Abstract:
A working vehicle is provided with a traveling vehicle, a working section which is supported on a rotatable base, an operator&#39;s cab, and a connection section. The connection section includes: a connection section body which connects the rotatable base and the operator&#39;s cab and which is provided so as to be capable of pivoting about a base-side connection section connected to the rotatable base and about the operator&#39;s cab-side connection section connected to the operator&#39;s cab; and a pivot control section which extends so as to always intersect the connection section body in the range of pivoting of the connection section body, connects the rotatable base and the operator&#39;s cab, and is provided so as to be capable of pivoting about a base-side connection section connected to the rotatable base and about an operator&#39;s cab-side connection section connected to the operator&#39;s cab.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a working vehicle. In particular, the present invention relates to a working vehicle including a cab for operating a travelling vehicle and a working part, 
       BACKGROUND ART 
       [0002]    Conventionally, a working vehicle including a cab and a working part that are disposed on a slewing base provided on the upper side of a travelling vehicle is used. For example, a crane vehicle includes a slewing base that is turnable with respect to a travelling vehicle, and a cab and a crane part are disposed on the upper side of the stewing base, The crane part can be freely extended and contracted, and is contracted and laid along the travelling vehicle when the crane operation is completed. With this configuration, the travelling vehicle can stably travel. 
         [0003]    Here, in general, a crane part is longer than a travelling vehicle, and, when the crane part is laid along the travelling vehicle, the end part of the crane part protrudes from the front part of the travelling vehicle. In view of this, disadvantageously, the end part of the crane part can possibly block the visibility of the operator operating in the cab when the crane vehicle travels on the road. For example, when the crane vehicle enters an intersection and the end part of the crane part is located between the cab and the signal, the operator in the cab cannot clearly check the traffic light in some situation. 
         [0004]    In view of this, as a technique of maintaining the clear visibility of the operator in the cab during travel, PTL 1, for example, discloses a slewing excavator in which the cab is supported by a stewing arm such that the cab can be stewed to the rear part of the upper stewing body. When the stewing excavator travels on the road, the stewing excavator slews the cab to the rear side of the upper stewing body, and thus can prevent the working machine from blocking the visibility of the operator in the cab. 
       CITATION LIST 
     Patent Literature 
       [0005]    PTL 1 
       Japanese Unexamined Utility Model Registration Application Publication No. 61-58271 
     SUMMARY OF INVENTION 
     Technical Problem 
       [0006]    However, in the stewing excavator disclosed in PTL 1, the cab is turned along a large rotation radius around one support column that supports the stewing arm. In view of this, a large space is required to be provided around the cab to prevent the contact of the cab, and it is therefore difficult to efficiently utilize the space around the cab. 
         [0007]    To solve the above-mentioned conventional problems, an object of the present invention is to provide a working vehicle which can efficiently utilize the space around the cab. 
       Solution to Problem 
       [0008]    A working vehicle according to an embodiment of the present invention includes: a travelling vehicle; a working part that includes a stewing base turnably provided on an upper side of the travelling vehicle, and operates with a support of the stewing base; a cab mounted on the stewing base and configured for an operation of the travelling vehicle and the working part; and a coupling part that couples the cab and the slewing base such that an orientation of the cab is changeable with respect to the slewing base. the coupling part includes: a coupling part main body that couples the slewing base and the cab, and is turnable with a first base connecting part connected with the slewing base and a first cab connecting part connected with the cab, and a turning control part extended to intersect the coupling part main body at all times in a turning range of the coupling part main body and to couple the stewing base and the cab, the turning control part being turnable with a second base connecting part connected with the stewing base and a second cab connecting part connected with the cab, a distance between the first base connecting part of the coupling part main body and the second base connecting part of the turning control part and a distance between the first cab connecting part of the coupling part main body and the second cab connecting part of the turning control part are equal to each other, and a length from the first base connecting part to the first cab connecting part in the coupling part main body and a length from the second base connecting part to the second cab connecting part in the turning control part are equal to each other. 
         [0009]    Here, preferably, the coupling part main body is connected with the cab at a portion in the proximity of a center of gravity of the cab to support the cab. 
         [0010]    In addition, preferably, the coupling part main body is turned in a range of approximately 90 degrees. 
         [0011]    In addition, the cab is disposed on a side of the working part, the cab including at one side part thereof a door through which an operator enters or leaves the cab; and when changing an orientation of the cab such that the door faces the working part, the coupling part can turn the cab to form a space of a passage for the operator between the door and the working part. 
       Advantageous Effects of Invention 
       [0012]    According to the present invention, the orientation of the cab is changed with respect to the Mewing base by the coupling part main body and the turning control part, and thus a working vehicle which can efficiently utilize the space around the cab can be provided. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0013]      FIG. 1  is a side view illustrating a configuration of a working vehicle according to an embodiment of the present invention; 
           [0014]      FIG. 2  is a top view illustrating a configuration of a coupling part that couples a cab and a slewing base; 
           [0015]      FIG. 3  is a perspective view illustrating a crane vehicle in which the cab is in a travelling position; 
           [0016]      FIG. 4  illustrates a trajectory in the case where the cab is turned with the slewing base and the cab coupled with each other at one position; and 
           [0017]      FIG. 5  illustrates a trajectory in the case where the cab is turned with the slowing base and the cab coupled with each other by a coupling part main body and a turning control part. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0018]    An embodiment of the present invention is described below with reference to the accompanying drawings. 
         [0019]      FIG. 1  illustrates a configuration of a working vehicle according to an embodiment of the present invention. This working vehicle is a crane vehicle including travelling vehicle  1 , crane part  2  disposed on the upper side of travelling vehicle  1 , and cab  3  disposed on the upper side of travelling vehicle  1 . 
         [0020]    Travelling vehicle  1  is configured to support crane part  2  and cab  3  and travel on a road and the like, and includes outrigger  4  and wheel  5 . 
         [0021]    Outrigger  4  is configured to support the position of the crane vehicle during a crane operation, and is provided at a front part of and a rear part of travelling vehicle  1 . Outrigger  4  laterally overhangs from travelling vehicle  1 , and the end part thereof is grounded to thereby support the crane vehicle. 
         [0022]    Wheels  5  are provided between outriggers  4  disposed the front part and the rear part of travelling vehicle  1 . 
         [0023]    Crane part  2  is configured to perform a crane operation. Crane part  2  includes slowing base  6  that is turnably provided on the upper side of travelling vehicle  1 , boom  7  that is mounted on stewing base  6  such that boom  7  can be raised and lowered, and hook  8  that is disposed at the leading end part of boom  7 . Here, in  FIG. 1 , the reading end direction of boom  7  is the working direction, and the rear end direction of boom  7  is the travelling direction of travelling vehicle  1 . 
         [0024]    Stewing base  6  includes cab supporting part  9  disposed on the lower side of cab  3 , and bracket  10  uprightly provided on a side of cab  3 . Cab supporting part  9  has a flat plate shape, and is disposed to laterally overhang from the lower portion of bracket  10  to support the lower side of cab  3 . Bracket  10  supports boom  7 , and the rear end part of boom  7  is mounted thereto so as to be freely raised and lowered. Cab supporting part  9  and bracket  10  are provided to turn together on the upper side of travelling vehicle  1 . 
         [0025]    Boom  7  is extended from bracket  10  in the working direction and can be freely extended and contracted. Boom  7  has such a length that the leading end part protrudes from the rear part of travelling vehicle  1 , that is, protrudes to the working direction side, when boom  7  is laid along the top surface travelling vehicle  1  in the shortest state. 
         [0026]    Cab  3  is configured for operation of travelling vehicle  1  and crane part  2  by the operator, and is disposed on a side of crane part  2 . Here, cab  3  is disposed in operation position. P 1  in which front part  3   a  is oriented to the working direction of crane part  2 . In operation position P 1 , door  11  through which an operator enters or leaves cab  3  is provided at the right part of cab  3  that faces the side part of crane part  2 . 
         [0027]      FIG. 2  illustrates a top view of cab  3  and crane part  2 . Here,  FIG. 2  illustrates only main parts except for travelling vehicle  1 , boom  7 , and the like. 
         [0028]    As illustrated in  FIG. 2 , cab  3  is coupled with cab supporting part  9  of slewing base $ through coupling part  12 . Coupling part  12  is disposed to extend on the lower side of cab  3 , and couples cab  3  with cab supporting part  9  such that the orientation of cab  3  can be changed with respect to cab supporting part  9 . To be more specific, coupling part  12  includes coupling part main body  13  laterally extended substantially along the top surface of cab supporting part  9  to couple cab supporting part  9  and cab  3 , and turning control part  14  laterally extended to intersect coupling part main body  13  to couple cab supporting part  9  and cab  3 . 
         [0029]    Coupling part main body  13  is configured to turn cab  3  in the horizontal plane while supporting cab  3 . Coupling part main body  13  has a large width, and includes base connecting part  13   a  turnably connected to the upper part of cab supporting part  9  at one end portion thereof, and cab connecting part  13   b  turnably connected to the bottom part of cab  3  at the other end portion thereof. Base connecting part  13   a  is disposed in the proximity of bracket  10  of slewing base  6 , and cab connecting part  13   b  is disposed in the proximity of the center of gravity of cab  3 . In this manner, with coupling part main body  13  disposed to laterally extend from a portion in the proximity of a side part of bracket  10 , cab  3  is disposed at a position separated from the side part of bracket  10 . 
         [0030]    Turning control part  14  controls the turning of cab  3  with coupling part main body  13 . Turning control part  14  includes base connecting part  14   a  turnably connected to the upper part of cab supporting part  9  at one end portion thereof, and cab connecting part  14   b  turnably connected to the bottom part of cab  3  at the other end portion thereof. Base connecting part  14   a  is disposed between cab  3  and bracket  10 , and cab connecting part  14   b  is disposed in the proximity of a left side part of cab  3 . 
         [0031]    Base connecting part  14   a  and cab connecting part  14   b  are disposed at a position to sandwich coupling part main body  13  therebetween such that turning control part  14  intersects coupling part main body  13  at all times in a turning range of coupling part main body  13 . 
         [0032]    To be more specific, the parts are disposed such that the distance from base connecting part  14   a  to base connecting part  13   a  of coupling part main body  13 , and the distance from cab connecting part  14   b  to cab connecting part  13   b  of coupling part main body  13  are equal to each other. Further, the parts are disposed such that the length from base connecting part  14   a  to cab connecting part  14   b  in turning control part  14  is equal to the length from base connecting part  13   a  to cab connecting part  13   b  in coupling part main body  13 . 
         [0033]    By disposing base connecting part  14   a  and cab connecting part  14   b  in the above-mentioned manner, turning control part  14  can be turned to follow the turning of coupling part main body  13 . Here, coupling part main body  13  is turned by driving of turning driving part  15  disposed in cab supporting part  9 . 
         [0034]    Turning driving part  15  is connected with base connecting part  13   a  of coupling part main body  13  and an oil pressure circuit part not illustrated. Operation oil is supplied to turning driving part  15  from the oil pressure circuit part, and turning driving part  15  drives coupling part main body  13  to turn through base connecting part  13   a.    
         [0035]    Next, an operation of changing the orientation of cab  3  in association with the turning of coupling part  12  is described in detail. 
         [0036]    As illustrated in  FIG. 3 , cab  3  in operation position P 1  is turned approximately 180 degrees into travelling position P 2  in which front part  3   a  faces the travelling direction of travelling vehicle  1 , that is, the rear end direction of boom  7 . 
         [0037]    At this time, in the case where cab  3  and cab supporting part  9  are turnably coupled with each other at one position with one coupling part E extending in the vertical direction as illustrated in  FIG. 4 , cab  3  is turned along trajectory Ta having a predetermined rotation radius along with the rotation of coupling part E around the axis of coupling part E. 
         [0038]    In contrast, in the case where cab supporting part  9  and cab  3  are turnably coupled with each other with coupling part main body  13  and turning control part  14  of coupling part  12  by an intersection link mechanism, cab connecting part  14   b  of turning control part  14  connected at a portion in the proximity of the left side part of cab  3  moves to approach base connecting part  13   a  of coupling part main body  13  along with the turning of coupling part main body  13  of cab  3  by coupling part main body  13  from operation position P 1  to travelling position P 2  as illustrated in  FIG. 5 . As a result, in travelling position P 2 , cab connecting part  14   b  is moved to a portion in the proximity of the intermediate portion between cab connecting part  13   b  and base connecting part  13   a  of coupling part main body  13 . 
         [0039]    In this manner, when cab connecting part  14   b  moves to approach base connecting part  13   a  of coupling part main body  13  along with the turning of coupling part main body  13 , the left side part of cab  3  connected with cab connecting part  14   b  is immediately pulled toward bracket  10  side, and cab  3  can be turned along trajectory Tb having a small rotation radius. It is to be noted that, with the configuration in which turning control part  14  intersects coupling part main body  13  when cab  3  is set in travelling position P 2 , the intersecting state between turning control part  14  and coupling part main body  13  can be maintained at all times in a turning range of coupling part main body  13 . 
         [0040]    Next, an operation of the present embodiment is described. 
         [0041]    First, cab  3  is set in operation position P 1  as illustrated in  FIG. 1 , and a crane operation of crane part  2  is performed in the state where the crane vehicle is supported with outrigger  4 . At this time, as illustrated in  FIG. 2 , coupling part main body  13  of coupling part  12  is laterally extended from a portion in the proximity of the side part of bracket  10  of crane part  2 , and accordingly, cab  3  is disposed at a position separated from the side part of bracket  10 . 
         [0042]    In operation position P 1 , door  11  is provided at the right part of cab  3  that faces the side part of bracket  10 , and, by disposing cab  3  at a position separated from bracket  10 , the passage for the operator who enters or leaves cab  3  through door  11  can be provided. In addition, it is possible to prevent the side part of bracket  10  from blocking the visibility ,  of the operator operating cab  3 , and thus the operator can perform an operation of crane part  2  while clearly checking hook  8  mounted at the leading end of boom  7  from cab  3 . 
         [0043]    When the crane operation of crane part  2  is completed, boom  7  is contracted and laid along the top surface of travelling vehicle  1 , and, outrigger  4  is housed in travelling vehicle  1 . Here, the leading end part of boom  7  protrudes from the rear part of travelling vehicle  1 , and therefore, if travelling vehicle  1  travels in the direction of the leading end of boom  7  with cab  3  set in operation position P 1 , the leading end part of boom  7  can possibly block the visibility of the operator operating in cab  3 . 
         [0044]    In view of this, as illustrated in  FIG. 3 , the orientation of cab  3  is changed from operation position P 1  to travelling position P 2 . To be more specific, as illustrated in  FIG. 5 , turning driving part  15  rotates base connecting part  13   a  of coupling part main body  13  around the axis thereof, and thus coupling part main body  13  turns such that cab connecting part  13   b  moves to the rear part side of crane part  2 . Along with the turning of coupling part main body  13 , turning control part  14  disposed to intersect coupling part main body  13  is also turned, and cab connecting part  14   b  of turning control part  14  that is disposed at a portion in the proximity of the left side part of cab  3  in operation position P 1  moves to approach base connecting part  13   a  of coupling part main body  13 . 
         [0045]    In this manner, when cab connecting part  14   b  of turning control part  14  moves to approach base connecting part  13   a  of coupling part main body  13  along with the turning of coupling part main body  13 , the left side part of cab  3  connected with cab connecting part  14   b  is immediately pulled toward bracket  10  side, and thus cab  3  can be turned along trajectory Tb having a small rotation radius. 
         [0046]    At this time, since cab connecting part  13   b  of coupling part main body  13  is disposed in the proximity of the center of gravity of cab  3 , cab  3  can be surely supported, and the turning of cab  3  can be stably performed. 
         [0047]    In this manner, when cab connecting part  14   b  of turning control part  14  is located in the proximity of base connecting part  13   a  of coupling part main body  13 , the orientation of cab  3  is changed to travelling position P 2  at 180 degrees to operation position P 1 . At this time, preferably, coupling part main body  13  turns in a range of approximately 90 degrees from operation position P 1  to travelling position P 2 , and in this manner, the orientation of cab  3  can be surely changed from operation position P 1  to travelling position P 2 . 
         [0048]    When the orientation of cab  3  is changed to travelling position P 2 , travelling vehicle  1  travels in the rear end direction of boom  7  by the operation of the operator. At this time, the leading end part of boom  7  is located on the rear side of cab  3 , and thus the clear visibility of the operator operating in cab  3  can be maintained. 
         [0049]    Here, preferably, the orientation of cab  3  is changed by coupling part  12  such that front part  3   a  protrudes from the rear part of bracket  10  of crane part  2  as illustrated in  FIG. 3 . In this manner, by disposing front part of  3   a  of cab  3  to protrude from the rear part of bracket  10 , the operator in cab  3  can operate travelling vehicle  1  while clearly checking the travelling direction of travelling vehicle  1 . 
         [0050]    According to the present embodiment, since cab  3  is turned with a small rotation radius with coupling part main body  13  and turning control part  14 , it is not necessary to provide a large space tor preventing contact of cab  3  at the time when the orientation of cab  3  is changed, and the space around cab  3  can be efficiently utilized. 
         [0051]    While coupling part  12  is provided in a crane vehicle including crane part  2  in the above-mentioned embodiment, coupling part  12  can be provided any working vehicles including a working part that operates with support of stewing base  6 . For example, coupling part  12  can be provided in an excavator and the like. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1  Travelling vehicle 
           2  Crane part 
           3  Cab 
           3   a  Front part of cab 
           4  Outrigger 
           5  Wheel 
           6  Stewing base 
           7  Boom 
           8  Hook 
           9  Cab supporting part 
           10  Bracket 
           11  Door 
           12  Coupling part 
           13  Coupling part main body 
           13   a  Base connecting part 
           13   b  Cab connecting part 
           14  Turning control part 
           14   a  Base connecting part 
           14   b  Cab connecting part 
           15  Turning driving part 
         P 1  Operation position 
         P 2  Travelling position 
         Ta, Tb Trajectory of cab 
         E Coupling part