JP5251368B2 - Body superstructure - Google Patents

Description

  The present invention relates to an upper structure of a vehicle body in a vehicle, and more particularly to an upper structure of a vehicle body that is intended to reduce a booming noise in a vehicle interior.

2. Description of the Related Art Conventionally, a booming noise that impairs passenger comfort has been generated in a vehicle cabin. One of the causes of such a booming noise in the passenger compartment is the vibration of the window surface up and down (in the normal direction of the window).
By the way, in recent years, the air resistance of vehicles has been reduced for reasons such as improving fuel efficiency and ensuring high-speed stability. Along with this, since the inclination of the window (especially the front window) tends to increase, the area of the window increases, and the proportion of the outer shell area in the passenger compartment increases. Since such a window has a large area of a uniform material, it has a great influence on the noise of the vehicle interior, and it is becoming increasingly important to control the vibration of the window.

Therefore, conventionally, as shown in Patent Document 1, an example in which the muffled noise is reduced by improving the rigidity of the cowl panel at the front end of the vehicle interior, or as shown in Patent Documents 2 and 3, Focusing on vibration, there is an example in which the vibration of the roof is reduced by a configuration such as addition of a member or reinforcement.
JP 2007-137367 A JP 2007-168699 A JP 2004-168081 A

However, in the conventional structure shown in Patent Document 1 described above, since the rigidity of the cowl panel is only improved, the effect is local, and the vibration around the cowl panel and the dash panel is reduced. It is only to let you. In addition, in the conventional structures shown in Patent Documents 2 and 3, since members and reinforcements are added, the structure is complicated and the weight is increased. Have a problem. In addition, it is a measure limited to the roof portion, and is not a measure against the vibration of the window, which is one of the causes of the occurrence of a booming noise in the passenger compartment.
Although it is possible to suppress the vibration of the window by increasing the rigidity of each member and fixing it to the rigid, the rigidity of the parts can be increased by increasing the panel thickness, using high-strength steel sheets or adding reinforcements. Increasing the cost not only causes a high cost of the material and a decrease in workability, but also has a problem of causing a deterioration in fuel consumption due to an increase in weight of the roof portion. In addition, during the acceleration / deceleration of the vehicle, it is necessary to reinforce the base of the vehicle body in order to support the roof portion that has increased in weight, which causes a further decrease in productivity and deterioration of fuel consumption.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a vehicle body capable of reducing the noise of a vehicle interior with a simple structure without incurring an increase in cost or an increase in weight. It is to provide a superstructure.

In order to solve the above-described problems of the prior art, the present invention provides a cowl panel joined to a lower end of a front window, a front member joined to an upper end of the front window and a front end of the roof panel, a rear member that are joined to the rear end and the rear window of the front end, the upper structure of the vehicle body provided with a partition member is joined to the rear end of the rear window, the cowl panel, the front member of the roof panel, said rear member and the natural frequency of the partition member, the cowl panel, the front member, the rear member, and a high value in the order of the partition member, the cowl panel, the front member, the rear member and the natural frequency of the partition member to each other is Set differently The natural frequency of the cowl panel is higher than the natural frequency of the booming sound in the vehicle interior, the natural frequency of the front member is higher than the natural frequency of the booming sound in the vehicle interior, and the natural frequency of the rear member. Is set to be lower than the natural sound frequency of the booming sound in the vehicle interior, and none of the cowl panel, the front member, the rear member, or the partition member matches the natural vibration frequency of the vehicle interior noise. It is configured .

Further, in the present invention, a center member that connects the upper ends of the center pillars and is joined to the middle of the roof panel is provided, the cowl panel, the front member of the roof panel, the rear member, the center member, and the partition The natural frequency of the members is set to a higher value in the order of the cowl panel, the front member, the center member, the rear member, and the partition member .

In the present invention, the cowl panel has a closed cross-sectional shape when viewed from the side of the vehicle, and has a bulk structure standing wall at the center of the cowl panel in the vehicle width direction .
Further, in the present invention, the front member has a closed cross section, in the vehicle width direction center of the front member has a vertical wall of the bulk structure.

As described above, the upper structure of the vehicle body according to the present invention includes a cowl panel joined to the lower end of the front window, a front member joined to the upper end of the front window and the front end of the roof panel, and the rear end of the roof panel. A rear member joined to the front end of the rear window, and a partition member joined to the rear end of the rear window , the cowl panel, the front member of the roof panel, the rear member , and the partition. natural frequency of the member, the cowl panel, the front member, the rear member, and a high value in the order of the partition member, the cowl panel, the front member, the rear member and the natural frequency of the partition members each other differ from each other Set to the Kaulpa The natural frequency of the front member is higher than the natural frequency of the booming sound in the passenger compartment, the natural frequency of the front member is higher than the natural frequency of the loud noise of the passenger compartment, and the natural frequency of the rear member is higher than the natural frequency of the passenger compartment. It is set to be lower than the natural sound frequency of the booming sound, and the cowl panel, the front member, the rear member, and the partition member are configured so as not to coincide with the natural frequency of the loud sound of the vehicle interior. Yes.
Such a superstructure of the vehicle body according to the present invention takes the following points into consideration. That is, it is known that when the natural frequency of the cowl panel and the member that supports the window matches the natural frequency of the acoustic mode in the passenger compartment, the vibration of the window surface increases and the muffled noise increases. This acoustic mode is designed to vibrate greatly toward the front and rear of the passenger compartment at the center in the front and rear direction of the passenger compartment. Is effective. Further, the cause of the booming noise is considered to be caused by engine vibration or steering vibration at the time of engine idling, so that the vibration in the front part of the passenger compartment tends to increase. Further, when the natural frequencies of the cowl panel and the member are the same, a plurality of cowl panels and members vibrate in synchronism at a specific frequency, so that there is a possibility that the booming noise increases. Therefore, the natural frequency of the members each other at both ends of the window or roof panel that are different.
In the upper structure of the vehicle body according to the present invention, none of the cowl panel, the roof panel front member, and the roof panel rear member match the natural vibration frequency of the vehicle interior, and the roof panel rear member. It is possible to reduce the rigidity of the vehicle interior, so that it is possible to efficiently reduce the muffled noise in the vehicle interior, without increasing the rigidity of the vehicle interior, to suppress the increase in the vehicle weight, without taking a complicated structure, The noise can be reduced.
Furthermore, in the superstructure of the vehicle body according to the present invention, when the partition member is provided, the partition member is farthest from the vibration source, and the area of the rear window is smaller than the area of the front window. It becomes possible to set low. As a result, it is possible to efficiently reduce the muffled noise in the passenger compartment without increasing the rigidity of the vehicle, to suppress the increase in the vehicle weight, and to take measures to reduce the muffled noise in the passenger compartment without taking a complicated structure. it can.

  Based on these considerations, in the superstructure of the vehicle body according to the present invention, the rigidity of the cowl panel portion at the front of the passenger compartment closer to the vibration source is maximized, and the rigidity is gradually lowered with the front member of the roof panel and the rear member of the roof panel. As a result, there is no need to uselessly improve the rigidity of the members and the like, and it is possible to efficiently reduce the noise of the vehicle interior. In addition, according to the superstructure of the present invention, it is possible to suppress an increase in the vehicle weight and to take a countermeasure against the booming noise in the vehicle interior without taking a complicated structure.

  Further, in the present invention, a center member that connects the upper ends of the center pillars and is joined to the middle of the roof panel is provided, and the natural frequency of the cowl panel, the front member of the roof panel, the rear member, and the center member is provided. Is set to a higher value in the order of the cowl panel, the front member, the center member, and the rear member. Therefore, in the upper structure of the vehicle body according to the present invention, when the center member of the roof panel is connected to the upper end of the center pillar, not only the natural vibration of the roof panel is reduced by the center member but also the entire interior of the vehicle interior. The acoustic mode will be improved. In this case, by setting the rigidity of the center member between the front member and the rear member, it is possible to efficiently reduce the muffled noise in the passenger compartment without increasing the rigidity, and to suppress the increase in the vehicle weight and to make the complicated Without taking the structure, it is possible to reduce the muffled noise in the passenger compartment.

  Further, in the present invention, the cowl panel has a closed cross-sectional shape when viewed from the lateral direction of the vehicle, and has a bulk structure standing wall at the center of the cowl panel in the vehicle width direction. That is, in the upper structure of the vehicle body according to the present invention, the cowl panel portion, which requires the most rigidity to reduce the vertical vibration of the window, has a closed cross section and a reinforcement (standing wall) in the center to form a bulk structure. . This is because, in order to reduce the vertical vibration of the window, it is effective to press the lower part of the window with the cowl panel part and particularly to improve the rigidity of the central part. With this configuration, it is possible to efficiently reduce the muffled noise in the passenger compartment.

  In the present invention, the front member has a closed cross-sectional shape, and has a bulk structure standing wall at the center in the vehicle width direction of the front member. That is, in the upper structure of the vehicle body according to the present invention, the roof panel front member that requires rigidity following the cowl panel portion to reduce the vertical vibration of the window has a closed cross section and a reinforcement (standing wall) in the center. To provide a bulk structure. This is because, in order to reduce the vertical vibration of the window, it is effective to press the lower part of the window with the cowl panel portion and the upper part of the window with the front member. In addition, improving the rigidity of the central part with the bulk structure not only reduces the vertical vibration of the front window, but also has the effect of suppressing the amplitude of the vibration mode of the roof. Sound can be reduced.

Hereinafter, an upper structure of a vehicle body according to the present invention will be described in detail based on an embodiment thereof with reference to the drawings.
FIG. 1 is a perspective view of an automobile to which a superstructure of a vehicle body according to an embodiment of the present invention is applied as viewed obliquely from the upper side, and FIG. 2 is a perspective view of a cowl panel and a front window located at the front of the vehicle body in FIG. 3 is an enlarged perspective view of the cowl panel in FIG. 2 with the cowl front panel removed, and FIG. 4 is a side view of the periphery of the roof panel of the automobile to which the upper structure of the above embodiment is applied.

  As shown in FIGS. 1 to 4, the upper structure of the automobile body in the embodiment of the present invention has a loop panel 3 that covers from the rear end (upper part) of the front window 1 to the front end (upper part) of the rear window 2. The loop panel 3 is provided over the entire region in the vehicle front-rear direction and the vehicle width direction. Further, front pillars 4 are provided along the vehicle longitudinal direction on both sides of the front window 1 in the vehicle width direction, and center pillars 5 are provided along the vehicle vertical direction on both sides of the loop panel 3 in the vehicle width direction. Yes. Side body panels 6 are provided on the left and right side surfaces of the front window 1, the loop panel 3, and the rear window 2, respectively.

A cowl panel 11 extending over substantially the entire length in the vehicle width direction is joined to the lower end of the front window 1 via an adhesive or the like. The cowl panel 11 is a dash panel 12 that partitions the engine room and the vehicle compartment. It is arrange | positioned above. The dash panel 12 is located behind a front strut portion (not shown).
As shown in FIGS. 2 and 3, the cowl panel 11 includes three parts, a cowl top panel 13, a cowl upper panel 14, and a cowl lower panel 15, which are arranged in a substantially U-shaped cross section that opens to the front of the vehicle. The opening in front of the vehicle is closed by a cowl front panel (reinforcement) 16. Accordingly, the cowl panel 11 has a closed cross-sectional shape when viewed from the lateral direction of the vehicle and has a bulk structure, and a reinforcement member 17 forming a standing wall of the bulk structure is provided at the center in the vehicle width direction.

On the other hand, a front member 31 is joined to the upper end of the front window 1 and the front end of the roof panel 3 below the roof panel 3 with an adhesive or the like. For this reason, the front member 31 is formed in a curved shape projecting forward of the vehicle corresponding to the upper end shape of the front window 1 and the front end shape of the roof panel 3, and extends over substantially the entire length in the vehicle width direction. Moreover, the front member 31 has a closed cross-sectional shape and has a bulk structure, and a reinforcement member (not shown) that forms a standing wall of the bulk structure is provided at the center in the vehicle width direction, like the cowl panel 11. Yes.
Further, a center member 32 that joins the upper end of the center pillar 5 is joined to the lower half of the roof panel 3 and at an intermediate position in the front-rear direction of the roof panel 3 located behind the front member 31 in the vehicle. For this reason, the center member 32 is formed in a straight line corresponding to the intermediate portion of the roof panel 3 and extends over substantially the entire length in the vehicle width direction. Note that both ends of the center member 32 in the vehicle width direction coincide with the joining positions of the upper part of the center pillar 5.

A rear member 33 is joined to the rear end of the roof panel 3 located below the roof panel 3 and behind the center member 32 in the vehicle. Therefore, the rear member 33 is formed in a curved shape protruding rearward of the vehicle corresponding to the rear end shape of the roof panel 3 and the front end shape of the rear window 2, and extends over substantially the entire length in the vehicle width direction.
Furthermore, the front end (upper part) of the rear window 2 is joined to the rear of the rear member 33 via an adhesive or the like. A partition member 34 is joined to the rear end (lower part) of the rear window 2 via an adhesive or the like. The partition member 34 is formed in a curved shape protruding rearward of the vehicle corresponding to the rear end shape of the rear window 2, and extends over substantially the entire length in the vehicle width direction.

Further, the natural frequencies of the cowl panel 11, the front member 31 of the roof panel 3, the center member 32, and the rear member 33 according to the embodiment of the present invention are higher in the order of the cowl panel 11, the front member 31, the center member 32, and the rear member 33. It is said. For example, the natural frequency of the highest cowl panel 11 is set to 85 Hz, and the natural frequency of the lowest rear member 33 is set to 45 Hz. The natural frequency of the partition member 34 is set to be lower than the natural frequency of the rear member 33. That is, the natural frequencies of the cowl panel 11, the front member 31, the center member 32, the rear member 33, and the partition member 34 are set to be different from each other so that a plurality of members do not vibrate in synchronism with a specific frequency. It has become. For this reason, the rigidity of the cowl panel 11 closest to the vibration source is made highest, and the rigidity of the partition member 34 farthest from the vibration source is made lowest.
In addition, the natural frequency of the cowl panel 11 is higher than the natural vibration frequency of the vehicle interior, the natural frequency of the front member 31 is higher than the natural vibration frequency of the vehicle interior, and the natural vibration of the rear member 33. The number is set to be lower than the natural frequency of the booming sound in the passenger compartment. As a result, the cowl panel 11, the front member 31, the center member 32, the rear member 33, and the partition member 34 are all configured so as not to coincide with the natural frequency of the booming sound in the passenger compartment.

  In the superstructure of the vehicle body according to the embodiment of the present invention, the natural vibrations of the cowl panel 11, the front member 31 of the roof panel 3, the center member 32 and the rear member 33, and the partition member 34 arranged from the front part of the vehicle body to the rear part of the vehicle body. The natural frequency of the cowl panel 11 is set to be higher than the natural sound of the booming sound in the vehicle interior, and the natural frequency of the front member 31 is set to the natural frequency of the noise of the vehicle interior. And the natural frequency of the rear member 33 is set so as to be lower than the natural frequency of the loud noise in the passenger compartment, so that it propagates from the engine or transmission to the passenger compartment via the vehicle body frame or the dash panel 11. Vibration from the front suspension frame to the front pillar 4 via the steering shaft Vibration sowing, it is possible to damp vibrations and to propagate into the passenger compartment from the front strut portion for receiving the front wheel load can be reduced efficiently cabin booming noise.

  In addition, in the superstructure of the vehicle body according to the embodiment of the present invention, the rigidity of the cowl panel 11 closest to the vibration source is maximized, and the rigidity is gradually lowered toward the front member 31, the center member 32, and the rear member 33 of the roof panel 3. Since the rigidity of the partition member 34 farthest from the vibration source is made the lowest, it is not necessary to use a useless rigidity improvement or a complicated structure, and it is possible to suppress the booming noise while suppressing an increase in vehicle weight and cost. It can be performed.

  While the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

It is the perspective view which looked at the motor vehicle to which the superstructure of the vehicle body concerning the embodiment of the present invention is applied from the slanting upper side. It is a perspective view which shows the cowl panel and front window which are located in the vehicle body front part of the motor vehicle in FIG. FIG. 3 is an enlarged perspective view showing the cowl panel in FIG. 2 with the cowl front panel removed. It is a side view of the periphery of the roof panel of the motor vehicle to which the superstructure of the embodiment is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front window 2 Rear window 3 Roof panel 4 Front pillar 5 Center pillar 11 Cowl panel 13 Cowl top panel 14 Cowl upper panel 15 Cowl lower panel 16 Cowl front panel 17 Reinforce member (standing wall)
31 Front member 32 Center member 33 Rear member 34 Partition member

Claims (4)

A cowl panel joined to the lower end of the front window, a front member joined to the upper end of the front window and the front end of the roof panel, a rear member joined to the rear end of the roof panel and the front end of the rear window, and the rear In the superstructure of the vehicle body provided with a partition member joined to the rear end of the window ,
The cowl panel, the front member of the roof panel, said rear member and the natural frequency of the partition member, the cowl panel, the front member, the rear member, and a high value in the order of the partition member, the cowl panel, the front The natural frequency of the member, the rear member, and the partition member is set to be different from each other, the natural frequency of the cowl panel is higher than the natural frequency of the booming sound in the passenger compartment, and the natural frequency of the front member is It is set so as to be higher than the natural vibration frequency of the booming sound in the vehicle interior and lower than the natural vibration frequency of the rear member of the vehicle interior, and the cowl panel, the front member, the rear member, and the None of the partition members Vehicle superstructure, characterized in that it is configured not to match the interior of the muffled sound natural frequency. A center member that connects the upper ends of the center pillars and is joined to the middle of the roof panel is provided, and the natural frequency of the cowl panel, the front member of the roof panel, the rear member, the center member, and the partition member is The upper structure of the vehicle body according to claim 1, wherein the cowl panel, the front member, the center member, the rear member, and the partition member have higher values in this order . 3. The vehicle body according to claim 1 , wherein the cowl panel has a closed cross-sectional shape when viewed from the lateral direction of the vehicle, and has a bulk structure standing wall at a center of the cowl panel in the vehicle width direction. Superstructure. The upper structure of a vehicle body according to any one of claims 1 to 3, wherein the front member has a closed cross-sectional shape, and has a bulk structure standing wall at the center in the vehicle width direction of the front member. .

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