JP2016112952A - Cab panel vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce vibrations of a cab panel while suppressing an increase in a number of components.SOLUTION: A bracket 11 formed to have a hat-shaped cross section is provided, and a flange portion 11a of the bracket 11 is fixed to a roof panel 2a. A rubber member 12 is disposed across a web portion 11b of the bracket 11, and a room lamp 13 is suspended from the web portion 11b through the rubber member 12. A spring-mass system is composed of the rubber member 12 and the room lamp 13, and functions as a dynamic damper for reducing vibrations of the roof panel 2a.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cab panel vibration damping device that reduces vibration of a cab panel that causes a noise in a cab in a vehicle.

  2. Description of the Related Art Conventionally, various techniques for reducing vibrations of a cab panel forming the cab have been proposed in order to reduce hum generated in a cab of a vehicle. For example, Patent Document 1 describes a technique in which a dynamic damper is provided on a back panel of a cab to reduce vibration of the back panel. In the technique described in Patent Document 1, the dynamic damper is configured by an elastic plate material and masses fixed to both ends of the elastic plate material.

JP-A-10-278852

  By the way, in order to reduce the noise generated in the cab of the vehicle, it is also important to reduce the vibration of the roof panel of the cab. However, for example, if a dynamic damper composed of an elastic plate material and a mass described in Patent Document 1 is added to the roof panel, the number of parts increases.

  The present case has been devised in view of the problems as described above, and provides a cab panel vibration damping device capable of reducing the vibration of the cab panel while suppressing an increase in the number of parts. One of the purposes.

  The cab panel vibration damping device disclosed here reduces vibration of a cab panel of a vehicle. The cab panel vibration damping device is formed in a hat-shaped cross section, and is suspended via a bracket in which a flange portion is fixed to a ceiling portion of the cab panel, and a rubber member that is disposed with a web portion of the bracket interposed therebetween. A room lamp.

  According to the disclosed cab panel vibration damping device, since the room lamp is suspended from the bracket via the rubber member, the room lamp and the rubber member can be configured by using the room lamp. Therefore, it is possible to reduce the vibration of the cab panel while suppressing an increase in the number of parts, and it is possible to reduce the humming noise in the cab.

It is a longitudinal cross-sectional view (AA arrow sectional drawing of FIG. 2) of the principal part of the cab panel to which the cab panel damping device concerning this embodiment was applied. It is a perspective view of the cab panel of FIG. 1, and a virtual line shows the vibration mode in case the cab panel vibration damping device which concerns on this embodiment is not applied.

With reference to the drawings, a cab panel vibration damping device according to the present embodiment will be described. The embodiment described below is merely an example, and there is no intention of excluding various modifications and technical applications that are not explicitly described in the following embodiment.
In the drawings, arrow F indicates the front of the vehicle, arrow UP indicates the upper side of the vehicle, and arrow R indicates the right side of the vehicle when the vehicle front is viewed from the rear of the vehicle.

[1. Constitution]
The cab panel damping device according to the present embodiment is provided on the cab panel 2 of the vehicle shown in FIG. 2 and reduces the vibration of the cab panel 2. The cab panel 2 forms the cab of the vehicle, and is formed, for example, by pressing and welding a plurality of panel members. The cab panel 2 has a roof panel 2a at its upper end. The roof panel 2a forms a ceiling portion of the cab panel 2, and extends along the vehicle length direction and the vehicle width direction.

  2 indicates the vibration mode of the cab panel 2 when the cab panel vibration control device according to the present embodiment is not provided in the cab panel 2. That is, in the cab panel 2 in the case where the cab panel damping device according to the present embodiment is not provided, a vibration peak (maximum amplitude) at the time of resonance occurs in the portion B of the roof panel 2a.

  As shown in FIG. 1, a head lining 3 is provided below the roof panel 2a (inside the cab). The head lining 3 is an interior material for enhancing the aesthetic appearance of the passenger compartment provided in the cab, extends substantially parallel to the roof panel 2a, and is disposed with a gap between the roof panel 2a. The headlining 3 has a hole 3a in which a room lamp 13 that illuminates the vehicle interior is attached to a portion B in FIG.

  The cab panel vibration damping device 1 includes a bracket 11 fixed to the roof panel 2 a and a room lamp 13 suspended from the bracket 11 via a rubber member 12 disposed on the bracket 11. The rubber member 12 and the room lamp 13 constitute a spring-mass system. That is, in the cab panel damping device 1, a dynamic damper is configured by a spring-mass system in which the rubber member 12 functions as a spring and the room lamp 13 functions as a mass.

  The spring-mass system (rubber member 12 and room lamp 13) is attached via a bracket 11 to a position (B portion in FIG. 2) where the amplitude of the resonance point in the roof panel 2a is maximized. The resonance frequency (natural frequency) of the spring-mass system is set so as to coincide with the resonance frequency of the roof panel 2a. That is, the spring constant of the rubber member 12 and the mass of the room lamp 13 are set according to the resonance frequency of the roof panel 2a. When the mass of the room lamp 13 cannot be changed, for example, when an existing room lamp 13 is used, the resonance frequency of the spring-mass system is adjusted by tuning the spring constant of the rubber member 12. Can be adjusted.

  The bracket 11 is for attaching the room lamp 13 to the roof panel 2a, and is formed into a cross-sectional hat shape by, for example, a steel plate. The bracket 11 includes a pair of flange portions 11a and 11a, and a planar web portion 11b provided between the pair of flange portions 11a and 11a via a standing wall portion. The flange portion 11a is fixed to the lower surface (surface on the vehicle interior side) of the roof panel 2a by, for example, welding. A room lamp 13 is attached to the web portion 11b via a rubber member 12.

  The rubber member 12 is formed of a member having elasticity, and elastically connects the web portion 11b of the bracket 11 and the room lamp 13. The rubber member 12 is disposed in a pair above and below the web portion 11 b of the bracket 11, and is fixed to the web portion 11 b together with the room lamp 13 by the bolt 4. In other words, the pair of upper and lower rubber members 12 are arranged with the web portion 11 b of the bracket 11 interposed therebetween, and are fixed to the web portion 11 b with one bolt 4. In the present embodiment, a pair of upper and lower rubber members 12 are fixed to four locations in the web portion 11b.

  For example, the rubber member 12 may be provided at a position corresponding to each corner of the room lamp 13 or may be formed in a donut shape and disposed concentrically with the room lamp 13. That is, the rubber member 12 only needs to be able to stably and elastically connect the bracket 11 and the room lamp 13, and the specific shape and number thereof are not particularly limited.

  The room lamp 13 is disposed so as to block the hole 3 a of the headlining 3 from below, and the upper surface of the room lamp 13 is fixed in contact with the rubber member 12. Since the shape of the room lamp 13 is not particularly limited, for example, an existing room lamp can be used as the room lamp 13.

[2. effect]
In the cab panel vibration damping device 1, the room lamp 13 is suspended from the bracket 11 via the rubber member 12. Therefore, a dynamic damper can be constituted by the room lamp 13 and the rubber member 12 using the room lamp 13. That is, since the room lamp 13 is applied as a mass in the spring-mass system of the dynamic damper, instead of adding a new heavy object, vibration of the cab panel 2 can be reduced while suppressing an increase in the number of parts. it can. Therefore, it is possible to reduce the muffled sound in the cab caused by the vibration of the cab panel 2.

  Further, in the cab panel vibration damping device 1, the rubber member 12 and the room lamp 13 constitute a spring-mass system, and the resonance frequency of the spring-mass system is set to coincide with the resonance frequency of the roof panel 2a. . Thereby, the rubber member 12 and the room lamp 13 function as a dynamic damper, and the vibration of the roof panel 2a can be reduced. That is, according to the cab panel vibration damping device 1, since the maximum amplitude of the roof panel 2a can be reduced, the vibration of the entire cab panel 2 can be reduced.

Moreover, according to the cab panel damping device 1, since the room lamp 13 and the rubber member 12 are attached to the roof panel 2a via the bracket 11, the vibration of the roof panel 2a can be effectively reduced. The roof panel 2a has a simple structure as compared with other panel members constituting the cab panel 2 and has a low resonance frequency. Therefore, the roof panel 2a easily resonates with engine vibration at the time of low rotation of the vehicle engine. In particular, it is a part that requires damping. According to the cab panel vibration damping device 1, since the resonance vibration of the roof panel 2a can be effectively reduced as described above, it is possible to effectively reduce the muffled noise in the cab.
In the cab panel vibration damping device 1, the rubber member 12 is disposed with the web portion 11 b of the bracket 11 interposed therebetween. Therefore, the room lamp 13 can be stably suspended.

[3. Modified example]
Regardless of the embodiment described above, various modifications can be made without departing from the spirit of the present embodiment. Each structure of this embodiment can be selected as needed, or may be combined appropriately.

  The shapes of the roof panel 2a and the bracket 11 shown in the present embodiment are examples and can be changed. For example, a bead extending in the vehicle length direction may be formed on the roof panel 2a. Moreover, the bracket 11 should just be ensured the rigidity for supporting the room lamp 13 by forming in a cross-sectional hat shape, and the material, the fixing method to the roof panel 2a, etc. are not specifically limited. Further, the positions of the rubber member 12 and the room lamp 13 are not limited to those shown in the drawings, and are set to appropriate positions according to the resonance point of the roof panel 2a.

1 Cab panel damping device 2 Cab panel 2a Roof panel (ceiling)
11 Bracket 11a Flange part 11b Web part 12 Rubber member 13 Room lamp

Claims (1)

In a cab panel damping device that reduces vibration of a cab panel of a vehicle,
A bracket formed in a cross-sectional hat shape, and a flange portion fixed to the ceiling portion of the cab panel;
A room lamp suspended via a rubber member disposed across the web portion of the bracket;
A cab panel vibration damping device characterized by comprising:

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