propeller shaft 6. It is attached.

  In the second embodiment, as in the first embodiment, the vehicle constituent member whose vibration is suppressed by the dynamic dampers 220 and 222 may be a member other than the propeller shaft 6, such as the drive shaft 100, for example. The mounting positions of the first and second dynamic dampers 220 and 222 are not particularly limited as long as the vibration suppressing effect can be exhibited. Further, as in the first embodiment, the specific structure of the dynamic dampers 220 and 222 is not particularly limited, and may be, for example, the structure shown in FIG. 3 or the structure shown in FIG.

  A setting method of the first and second dynamic dampers 220 and 222 attached to the propeller shaft 6 will be described with reference to FIG.

  As in FIG. 5, in FIG. 8, the symbol A indicates the vibration level waveform with respect to the frequency for the propeller shaft 6 to which the dynamic dampers 220 and 222 are not attached, and the symbol B is set by the setting method according to the present embodiment. A similar waveform is shown for the propeller shaft 6 to which the first and second dynamic dampers 220 and 222 are attached, and a symbol T indicates an upper limit value of the vibration level of the propeller shaft 6.

  In the present embodiment, the same setting frequency Fb as that of the dynamic damper 20 according to the first embodiment is set in the first dynamic damper 220. That is, the characteristics of the first dynamic damper 220 are set such that the set frequency Fb of the first dynamic damper 220 is set to a lower frequency side than the resonance frequency Fa of the propeller shaft 6. As a result, as in the first embodiment, a downward peak P2 is formed at the set frequency Fb set on the lower frequency side than the resonance frequency Fa, and the resonance waveform w2 on the higher frequency side with the set frequency Fb interposed therebetween. Is formed. On the other hand, the waveform portion of the resonance waveform w1 (see FIG. 6) formed on the low frequency side across the set frequency Fb by attaching the first dynamic damper 220 is as follows. By setting the dynamic damper 220, the waveform is deformed as described later.

  The set frequency of the second dynamic damper 222 is equal to the frequency Fc (see FIG. 6) of the peak P3 of the resonance waveform w1 in order to reduce the maximum value of the waveform portion of the resonance waveform w1 on the low frequency side. Is set.

  As a result, as shown in FIG. 8, a downward peak P5 is formed at the set frequency Fc of the second dynamic damper 222, and the first and second frequencies are placed on the low frequency side and the high frequency side across the set frequency Fc. Resonance waveforms w3 and w4 having a peak P6 smaller than the peak P3 (see FIG. 6) of the resonance waveform w1 on the low frequency side formed by attaching the dynamic damper 220. Therefore, since the maximum value of the vibration level is further reduced in the low frequency range, it is possible to more effectively reduce the noise caused by the resonance vibration of the propeller shaft 6.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. Note that in the third embodiment, detailed description of the same configurations as those of the first or second embodiment will be omitted. In FIG. 9, components having the same functions as those in the first or second embodiment are denoted by the same reference numerals.

  In the third embodiment, as in the second embodiment, the first and second dynamic dampers 220 and 222 are attached to the propeller shaft 6. Further, the set frequency Fb of the first dynamic damper 220 is set in the same manner as in the second embodiment.

  Also in the third embodiment, as in the first and second embodiments, the vehicle constituent member whose vibration is suppressed by the dynamic dampers 220 and 222 is a member other than the propeller shaft 6, such as the drive shaft 100, for example. The mounting positions of the first and second dynamic dampers 220 and 222 are not particularly limited as long as the vibration suppressing effect can be exhibited. Further, as in the first and second embodiments, the specific structure of the dynamic dampers 220 and 222 is not particularly limited. For example, the structure shown in FIG. 3 or the structure shown in FIG. 4 may be used. .

  On the other hand, the set frequency Fd of the second dynamic damper 222 is different from that of the second embodiment, and the first dynamic damper 222 is attached to the propeller shaft 6 to sandwich the set frequency Fb of the first dynamic damper 222. It is set on the low frequency side compared to the frequency Fc (see FIG. 6) of the peak P3 of the resonance waveform w1 formed on the low frequency side.

  As a result, as in the second embodiment, a downward peak P7 is formed at the set frequency Fd of the second dynamic damper 222, and the second peak is set on the low frequency side and the high frequency side across the set frequency Fd. Resonant waveforms w5 and w6 having peaks P8 and P9 smaller than the peak P3 (see FIG. 6) of the resonance waveform w1 on the low frequency side formed by attaching one dynamic damper 220 are formed. Therefore, since the maximum value of the vibration level is further reduced in the low frequency range, it is possible to more effectively reduce the noise caused by the resonance vibration of the propeller shaft 6.

  Moreover, in the present embodiment, unlike the second embodiment, the setting frequency Fd of the second dynamic damper 222 is lower than the frequency Fc (see FIG. 6) of the peak P3 of the resonance waveform w1 on the low frequency side. Therefore, the peak P8 of the resonance waveform w5 on the low frequency side across the set frequency Fd is lower than the peak P9 of the resonance waveform w6 on the high frequency side across the setting frequency Fd. As a result, the vibration level in the low frequency range can be more significantly suppressed, and the noise reduction effect can be further enhanced.

  The amount of shifting the set frequency Fd of the second dynamic damper 222 from the frequency Fc (see FIG. 6) of the peak P3 of the resonance waveform w1 on the low frequency side to the low frequency side is low and high on both sides of the set frequency Fd. It is preferable to set an amount such that the peaks P8 and P9 of the resonance waveforms w5 and w6 on the frequency side are less than or equal to the upper limit value T, whereby the vibration level of the propeller shaft 6 is less than or equal to the upper limit value T in all frequency ranges. It is possible to suppress the noise caused by the resonance vibration of the propeller shaft 6 to the extent that it is difficult for the occupant to feel annoying. Therefore, it is preferable that the set frequency Fd is set so as to be largely shifted from the frequency Fc to the lower frequency side as the inclination of the line of the upper limit value T shown in FIG. 9 is larger.

  While the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  As described above, according to the present invention, when a dynamic damper is attached to a vehicle component, it is possible to effectively reduce noise caused by resonance vibration of the vehicle component so that it is difficult for an occupant to feel it. Therefore, there is a possibility of being suitably used in the field of the manufacturing industry of a vehicle provided with a vehicle constituent member capable of suppressing resonance vibration by a dynamic damper.

1: Vehicle, 2: Power source, 6: Propeller shaft (vehicle component), 10: Drive wheel, 20, 120, 220, 222: Dynamic damper, 100: Drive shaft (vehicle component), Fa: Propeller shaft Resonance frequency, Fb, Fd: set frequency of the dynamic damper.

Claims (6)

To suppress the resonance vibration at the resonance frequency of the I Ri arising vehicle component to the vibration from the vibration source by being attached to said vehicle component, the vibration level for the frequency of the vibration, a low frequency side and high frequency On the other hand, there is provided a vehicle dynamic damper setting method for forming a resonance waveform having a peak lower than a vibration level peak at the resonance frequency ,
The upper line of the vibration level for the frequency of vibration of the vehicle structure member, and the low frequency side is lower than the high frequency side, the peak of the vibration level at the resonance frequency of the vehicle component when not provided with the dynamic damper Upper limit line setting process to set to be lower than ,
A dynamic damper setting step for setting the dynamic damper so that a vibration level of a peak of the resonance waveform on the low frequency side and the high frequency side in the vehicle constituent member is equal to or lower than the upper limit line ;
A method for setting a dynamic damper for a vehicle, comprising: In the dynamic damper setting step, the dynamic damper is set so that the vibration level at the peak of the resonance waveform on the low frequency side is lower than the vibration level at the peak of the resonance waveform on the high frequency side. The method for setting a dynamic damper for a vehicle according to claim 1, wherein: When the first and second dynamic dampers are attached to the vehicle constituent member in order to suppress the vibration of the vehicle constituent member that resonates with the vibration from the vibration source, the first and second dynamic dampers are set. A dynamic damper setting method,
Setting the characteristics of the first dynamic damper so that the set frequency of the first dynamic damper is set to be lower than the resonance frequency of the vehicle component;
The setting frequency of the second dynamic damper is set to the peak frequency of the resonance waveform formed on the low frequency side with the first dynamic damper being sandwiched by attaching the first dynamic damper to the vehicle component. A method for setting a dynamic damper for a vehicle, wherein the characteristic of the second dynamic damper is set so as to be equal to each other or set to a lower frequency side. To suppress the resonance vibration at the resonance frequency of the I Ri arising vehicle component to the vibration from the vibration source by being attached to said vehicle component, the vibration level for the frequency of the vibration, a low frequency side and high frequency On the other hand, there is provided a vehicle dynamic damper setting method for forming a resonance waveform having a peak lower than a vibration level peak at the resonance frequency ,
The upper line of the vibration level for the frequency of vibration of the vehicle structure member, and the upper-limit line setting step of setting as the low frequency side becomes lower than the high frequency side,
The frequency of the downward peak occurring between the low frequency side of the peak and the high frequency side of the peak in the resonance waveform of the vehicle component in a state with the dynamic damper, the vehicle structure when not provided with the dynamic damper than the resonant frequency of the vibration level of the member becomes the maximum is set to the low frequency side, and the vibration level of the peak of the low frequency side and a resonant waveform of the high-frequency side in the vehicle component is less than the upper limit line A dynamic damper setting step for setting the dynamic damper,
A method for setting a dynamic damper for a vehicle, comprising: 5. The vehicle dynamic according to claim 4, wherein the dynamic damper setting step increases a shift amount of the frequency of the downward peak with respect to the resonance frequency to a low frequency side as the inclination of the upper limit line is larger. How to set the damper. A method for setting a dynamic damper for a vehicle attached to a vehicle component in order to suppress vibration of the vehicle component that causes resonance vibration at a predetermined frequency due to vibration from a vibration source,
The upper limit value of the vibration level for the predetermined frequency in the vehicle component member is set so as to decrease as the vibration frequency decreases,
The setting frequency of the dynamic damper that forms the minimum value of the vibration level of the vehicle component in the state provided with the dynamic damper is set to a frequency at which the vibration level of the vehicle component is maximized when the dynamic damper is not provided. Is also set to the low frequency side,
The set frequency of the dynamic damper is set to a frequency such that the vibration level of the vehicle component is less than or equal to the upper limit value,
The dynamic damper includes a first dynamic damper and a second dynamic damper,
The set frequency in the first dynamic damper and the second dynamic damper is set to a lower frequency side than the frequency at which the vibration level of the vehicle constituent member is maximum when the dynamic damper is not provided; and
Wherein the low frequency side first dynamic damper and the set frequency of the second dynamic damper, the vehicle vibration level of the component members characterized in that it is set to a frequency equal to or less than the upper limit vehicle dual dynamic damper Setting method.

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