Abstract:
A cab includes a cab frame forming the cab, an outer roof configured to cover said cab frame from above and to be fastened to the cab frame from above, a seal mount protruding downwardly from an edge of the outer roof, and a seal material including a body portion having a recess for receiving the seal mount. The periphery of the body portion of the seal material has a seal lip for contacting said cab frame for sealing, and a drain groove for draining water entering between said seal material and said cab frame.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates to a cabin, and more particularly to a seal structure for a vehicle cabin. 
         [0002]    A known seal structure for a cabin (referred to as cab), as disclosed in JP 8-133123, for example, has an outer roof tightened from above to a cab frame through a seal member to seal a gap between the outer roof and cab frames. Another known seal structure for a cab, as disclosed in JP 11-91639, a seal material is fitted in an elastically deformed state between a peripheral portion of a top board and a top board support to seal a gap between the top board and a cab frame. 
         [0003]    In the conventional seal structure for a cab disclosed in JP 8-133123, the outer roof is tightened and fixed from above, and its tightening force presses the seal member on the cab frame, thereby securing sealing performance between the outer roof and cab frame. However, the seal member performs sealing action in only one location. When, for example, the seal member becomes depleted or the tightening force weakens, there arises a problem that water can easily leak into the cab. 
         [0004]    In the conventional seal structure for a cab disclosed in JP 11-91639, the seal material is elastically deformed, and a restoring force of the elastic deformation is used to secure sealing performance between the top board and cab frame. However, the restoring force due to the elastic deformation of the seal material is weak. When, for example, the seal material becomes depleted, there arises a problem that water can easily leak into the cab. 
       SUMMARY OF THE INVENTION 
       [0005]    The object of this invention is to realize a seal structure for a cab that produces improved sealing performance between an outer roof and a cab frame. 
         [0006]    A cab according to this invention comprises: 
         [0007]    a cab frame forming the cab; 
         [0008]    an outer roof configured to cover said cab frame from above and to be fastened to the cab frame from above; 
         [0009]    a seal mount protruding downwardly from an edge of the outer roof; and 
         [0010]    a seal material including a body portion having a recess for receiving the seal mount, a periphery of the body portion of the seal material having a seal lip for contacting said cab frame for sealing, and a drain groove for draining water entering between said seal material and said cab frame. 
         [0011]    According to this characteristic, drain grooves are formed laterally of the body portion of the seal material for draining water entering between the seal material and the cab frame. The water entering between the seal material and the cab frame can be drained smoothly through the drain grooves. Thus, water is prevented from stagnating between the seal material and the cab frame. 
         [0012]    The body portion and seal lips of the seal material have sealing effects in two locations between the outer roof and cab frame. This improves sealing performance between the outer roof and cab frame. 
         [0013]    That is, according to this invention, since water is prevented from stagnating between the seal material and cab frame, water can hardly enter the cab from between the seal material and cab frame, thereby improving sealing performance between the outer roof and cab frame. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a left-hand side elevation of a utility vehicle; 
           [0015]      FIG. 2  is a plan view of the utility vehicle; 
           [0016]      FIG. 3  is a plan view of an outer roof; 
           [0017]      FIG. 4  is a vertical section taken on line IV-IV of  FIG. 3 ; 
           [0018]      FIG. 5  is a vertical section taken on line V-V of  FIG. 3 ; 
           [0019]      FIG. 6  is a vertical section taken on line VI-VI of  FIG. 3 ; and 
           [0020]      FIG. 7  is a detailed view showing a sectional structure of a seal material. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0021]    [Overall Construction of Utility Vehicle] 
         [0022]      FIG. 1  shows a side elevation of a utility vehicle which is one example of working vehicles.  FIG. 2  shows a plan view of the utility vehicle. The utility vehicle is constructed to be the four-wheel drive type for transmitting power from an engine  2  mounted in a vibration-proofing manner on a vehicle body frame  1 , through a gear type change speed device  4  and a hydrostatic stepless transmission  3 , to right and left front wheels  5  and right and left rear wheels  6 . 
         [0023]    As shown in  FIGS. 1 and 2 , the utility vehicle includes, arranged on a front part thereof, lower covers  7  acting also as front wheel fenders, an upper cover  8  opening in an upper, transversely middle portion thereof, and a hood  9  pivotably openable and closable to openably cover the opening of the upper cover  8 . 
         [0024]    The utility vehicle includes a cab  14  disposed in a longitudinally middle position thereof and having a steering wheel  11  for steering the front wheels  5 , and a driver&#39;s seat  12 . The cab  14  defines a boarding space therein. 
         [0025]    A hydraulic dump cylinder  15  is disposed in a rearward position of the utility vehicle and above the gear type change speed device  4 . The dump cylinder  15  is extendible and contractible for vertically rocking a loading platform  17  to take dumping action about a pivot shaft  16  extending transversely in a rear end unit region of the vehicle body frame  1 . 
         [0026]    The vehicle body frame  1  includes a cab frame  20  for forming the boarding space, and a front frame  18  and a rear frame  19  extending forward and rearward from the cab frame  20 . The various frames  18 ,  19 ,  20  and so on constituting the vehicle body frame  1  are firmly connected together by welding. 
         [0027]    The cab frame  20  includes a pair of right and left door frames  21  each defining an entrance, a plurality of cross members  22  extending between the right and left door frames  21 , a floor panel  23  defining a floor of the boarding space, a support frame  24  for supporting the driver&#39;s seat  12 , and front and rear roof panels ( FIG. 3 ) for supporting an outer roof  31  and an inner roof  36  forming a ceiling of the boarding space. A front plane and a rear plane of the cab frame  20  are covered with an openable windshield  26  and an openable rear glass pane  27 , respectively. 
         [0028]    The pair of right and left door frames  21  each defining an entrance is formed by bending a square steel pipe into a loop shape. Each door frame  21  has an upper inner portion recessed over the entire circumference thereof. The recess defines a frame receiver  21   a  and a seal portion  21   b  ( FIG. 5 ). 
         [0029]    The door frames  21  located at opposite sides of the cab frame  20  have doors  28 . When an open/close handle  29  is operated from inside or outside, each of the right and left doors  28  of the outswinging type opens and closes in a single swing mode about a vertical axis of hinges  30  disposed in upper and lower positions at the front of the door  28 . 
         [0030]    [Detailed Construction of Outer Roof and Adjacent Components] 
         [0031]      FIG. 3  is a plan view showing the construction of the outer roof  31  and adjacent components.  FIG. 4  is a section taken on line IV-IV of  FIG. 3 . As shown in  FIGS. 3 and 4 , the front and rear roof panels  25  are formed to have shapes fitting with the outer roof  31  and inner roof  36  to be described hereinafter, respectively. Front parts of the front roof panel  25  and rear parts of the rear roof panel  25  are dented inward to form recesses  25   a , and bolts  35  are fixed to the recesses  25   a  for attaching the outer roof  31 . 
         [0032]    The front and rear roof panels  25  have flange portions  25   c  extending over the entire lengths of the right and left sides thereof. The roof panels  25  are secured to the door frame  21 , with the Range portions  25   c  placed on the frame receivers  21   a  of the door frame  21  ( FIG. 5 ). 
         [0033]    The outer roof  31  is constructed by pressing an ABS resin plate and coating the outer surface with acrylic sheet. The outer roof  31  has front parts and rear parts dented downward to form recesses  31   a . Mounting bores are formed in the recesses  31   a  for receiving the bolts  35  therethrough to attach the outer roof  31 . The outer roof  31  has hinge mounts  31   c  projecting upward from the front end thereof. In this way, the outer roof  31  covers, from above, hinges  37  at the upper end of the windshield  26 . Thus, the hinges  37  do not rust easily, and appearance is improved also. 
         [0034]    The opposite sides of the outer roof  31  are bent downward over the entire lengths thereof to form seal mounts  31   d . A seal material  40  is attached to each seal mount  31   d  as described hereinafter ( FIG. 5 ). The seal material  40  is attached to each seal mount  31   d  of the outer roof  31  to extend between a front end and a rear end of the seal mount  31   d . The seal material  40  has a front end and a rear end thereof exposed outside the vehicle to drain water such as rain water outside the vehicle through drain grooves  48 - 50  described hereinafter. 
         [0035]    As shown in  FIG. 4 , the door frame  21  and outer roof  31  are curved forward and backward, so that the drain grooves  48 - 50  formed in the seal material  40  may be inclined forward and backward. Thus, by effectively using such inclinations water can be drained smoothly forward and backward. 
         [0036]    The outer roof  31  has a sound-absorbing waterproof sheet  32  pasted to an entire area of the lower surface thereof. The sound-absorbing waterproof sheet  32  has a three-layer structure including a sound-absorbing waterproof sponge, a sound insulation sheet and a sound-absorbing waterproof sponge ( FIG. 5 ). Even when water enters areas over upper surfaces of the roof panels  25  through the seal materials  40  from the outer roof  31 , the water is absorbed by the sound-absorbing waterproof sheet  32 . In addition, sound from outside the vehicle is absorbed by the sound-absorbing waterproof sheet  32 , and thus is hardly transmitted to the interior of the cab  14 . 
         [0037]    The outer roof  31 , with the seal materials  40  attached thereto, is placed in tight contact with the front and rear roof panels  25 , and is fastened tight to the roof panels  25  from above through rubber plates  33  and presser plates  34  after positionally adjusting the bolts  35  of the roof panels  25  and the mounting bores in the recesses  31   a  of the outer roof  31 . By employing the construction for fastening from above the outer roof  31  with the seal materials  40  attached to the peripheral portions thereof the efficiency of assembling work can be improved and manufacturing cost reduced. 
         [0038]    The construction for fastening the outer roof  31  from above to the front and rear roof panels  25 , with the sound-absorbing waterproof sheet  32  interposed between the outer roof  31  and roof panels  25 , the force fastening the outer roof  31  tight acts as a force that presses the sound-absorbing waterproof sheet  32  adhering to the outer roof  31  against the front and rear roof panels  25 , to secure sealing performance between the front and rear parts of the outer roof  31  and the roof panels  25 . 
         [0039]    When, for example, the utility vehicle moves forward, water may enter from a space between the windshield  26  and the front end of the outer roof  31 , backward into the space between the outer roof  31  and roof panels  25 . Even so, the water is absorbed by the sound-absorbing waterproof sheet  32  interposed between the outer roof  31  and roof panels  25 , thereby preventing the water from entering the cab  14 . In this way, sealing performance is secured for the space between the front end of the outer roof  31  and roof panel  25 . When water enters from a space between the rear glass pane  27  and the rear end of the outer roof  31 , the sound-absorbing waterproof sheet  32  similarly secures sealing performance for the space between the rear end of the outer roof  31  and roof panel  25 . 
         [0040]    Below the roof panels  25 , the inner roof  36  is fixed to cover an entire ceiling area of the cab  14 , the inner roof  36  being formed of a heat insulator and a nonwoven fabric curved to fit with the shape of the roof panels  25 . The inner roof  36  serves to keep the temperature and the like in the cab  14  comfortable. 
         [0041]    [Detailed Construction of Seal Material] 
         [0042]      FIGS. 5 through 7  show a detailed construction of the seal material  40 . 
         [0043]      FIG. 5  shows a section taken on line V-V of  FIG. 3 , with the seal material  40  attached.  FIG. 6  shows a section taken on line VI-VI of  FIG. 3 , with the seal material  40  attached.  FIG. 7  shows a section of the seal material  40  not attached.  FIGS. 5 through 7  show a seal structure on the left-hand side of the outer roof  31 . A right-hand seal structure is the same except the right and left features.  FIG. 5  shows a seal structure at the opposite sides of the front roof panel  25 . A seal structure at the opposite sides of the rear roof panel  25  is similar to what is shown in  FIG. 5  (see  FIG. 3 ). 
         [0044]    As shown in  FIGS. 5 through 7 , the seal material  40  is formed of EPDM, has a sectional shape defining, as integral parts thereof, seal lips  42 - 45  and first and second tongues  46  and  47  to be described hereinafter. 
         [0045]    The seal material  40  includes a body portion  41  attachable to the outer roof  31 , seal lips  42 - 45  formed on inward and outward sides of the body portion  41 , and first and second tongues  46  and  47  extending upward from the body portion  41 . 
         [0046]    As shown in  FIGS. 5 and 7 , the body portion  41  of the seal material  40  has a channel-shaped section opening upward, defining an upwardly opening recess  41   a  extending over the entire length of the seal material  40 . When the outer roof  31  is fixed from above, with the seal material  40  attached to the outer roof  31 , a lower surface of the body portion  41  is placed in tight contact with the upper surface of the flange portion  25   c  of the roof panel  25 . This provides a seal between the flange portion  25   c  of the roof panel  25  and the lower surface of the body portion  41 . 
         [0047]    The seal lip  42  is formed to protrude obliquely upward from an upper inward position of the body portion  41  and to extend over the entire length of the seal material  40 . The seal lip  42  has a tip end of smooth, rounded shape. When the outer roof  31  is fixed from above, with the seal material  40  attached to the outer roof  31 , a lower surface of the seal lip  42  elastically deforms through contact with the sound-absorbing waterproof sheet  32 . Thus, the seal lip  42  is pressed against the sound-absorbing waterproof sheet  32  to secure sealing performance inwardly of the outer roof  31 . 
         [0048]    By forming the seal lip  42  to protrude obliquely upward as noted above, a drain groove  48  having a substantially triangular sectional shape can be formed above the seal lip  42 . Thus, water entering from between a lower surface of the second tongue  47  and the outer roof  31  through the recess  41   a  is drained from the drain groove  48  forwardly of the vehicle. 
         [0049]    The seal lip  43  of triangular sectional shape is formed to protrude inward from a lower inward position of the body portion  41  and to extend over the entire length of the seal material  40 . When the outer roof  31  is fixed from above, with the seal material  40  attached to the outer roof  31 , the seal lip  43  contacts an upper surface of the roof panel  25 . This provides a seal inwardly of the outer roof  31  to stop water not stopped or absorbed by the seal lip  42  and sound-absorbing waterproof sheet  32  from entering the cab  14 . 
         [0050]    The seal lip  44  is formed to protrude obliquely upward from a middle outward position of the body portion  41  and to extend over the entire length of the seal material  40 . The seal lip  44  has a tip end of smooth, rounded shape. When the outer roof  31  is fixed from above, with the seal material  40  attached to the outer roof  31 , the tip end of the seal lip  44  elastically deforms through contact with the seal portion  21   b  of the door frame  21 . Thus, the tip end of the seal lip  44  is pressed against the seal portion  21   b  of the door frame  21  to secure sealing performance outwardly of the outer roof  31 . 
         [0051]    By forming the seal lip  44  to protrude obliquely upward as noted above, a drain groove  49  having a substantially triangular sectional shape can be formed above the seal lip  44 . Thus, water entering from between a lower surface of the first tongue  46  and the door frame  21  is stopped by the seal lip  44  and drained from the drain groove  49  forwardly of the vehicle. 
         [0052]    The seal lip  45  is formed to protrude obliquely downward from a lower outward position of the body portion  41  and to extend over the entire length of the seal material  40 . The seal lip  45  has a tip end of smooth, rounded shape for contacting the door frame  21 . When the outer roof  31  is fixed from above, with the seal material  40  attached to the outer roof  31 , the tip end of the seal lip  45  elastically deforms through contact with the seal portion  21   b  of the door frame  21 . Thus, the tip end of the seal lip  45  is pressed against the seal portion  21   b  of the door frame  21 . This provides a seal outwardly of the outer roof  31  to stop water not stopped by the seal lip  44  from entering the cab  14 . 
         [0053]    A drain groove  50  is defined by the seal lips  44  and  45  and door frame  21 . Even when water not stopped by the seal lip  44  enters from between the seal lip  44  and door frame  21 , the water is drained from the drain groove  50  forwardly of the vehicle. 
         [0054]    The first tongue  46  extends outward from an upper outward position of the body portion  41  to cover a gap between the body portion  41  and the door frame  21  forming part of the cab frame  20 . The first tongue  46  has a lower surface thereof formed to fit with the shape of the door frame  21 , and an upper surface smoothly curved so that water may flow smoothly outward and downward. The first tongue  46  has a tip end of smooth, rounded shape. When the outer roof  31  is fixed from above, with the seal material  40  attached to the outer roof  31 , the tip end of the first tongue  46  elastically deforms through contact with the seal portion  21   b  of the door frame  21  to secure sealing performance between the tip end of the first tongue  46  and the outer roof  31 . 
         [0055]    The second tongue  47  extends inward from the upper outward position of the body portion  41  to cover the outer roof  31  from above. The second tongue  47  has a lower surface thereof formed to fit with the shape of the outer roof  31 , and an upper surface smoothly curved. The second tongue  47  has a tip end of smooth, rounded shape. When the seal material  40  is attached to the outer roof  31 , the tip end of the second tongue  46  elastically deforms through contact with the outer roof  31  to secure sealing performance between the tip end of the second tongue  47  and the outer roof  31 . 
         [0056]    The seal material  40  is constructed as described above, and the outer roof  31  is fixed from above, with the seal material  40  attached to the outer roof  31 . Then, the first tongue  46  covers, from above, the part of the door frame  21  located outwardly of the outer roof  31 , to stop entry of water. Even if water enters from between the first tongue  46  and door frame  21 , the seal lips  44  and  45  will doubly prevent the water from entering the cab  14 . The entering water can be drained outside through the drain grooves  49  and  50 . 
         [0057]    On the other hand, inwardly of the outer roof  31 , the second tongue  47  covers the outer roof  31  from above, to stop entry of water. Even if water enters from between the second tongue  47  and outer roof  31 , the seal lips  42  and  43  will doubly prevent the water from entering the cab  14 . The entering water can be drained outside through the drain groove  48 . Part of the water flowing over the seal lip  42  and leaking inward from the drain groove  48  will be absorbed by the sound-absorbing waterproof sheet  32  without leaking into the cab  14 . 
         [0058]    Further, by fixing the outer roof  31  from above, the outer roof  31  itself, which is formed of resin, elastically deforms to a small extent. A restoring force from the elastic deformation of the outer roof  31  acts as a force to pushing downward the seal mount  31   d  bent downward. This secures sealing performance between the body portion  41  and flange portion  25   c , and between the seal lip  43  and the upper surface of the roof panel  25 . 
         [0059]    A seal structure in a middle portion in the fore and aft direction of the outer roof  31  where the roof panels  25  are not present will be described with reference to  FIG. 6 , As shown in  FIG. 6 , when the outer roof  31  is fixed from above, with the seal material  40  attached to the outer roof  31 , the tip end of the seal lip  42  formed in the upper inward position of the body portion  41  elastically deforms through contact with the sound-absorbing waterproof sheet  32 . This secures sealing performance inwardly of the outer roof  31  even if water enters from between the second tongue  47  and outer roof  31  through the recess  41   a.    
         [0060]    Water entering from between the second tongue  47  and outer roof  31  through the recess  41  is drained forward or rearward of the vehicle through the drain groove  48  formed above the seal lip  42 . 
         [0061]    The tip end of the seal lip  44  formed in the middle outward position of the body portion  41  elastically deforms through contact with the seal portion  21   b  of the door frame  21 . The tip end of the seal lip  45  formed in the lower outward position of the body portion  41  elastically deforms through contact with the frame receiver  21   a  of the door frame  21 . Even if water enters from between the first tongue  46  and door frames  21 , the seal lip  44  and seal lip  45  secure sealing performance in two positions outwardly of the outer roof  31 . 
         [0062]    Water entering from between the first tongue  46  and door frame  21  is drained forward or rearward of the vehicle through the drain groove  49  formed above the seal lip  44  and the drain groove  50  formed above the seal lip  45 . 
         [0063]    As described above, the outer roof  31  in the middle portion in the fore and aft direction is constructed to present a different sectional shape to the front and rear ends of the outer roof  31  having the roof panels  25  as shown in  FIG. 5 . With this construction, while fully securing seal performance between the outer roof  31  and door frames  21  at the front end and rear end of the outer roof  31  where water can enter easily, the outer roof  31  in the middle portion in the fore and aft direction, where water does not enter so easily as at the front end and rear end of the outer roof  31 , is sealed without the roof panels  25 . This simplifies the frame structure, thereby lightening the vehicle body and reducing manufacturing cost. 
       First Modified Embodiment of the Invention 
       [0064]    In the above embodiment, the outer roof  31  with the seal materials  40  attached thereto is fixed to the cab frame  21  with bolts  35  from above. A different construction may be employed used for fastening and fixing the outer roof  31  with the seal materials  40  attached thereto to the cab frame  21  from above. 
         [0065]    In the above embodiment, the seal materials  40  are used to seal gaps between outer roof  31  and door frame  21  at the opposite sides of the outer roof  31 . It is possible to employ a different construction where the seal materials  40  seal gaps between the outer roof  31  and other frames constituting the cab frame  21 . For example, the seal materials  40  may be attached over the entire circumference of the outer roof  31 . 
       Second Modified Embodiment of the Invention 
       [0066]    In the above embodiment, the seal lips  42 - 45 , drain grooves  48 - 50  and the first and second tongues  46  and  47  have the described shapes. The seal lips  42 - 45 , drain grooves  48 - 50  and the first and second tongues  46  and  47  of other shapes may be employed as long as similar functions are fulfilled. 
       Third Modified Embodiment of the Invention 
       [0067]    In the above embodiment, the invention is applied to the seal structure of the cab  14  of the utility vehicle shown as an example of working vehicles. The invention is equally applicable to the seal structure of cabs  14  of other types of working vehicle, e.g. agricultural working vehicles such as tractors and combines, and construction working vehicles such as backhoes and wheel loaders.