Abstract:
A mounting arrangement for accepting a pipe through a boundary in a vehicle includes a dash defining a boundary between an engine compartment and a passenger compartment. A dash mat is disposed adjacent to the dash. A pipe extends through the dash between the engine compartment and the passenger compartment. A first mounting plate is positioned in the passenger compartment and accepts the pipe through a passage therein. A noise abating material is disposed between the dash and the mounting plate. The noise abating material contacts an outer circumferential surface of the pipe and overlaps a portion of the dash mat in an assembled position.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a heater pipe assembly in cooperation with a vehicle dash, and more specifically to a mounting plate assembly cooperating with noise abating material to reduce dash pass through noise levels.  
       BACKGROUND OF THE INVENTION  
       [0002]     A vehicle HVAC system typically includes a heater core positioned in an engine compartment on an opposite side of a firewall or dash from the passenger. In a conventional configuration, a pair of heater pipes or tubes extend from the heater core and an HVAC case through a passage in the dash to mate with appropriate delivery hardware in the passenger compartment. The pipes usually comprise stainless steel, plastic or rubber.  
         [0003]     A seal is generally provided in the heater pipe assembly between the heater pipes and the dash. The seal is typically designed to prevent water intrusion from the engine compartment to the passenger compartment. The seal generally is not independently held to the dash. During assembly, proper seal orientation relies on fore/aft positioning of the HVAC case with respect to the dash.  
         [0004]     While conventional seal configurations for a dash mounted HVAC unit provide an adequate seal between the engine compartment and the passenger compartment for water intrusion purposes, they offer minimal noise reduction capability.  
       SUMMARY OF THE INVENTION  
       [0005]     A mounting arrangement for accepting a pipe through a boundary in a vehicle includes a dash defining a boundary between an engine compartment and a passenger compartment. A dash mat is disposed adjacent to the dash. A pipe extends through the dash between the engine compartment and the passenger compartment. A first mounting plate is positioned in the passenger compartment and accepts the pipe through a passage therein. A noise abating material is disposed between the dash and the mounting plate. The noise abating material contacts an outer circumferential surface of the pipe and overlaps a portion of the dash mat in an assembled position.  
         [0006]     In other features, the passage includes a clearance greater than the outer circumferential surface of the pipe. The pipe extends through the passage without contacting the first mounting plate in the assembled position. A second mounting plate is positioned in the engine compartment and accepts the pipe through a passage therein, the passage having a clearance greater than the outer circumferential surface of the pipe. The pipe extends through the passage without contacting the second mounting plate in the assembled position. A noise abating material is disposed between the dash and the second mounting plate. The noise abating material contacts the outer circumferential surface of the pipe is the assembled position.  
         [0007]     A mounting arrangement for accepting heater pipes through a vehicle dash includes a dash defining a boundary between an engine compartment and a passenger compartment. The dash includes an opening incorporated in a planar portion for accepting the heater pipes. A step portion extends at an angle from the planar portion. A flange extends from the step portion and is laterally offset toward the passenger compartment. A dash mat contacts the planar portion, the step portion and the flange portion. A first mounting plate contacts the flange of the dash. A noise abating material is disposed between the dash and the first mounting plate. The noise abating material contacts an outer circumferential surface of the heater pipes and the step portion of the dash. The dash mat and the first noise abating material overlap at the step portion.  
         [0008]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0010]      FIG. 1  is a perspective view of the heater pipe assembly shown in an installed position;  
         [0011]      FIG. 2  is an exploded view of the heater pipe assembly;  
         [0012]      FIG. 3  is a cross sectional view of the heater pipe assembly taken along line  3 - 3  of  FIG. 1 ; and  
         [0013]      FIG. 4  is a flowchart illustrating steps for assembling the heater pipe assembly. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0015]     With initial reference to  FIGS. 1 and 2 , a heater pipe assembly according to the present invention is illustrated and generally identified at reference  10 . The heater pipe assembly  10  is shown in an assembled position in  FIG. 1  operably coupled to a vehicle firewall or dash  14 . The vehicle dash  14  defines a boundary between an engine compartment  18  and a passenger compartment  20 . The heater pipe assembly  10  generally includes a first mounting plate  24  disposed in the passenger compartment  20  and a second mounting plate  26  disposed in the engine compartment  18 . The first and second mounting plate  24 ,  26  cooperate to receive heater pipes  30  through passages  32  incorporated therein in the assembled position. A fastener or stud  36  extends from the first mounting plate  24  and is received by a nut  38  on an outboard surface  40  of the second mounting plate  26  for capturing the assembly  10  in the assembled position. It is appreciated that other fastening configurations may be employed between the first mounting plate  24  and the second mounting plate  26 .  
         [0016]     With specific reference to  FIG. 2 , the heater pipe assembly  10  will be described in greater detail. A first noise abating material  42  is disposed between the first mounting plate  24  and the dash  14 . A second noise abating material  44  is disposed between the second mounting plate  26  and the dash  14 . The first and second noise abating material  42 ,  44  preferably comprise a compliant material such as foam. As will be described, the first and second noise abating material  42 ,  44  contact respective outer circumferential surfaces of the pipes  30  to reduce noise passthrough from the engine compartment  18  to the passenger compartment  20 .  
         [0017]     With reference now to  FIGS. 1-3 , the first mounting plate  24  includes a planar portion  48  having step portions  50  on opposite sides extending toward the passenger compartment  20 . The step portions  50  lead into respective flange portions  52 . The flange portions  52  preferably extend parallel to the planar portion  48 . A pair of passages  56  are formed in the first mounting plate  24  to accept the pipes  30 . The passages  56  have a diameter greater than the pipes  30  to allow a gap A ( FIG. 3 ) between the pipes  30  and the first mounting plate  24  in the assembled position. The gap A precludes vibration between the pipes  30  and the first mounting plate  24  which diminishes noise passthrough into the passenger compartment  20 . The stud  36  is offset between the passages  56  and includes a threaded portion  58  on a distal portion for mating with the nut  38 .  
         [0018]     The dash  14  will now be described in greater detail. The dash  14  generally includes a planar portion  60  having an opening  62  incorporated therein. Although opening  62  is represented in the drawings as a single oval, other configurations are contemplated such as three distinct passages as described with respect to the first and second noise abating material  42  and  44 . Step portions  64  extend on opposite sides of the opening  62  toward the passenger compartment  20 . As most clearly shown in  FIG. 3 , the step portions  64  extend at an angle Φ with respect to the planar portion  60  of the dash  14 . The angle Φ creates an overlap relationship (distance B) between the dash mat  70  and the first noise abating material  42 . The overlap B inhibits noise pass-through from the engine compartment  18  to the passenger compartment  20 . Flange portions  66  extend from the step portions  64  and are generally parallel to the planar portion  60 . A dash mat  70  is disposed between the flange portions  68  and the planar portion  60 . Preferably, an inboard surface  74  of the dash mat  70  abuts the step portions  64  of the dash  14 .  
         [0019]     The second mounting plate  26  includes a planar face  78  connected and laterally offset to a shoulder portion  80  by a neck  84 . The neck  84  offsets the planar face  78  from the shoulder portion  80  a sufficient distance to accommodate the second noise abating material  44  therein. The passages  32  are arranged on the planar face  78  to accommodate the pipes  30 . As with the first mounting plate  24 , the passages  32  have a diameter greater than the pipes  30  to allow a gap between the pipes  30  and the second mounting plate  26  in the assembled position. The gap precludes vibration between the pipes  30  and the second mounting plate  26  which diminishes noise translation from the pipes  30  to the dash  14  and ultimately to the passenger compartment  20 . A central hole  88  is arranged between the passages  32  to accept the stud  36 .  
         [0020]     The noise abating material  42  and  44  are configured to compress a predetermined amount during assembly. The first noise abating material  42  is bounded on its upright faces  90  by the respective planar portions  48  and  60  of the first mounting plate  24  and the dash  14 . The step portions  64  of the dash  14  bound opposite sides of the first noise abating material  42 . An outer radial surface  94  of the second noise abating material  44  is bound by an inner radial surface  96  ( FIG. 3 ) of the neck  84  of the second mounting plate  26 . The upright faces  100  of the second noise abating material  44  are bound by the inboard surface  102  ( FIG. 3 ) of the planar face  78  of the second mounting plate  26  and the planar face  60  of the dash  14 .  
         [0021]     The first noise abating material  42  includes a pair of holes  108  therein for accepting the pipes  30 . Likewise, the second noise abating material  44  includes a pair of holes  110  for accepting the pipes  30 . Each noise abating material  42  and  44  includes a central hole  114  and  116  respectively for accommodating the stud  36 . During assembly, the first and second noise abating material  42  and  44  are compressed within respective boundaries. The compression encourages tight contact between respective boundaries as well as tight contact with the outer circumferential walls of each pipe  30 . The preferred compression ratio of the first and second noise abating material  42 ,  44  is between 30% and 60% reduction. It is appreciated that other compression ratios may be employed.  
         [0022]     With particular reference to  FIGS. 3 and 4 , mounting the heater pipe assembly  10  into an installed position with the dash  14  will be described. In step  120  the pipes  30  are located through the opening  62  in the dash  14 . In step  124  the pipes  30  are located through the passages  108  in the first noise abating material  42 . In step  126 , the pipes  30  are located through the passages  56  in the first mounting plate  24 . In step  128  the second noise abating material  44  and mounting plate  26  are located around the pipes  30 . In step  130  an overlap distance C ( FIG. 3 ) is verified between the flange  52  of the first mounting plate  24  and the flange  66  of the dash  14 . The opening  62  in the dash  14  is configured to have sufficient clearance (gap A) with the heater pipes  30  such that the pipes  30  remain untouched by the dash  14  in an assembled position.  
         [0023]     During assembly, the first mounting plate  24  and the pipes  30  have a predetermined range of allowable lateral movement with respect to the dash  14 . The overlap distance C is sufficiently small enough to ensure the pipes  30  have clearance from the dash  14  (gap A). Explained further, one of the flanges  52  of the first mounting plate  24  will fall off the respective flange  66  of the dash  14  if shifted beyond a predetermined lateral amount. The predetermined amount ensures that the first mounting plate  24  will fall off the dash  14  prior to the dash  14  touching one of the pipes  30  indicating improper installation. In this way, if any overlap C is achieved during installation, a clearance (gap A) is also achieved verifying the pipes  30  are untouched by the dash  14 . In step  132  the heater pipe assembly  10  is tightened to the installed position by way of the stud  36  and fastener  38 . The stud  36  and the fastener  38  may alternatively comprise other fastening mechanisms. It is appreciated that the order of assembly is exemplary. For instance, the second mounting plate  26  and second noise abating material  44  may be positioned with respect to the pipes  30  prior to the first mounting plate  24  and the first noise abating material  42 .  
         [0024]     Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. For example, while the present invention has been described herein for use with a heater pipe assembly in an automobile, the same may be employed for a pipe, or other communication medium, extending between a boundary separating a first compartment with a second compartment having a noise source. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.