JPH078168U - Undercover device for vehicle - Google Patents

Abstract

(57) [Summary] [Purpose] In an undercover device that covers the lower surface of an engine room and a mission room of a vehicle, outside noise can be effectively reduced without increasing the sealing degree of the undercover. [Structure] At least outer wall surfaces of the undercovers 6 and 11 are formed of sound absorbing materials 6b and 11b.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vehicle undercover device.

[0002]

[Prior art]

 An undercover that covers the underside of the engine room and mission room is used as one of the measures against vehicle noise. The under-cover is formed of a laminated shielding plate including a sound-absorbing material on the inner surface side, and is roughly divided into the engine side and the transmission side and attached to the chassis frame through appropriate gaps.

As an undercover structure for the engine room, a shield plate is attached between the engine oil pan and the chassis frame, and a bellows part that allows the shield plate to vibrate relative to the chassis frame side on the oil pan side. It has been proposed (Japanese Utility Model Publication No. 59-30776).

[0004]

[Problems to be solved by the device]

 By the way, the noise leaking downward from the gap of the undercover hits the road surface and is reflected to the cover, so there is a tendency to worsen the noise outside the vehicle (radiated sound from the underfloor to the left and right sides of the vehicle). If the gap of the under cover is reduced (enhancement of the cover is increased), there will be a problem that cooling performance will deteriorate.

An object of the present invention is to provide an undercover device that can effectively reduce vehicle exterior noise without increasing the degree of sealing of the cover.

[0006]

[Means for Solving the Problems]

 Therefore, in the under cover device that covers the lower surfaces of the engine room and the mission room of the vehicle, at least the outer wall surface of the under cover is formed of a sound absorbing material.

[0007]

[Action]

 The noise leaking downward from the gap of the under cover hits the road surface and is reflected to the cover, but the sound energy (noise level) reflected from the road surface by the sound absorbing material is attenuated on the outer wall surface of the cover.

[0008]

【Example】

 1 and 2 show an example of application to a truck. As a shielding plate surrounding an engine 3 mounted on a chassis frame 2 below the cab 1, a side cover 4 on the cab 1 side and a side cover 5 on the frame 2 side are provided. And an under cover 6 is attached, and an engine room 7 is formed by these covers 4 to 6. A sound absorbing material is attached to the floor panel 8 of the cab 1.

The engine room 7 is opened toward a front grill (which has an outside air intake) of the cab 1 via a radiator 9 (mounted on the chassis frame 2) located on the front surface thereof. An under cover 11 as a shielding plate surrounding a transmission (mounted on the chassis frame 2) behind the engine 3 is attached to the chassis frame 2 to form a mission room 12 following the engine room 7.

In this case, as the undercovers 6 and 11, sound absorbing materials 6b and 11b formed of a porous thin plate are attached to the outer wall surfaces of the same shielding plates 6a and 11a as in the conventional case. It should be noted that between the undercovers 6 and 11, appropriate clearances 14a and 14b are formed before and after sandwiching these connecting portions 13 as through holes for cooling air necessary for ensuring good cooling performance.

With such a configuration, the noise mainly leaking from the gaps 14a and 14b below the under covers 6 and 11 hits the road surface and is reflected by the covers 6 and 11 as shown by an arrow A, but the shielding plates 6a and 6b The sound absorbing materials 6b and 11b on the outer wall surface of 11a effectively reduce the sound energy reflected from the road surface, so that the gaps 14a and 14b of the undercovers 6 and 11 are reduced (enhancing the sealing degree of the covers 6 and 11). The noise level radiated from the underfloor of the vehicle to the left and right can be significantly reduced.

In order to enhance the effect of reducing the noise outside the vehicle caused by the sound absorbing materials 6b and 11b, the under covers 6 and 11 have the covers 6 and 11 (in this case, the under cover 11 of the engine 3 is removed) as shown in FIGS. It is desirable to form it in a cross-sectional shape (represented by a representative example) (such as a concavo-convex shape that is continuous in a corrugated shape or a multi-protrusion shape that is arranged at regular intervals) that positively increases the outer area. Further, if there is no problem in strength, the undercovers 6 and 11 may be integrally formed with the sound absorbing materials 6b and 11b.

[0013]

[Effect of device]

 In short, according to the present invention, in the undercover device that covers the engine room of the vehicle and the lower surface of the mission room, at least the outer wall surface of the undercover is made of the sound absorbing material. The effect is that noise can be effectively reduced.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a vehicle showing an embodiment of the present invention.

FIG. 2 is a sectional view of an engine room of the same.

FIG. 3 is a partial cross-sectional view of an engine room showing a desirable shape of an undercover.

FIG. 4 is a sectional view of the under cover.

[Description of symbols] 1 cab 2 chassis frame 3 engine 6 engine undercover 6a undercover shielding plate 6b undercover sound absorbing material 7 engine room 11 transmission undercover 11a undercover shielding plate 11b undercover sound absorbing material 12 Mission room 14a, 14b Gap

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shogo Nishikawa Ichichome, Ichichome, Ageo City, Saitama Prefecture Nissan Diesel Industry Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. An undercover device for a vehicle, which covers lower surfaces of an engine room and a mission room of the vehicle, wherein at least an outer wall surface of the undercover is made of a sound absorbing material.