Patent Publication Number: US-10323380-B2

Title: Coupling pin extracting apparatus and working machine provided with same

Description:
TECHNICAL FIELD 
     The present invention relates to a coupling pin extracting apparatus, and a working machine provided with same. 
     BACKGROUND ART 
     For example, Japanese Laid-Open Patent Publication No. 2009-13730 recites a jig for removing a coupling pin which couples coupling bodies from a pin hole (hole portion). According to the technique recited in the literature (see FIG. 8 and FIG. 9), a cylinder and a coupling pin are arranged coaxially, so that extension of the cylinder pushes out the coupling pin from the pin hole. 
     According to the technique recited in the literature, when a coupling pin is pushed out from a pin hole, components of the jig are arranged inside the pin hole. On this occasion, for example, moving of a coupling body or the like might cause the components of the jig arranged inside the pin hole and the pin hole to come into contact with each other. As a result, the jig might be damaged. 
     Additionally, since the jig is used for removing a coupling pin from a pin hole, a length of the jig in an axial direction of the coupling pin (a coupling pin axial direction) is expected to matter. For this reason, it is demanded to reduce a length of the jig in the coupling pin axial direction. 
     SUMMARY OF INVENTION 
     An object of the present invention is to prevent, in a coupling pin extracting apparatus which extracts a coupling pin from a pin hole and in a working machine provided therewith, a component of a jig from coining into contact with an inner circumference surface of the pin hole when the coupling pin is removed from the pin hole, while reducing a length of the jig in an axial direction of the coupling pin. 
     A coupling pin extracting apparatus according to the present invention is provided in a working machine. The working machine includes a first coupling body, a second coupling body, and a coupling pin. The first coupling body has a pin hole opened. The second coupling body is arranged adjacent to the first coupling body and has a pin hole opened. The coupling pin is inserted into the pin holes to couple the first coupling body and the second coupling body. The coupling pin extracting apparatus extracts the coupling pin from the pin hole in an axial direction. The coupling pin extracting apparatus includes a frame, at least one cylinder, and a connection member. The frame is attached to the first coupling body to be opposed to the pin hole on a side opposite to the second coupling body in the axial direction of the coupling pin. The frame defines a space portion which accepts the coupling pin extracted from the pin hole. At least one cylinder is arranged to be opposed to the space portion in a direction orthogonal to the axial direction. The cylinder has a cylinder fixed portion which is fixed to the frame, and a cylinder movable portion which is fit on the cylinder fixed portion and is movable relative to the cylinder fixed portion. The connection member connects the coupling pin and the cylinder movable portion with each other such that the coupling pin is extracted from the pin hole in the axial direction and is also guided to the space portion in association with extension operation of the cylinder caused by relative movement of the cylinder movable portion. 
     Additionally, the working machine according to the present invention includes a main body portion including a slowing frame, a boom attached to the slewing frame in a raisable and lowerable manner, a boom foot pin which couples the slewing frame and the boom to allow the boom to be raised and lowered, and the above coupling pin extracting apparatus. The first coupling body includes the slewing frame, the second coupling body includes the boom, and the coupling pin includes the boom foot pin. The boom foot pin is designed to be inserted into the pin holes opened in the slewing frame and a base end portion of the boom. The coupling pin extracting apparatus extracts the boom foot pin from the pin hole. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a view of a working machine seen from above, which shows a frame in a projected state and a cylinder in a contracted state; 
         FIG. 2  is a view of the working machine shown in  FIG. 1  when seen from the side: 
         FIG. 3  is a view of a coupling pin extracting apparatus and the like shown in  FIG. 1  when seen from above; 
         FIG. 4  shows  FIG. 3  seen from an arrow of F 4 ; 
         FIG. 5  shows  FIG. 3  seen from an arrow of F 5 ; 
         FIG. 6  is a schematic view of the coupling pin extracting apparatus seen from an axial direction of a coupling pin when four cylinders as shown in  FIG. 5  are provided; 
         FIG. 7  is a view of the coupling pin extracting apparatus and the like when the cylinders shown in  FIG. 3  are in an extended state, which are seen from above; and 
         FIG. 8  is a view of the coupling pin extracting apparatus and the like when the frame shown in  FIG. 3  is in a stored state, which are seen from above. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     With reference to  FIG. 1  to  FIG. 8 , description will be made of a working machine  1  having a coupling pin attaching/detaching apparatus  40  (a coupling pin extracting apparatus) according to one embodiment of the present invention. 
     The working machine  1  is a machine which conducts work. The working machine  1  conducts, for example, construction work. The working machine  1  may be a machine which conducts work other than construction work. The working machine  1  is, for example, a crane, or a movable crane. The working machine  1  includes a lower travelling body  5  (see  FIG. 2 ), an upper slewing body  10  (a main body portion), a boom  20  (a second coupling body), a coupling pin  30 , and the coupling pin attaching/detaching apparatus  40 . 
     The lower travelling body  5  causes the working machine  1  to travel ( FIG. 2 ). The lower travelling body  5  may include, for example, a crawler not shown, or a wheel not shown. 
     The upper slewing body  10  (the main body portion) is attached to the lower travelling body  5  so as to be turnable with respect to the lower travelling body  5 . The upper slewing body  10  includes a slewing frame  11  (a first coupling body), a counter weight  13 , a cab  15 , and a guard  17 . 
     The slewing frame  11  (the first coupling body) is a structure to which the counter weight  13 , the cab  15  and the like are attached and has a shape elongating along a front-back direction in  FIG. 2 . The direction in which the slewing frame  11  thus extends is defined as a longitudinal direction of the slewing frame  11 . As shown in  FIG. 1 , a center line of the slewing frame  11 , which is a center line extending in the longitudinal direction of the slewing frame  11  (a longitudinal direction of a main body portion of the working machine  1 ), is defined as a slewing frame center line  11   a . The slewing frame  11  includes a pair of boom attaching portions  11   b.    
     (Direction of Working Machine) 
     The direction in which the slewing frame center line  11   a  extends is defined as a front-back direction (X) of the working machine  1 . In the front-hack direction, a direction heading from the counter weight  13  to the cab  15  is defined as a forward direction (X 1 ) and a reverse direction thereof is defined as a backward direction (X 2 ). A horizontal direction orthogonal to the front-back direction is defined as a lateral direction (Y). In the lateral direction, a direction heading to the slewing frame center line  11   a  is defined as a lateral inward direction (Y 1 ), and a direction going away from the slewing frame center line  11   a  is defined as a lateral outward direction (Y 2 ). As shown in  FIG. 2 , in an up-down direction (Z) (vertical direction), a direction heading from the lower travelling body  5  to the slewing frame  11  is defined as an upward direction (Z 1 ) and a reverse direction of the upward direction is defined as a downward direction (Z 2 ). 
     The pair of boom attaching portions  11   b  is a part to which the boom  20  is attached. The pair of boom attaching portions  11   b  protrudes upward from a base plate of the slewing frame  11 . An upper surface of each of the boom attaching portions  11   b  has a part slanting in the front-back direction so as to be located lower to the forward direction. As shown in  FIG. 1 , the pair of boom attaching portions  11   b  is provided at an interval in the lateral direction. The boom attaching portion  11   b  has, for example, a box-shaped structure (a structure having a hollow inside) or may have a plate-shaped structure. Each of the pair of boom attaching portions  11   b  has a circular pin hole H 11  (a first hole portion, a hole portion) formed (opened). A direction in which a central axis of the pin hole H 11  is parallel to the lateral direction (this is also the case with a pin hole H 20 ). The pin hole H 11  is arranged in an upper side and back side end portion of the boom attaching portion  11   b . “End portion” represents an end and a periphery thereof (the same hereafter). 
     The counter weight  13  is a weight fixed to a back side part of the slewing frame  11 . The cab  15  is a driver&#39;s cab in which an operator of the working machine  1  operates the working machine  1 . The guard  17  covers an equipment mounted on the slewing frame  11  and includes, for example, an engine guard covering an engine. An end portion of the guard  17  in the lateral outward direction (Y 2 ) is defined as a “vehicle width outermost part  17   s”.    
     The boom  20  (the second coupling body) is a member which lifts up a hung load via a rope (not shown) and is capable of going up and down with respect to the upper slewing body  10 . The boom  20  is attached to the slewing frame  11  via the coupling pin  30  in a raisable and lowerable manner. The boom  20  in a down state extends along the front-back direction. The boom  20  has, for example, a box-shaped structure and is designed to be extensible (a telescopic boom). The boom  20  has the pin hole H 20  (a second hole portion, a hole portion) formed (opened). The pin hole H 20  is located on the same axis as that of the pin hole H 11 . The pin hole H 20  is arranged in a back side end portion (base end portion) of the boom  20 . The back side end portion of the boom  20  is arranged between the pair of boom attaching portions  11   b  so as to be adjacent to the pair of boom attaching portions  11   b . The pin hole H 20  and the pin holes H 11  configure a pin hole H. 
     The coupling pin  30  is a pin to be attached or detached by the coupling pin attaching/detaching apparatus  40 . The coupling pin  30  is put into (attached to, inserted into) the pin hole H (the pin hole H 20  and the pin holes H 11 ). The coupling pin  30  couples the slewing frame  11  and the boom  20  so as to allow the boom  20  to be raised and lowered with respect to the slewing frame  11 . The coupling pin  30  is referred to also as a boom foot pin. As shown in  FIG. 3 , the coupling pin  30  includes a generally cylindrical coupling pin main body portion  31 , and a coupling pin side bracket  33 . A central axis and an extension line thereof of the coupling pin main body portion  31  in the coupling pin  30  are defined as a coupling pin central axis  30   a . Hereinafter, unless otherwise specified, description will be made of a case of a state where the pin hole H and the coupling pin  30  are coaxially arranged (e.g., a state where the coupling pin  30  is put into the pin hole H, and another state). 
     (Direction of Coupling Pin) 
     A direction in which the coupling pin central axis  30   a  extends is defined as a coupling pin axial direction (A) ( FIG. 3 ). In the present embodiment, the coupling pin axial direction is parallel to the lateral direction (Y). One direction in the coupling pin axial direction is defined as a coupling pin insertion direction (A 1 ), and a reverse direction of the coupling pin insertion direction is defined as a coupling pin extraction direction (A 2 ) ( FIG. 3 ). A radial direction of the coupling pin  30  is defined as a coupling pin radial direction (R) ( FIG. 3 ). The coupling pin radial direction is a diameter direction of a virtual circle on a plane orthogonal to the coupling pin central axis  30   a , the virtual circle being centered around the coupling pin central axis  30   a . In the coupling pin radial direction, a direction nearing to the coupling pin central axis  30   a  is defined as a coupling pin radial inward direction (R 1 ), and a direction going away from the coupling pin central axis  30   a  is defined as a coupling pin radial outward direction (R 2 ). 
     The coupling pin side bracket  33  is a member for connecting a connection member  80  (to be noted below) and the coupling pin  30 . The coupling pin side bracket  33  is fixed to the coupling pin main body portion  31 , and protrudes from an end portion (a right end portion) on a coupling pin extraction direction downstream side of the coupling pin main body portion  31  toward the coupling pin extraction direction (A 2 ) (a right direction). 
     As shown in  FIG. 1 , the coupling pin attaching/detaching apparatus  40  is a jig for attaching/detaching (extracting, putting into) the coupling pin  30  to/from the pin hole H. In the present embodiment, the coupling pin attaching/detaching apparatus  40  extracts the coupling pin  30  to the side opposite to the pin hole H 20  (to the side of the right pin hole H 11  out of the pair of pin holes H 11 ) in the axial direction. The coupling pin attaching/detaching apparatus  40  includes a fixing portion  41  (a jig fixing portion), a fixing side storage portion  45 , and an attaching/detaching apparatus  50 . 
     A position of the fixing portion  41  with respect to the pin hole H is fixed. The fixing portion  41  is a member (bracket) for supporting and fixing the attaching/detaching apparatus  50 . The fixing portion  41  is arranged in the vicinity of the pin hole H without blocking the pin hole H. The fixing portion  41  is fixed to a side surface (a right side surface) of the boom attaching portion  11   b  on the downstream side in the coupling pin extraction direction, and protrudes from the boom attaching portion  11   b  in the coupling pin extraction direction. As shown in  FIG. 4 , the fixing portion  41  includes two plate-shaped parts which sandwich, for example, the attaching/detaching apparatus  50  from upward and downward. As shown in  FIG. 8 , the fixing portion  41  includes a depressed portion  41   a  (for the depressed portion  41   a , see description of a connecting pin attaching/detaching opening portion  63 ). In  FIG. 3  and  FIG. 7 , illustration of the fixing portion  41  is omitted and an outline of the fixing portion  41  is shown by a chain double-dashed line. 
     As shown in  FIG. 1 , a position of the fixing side storage portion  45  with respect to the pin hole H is fixed. The fixing side storage portion  45  is a member (bracket) for fixing a frame  60  in a stored state (see  FIG. 8 ). The fixing side storage portion  45  is arranged outside the pin hole H in the coupling pin radial direction, for example, arranged ahead of the pin hole H. As shown in  FIG. 2 , the fixing side storage portion  45  is fixed to the boom attaching portion  11   b  and protrudes upward from the upper surface of the boom attaching portion  11   b . The fixing side storage portion  45  includes a rotation regulating portion  45   a . The rotation regulating portion  45   a  is a part which regulates rotation of the attaching/detaching apparatus  50  with respect to the fixing portion  41  (see  FIG. 8 ). 
     The attaching/detaching apparatus  50  (extraction apparatus) is an apparatus which attaches and detaches the coupling pin  30  as shown in  FIG. 1 . The attaching/detaching apparatus  50  includes the frame  60 , at least one cylinder  70 , and the connection member  80 . 
     The frame  60  supports the cylinder  70  and the connection member  80 . The frame  60  is attached to the slewing frame  11  so as to be opposed to the pin hole H 11  on the side opposite to the boom  20  in the axial direction of the coupling pin  30 . Additionally, the frame  60  defines a space portion which accepts the coupling pin  30  extracted from the pin hole H 11 . As shown in  FIG. 8 , the frame  60  is attached to the fixing portion  41  so as to be rotatable with a support pin P 1  as a rotation axis. A direction of the rotation axis of the frame  60  with respect to the fixing portion  41  is a direction orthogonal to the coupling pin axial direction, for example, parallel to the up-down direction. Rotation of the frame  60  with respect to the fixing portion  41  allows the frame  60  (the attaching/detaching apparatus  50 ) to be changed between a projected state (see  FIG. 3  and  FIG. 7 ) and the stored state (see  FIG. 8 ) as will be described in detail later. In the following, unless otherwise specified, the description will be made of a case where the frame  60  is in the projected state. As shown in  FIG. 3 , the frame  60  includes a frame main body portion  61 , a tubular portion  62 , the connecting pin attaching/detaching opening portion  63  (see  FIG. 7 ), a grip  64 , a cylinder tube fixing portion  65 , a cylinder tube supporting portion  66 , and a movable side storage portion  67 . 
     The frame main body portion  61  includes, for example, a generally box-shaped structure and includes, for example, a plurality of plate-shaped members. As shown in  FIG. 4 , the frame main body portion  61  includes an upper plate  61   a  configuring an upper surface of the frame main body portion  61 , a lower plate  61   b  configuring a lower surface of the frame main body portion  61 , and a pair of vertical plates  61   c . The pair of vertical plates  61   c  connects the upper plate  61   a  and the lower plate  61   b  and extends in the up-down direction. As shown in  FIG. 3 , the paired vertical plates  61   c  are disposed at an interval in the front-back direction. A large part of the vertical plate  61   c  extends along the coupling pin axial direction. An end portion of the vertical plate  61   c  on the downstream side in the coupling pin insertion direction slants with respect to the coupling pin axial direction so as to spread outward in the coupling pin radial direction (e.g., the front side or the back side). In  FIG. 3  and  FIG. 7 , a front part of the upper plate  61   a  than the coupling pin central axis  30   a  is omitted from illustration. Additionally, illustration of the grip  64  is similarly omitted. 
     The tubular portion  62  guides a guide portion  85  to be described later at the time of attaching or detaching the coupling pin  30  as shown in  FIG. 3 . The tubular portion  62  is arranged (formed) inside the frame main body portion  61 . The tubular portion  62  is formed of the upper plate  61   a , the lower plate  61   b , and the two vertical plates  61   c . The tubular portion  62  extends in the axial direction of the coupling pin  30 . As shown in  FIG. 5 , the tubular portion  62  is tubular, for example, square tubular. When viewed along the axial direction of the coupling pin  30 , the tubular portion  62  is, for example, square. The tubular portion  62  may be cylindrical or the like. 
     The connecting pin attaching/detaching opening portion  63  is opened for attaching and detaching a connecting pin P 5  as shown in  FIG. 3 . The connecting pin attaching/detaching opening portion  63  is formed in the frame main body portion  61 , and more specifically, formed in each of the upper plate  61   a  and the lower plate  61   b . The connecting pin attaching/detaching opening portion  63  is formed such that when the cylinder  70  is in a contracted state to be described later, the connecting pin P 5  can be inserted into the connecting pin attaching/detaching opening portion  63 . The connecting pin attaching/detaching opening portion  63  is a hole, which extends through the upper plate  61   a  and the lower plate  61   b  along the up-down direction. The connecting pin attaching/detaching opening portion  63  may not necessarily be a hole but a depressed part, and may be, for example, a partly depressed part of the end portion of the frame main body portion  61  on the downstream side in the coupling pin insertion direction, the part being depressed toward the coupling pin extraction direction. The fixing portion  41  includes the depressed portion  41   a  as shown in  FIG. 8  such that the connecting pin P 5  is inserted into the connecting pin attaching/detaching opening portion  63 . The depressed portion  41   a  is a partly depressed part of an end portion of the fixing portion  41  on the downstream side in the coupling pin extraction direction, the part being depressed toward the coupling pin insertion direction. 
     The grip  64  is a part held by a worker at the time of work for rotating the attaching/detaching apparatus  50  with respect to the fixing portion  41 . As shown in  FIG. 4 , the grip  64  protrudes from the frame main body portion  61 , for example, protrudes upward from the frame main body portion  61 . As shown in  FIG. 5 , in the present embodiment, the two grips  64  are provided at a front side part and a back side part of the frame main body portion  61 , respectively. 
     The cylinder tube fixing portion  65  is fixed to the frame main body portion  61  as shown in  FIG. 3 . An end portion of a cylinder tube  71  (described below) on the downstream side in the coupling pin extraction direction is fixed to the cylinder tube fixing portion  65 , for example. A force is transmitted to the cylinder tube fixing portion  65  along the axial direction of the coupling pin  30  from the cylinder tube  71 . 
     The cylinder tube supporting portion  66  is fixed to the frame main body portion  61  to support, for example, a front end side part of the cylinder tube  71  in the coupling pin insertion direction with respect to the frame main body portion  61 . 
     The movable side storage portion  67  is a part connected to the fixing side storage portion  45  and is fixed to the fixing side storage portion  45  when the frame  60  is in the stored state as shown in  FIG. 8 . Hereinafter, description will be made of a case where the frame  60  is in the projected state. As shown in  FIG. 3 , the movable side storage portion  67  is fixed to the frame main body portion  61 , fixed, for example, to the upper plate  61   a , the lower plate  61   b , and the vertical plate  61   c . The movable side storage portion  67  protrudes further ahead than the frame main body portion  61  and protrudes more to the front side than the cylinder  70 . 
     The cylinder  70  is arranged opposed to the space portion in the frame  60  in a direction orthogonal to the axial direction of the coupling pin  30  and is extensible. Extension of the cylinder  70  is controlled by a hydraulic system not shown of the working machine  1 . The cylinder  70  is a driving mechanism which attaches and detaches the coupling pin  30 . The cylinder  70  is attached to the frame  60 . A central axis of the cylinder  70 , which is a central axis extending in a longitudinal direction of the cylinder  70 , is defined as a cylinder central axis  70   a . The cylinder  70  is extensible along a direction in which the cylinder central axis  70   a  extends. In the present embodiment, a plurality of, for example, two cylinders  70  are provided. Each of the plurality of cylinders  70  includes the cylinder tube  71  (the cylinder fixed portion) and a cylinder rod  73  (the cylinder movable portion). The cylinder tube  71  is fixed to the frame main body portion  61 , and is fixed to each of the cylinder tube fixing portion  65  and the cylinder tube supporting portion  66 . The cylinder rod  73  is fit on the cylinder tube  71  so as to be movable with respect to the cylinder tube  71  along the cylinder central axis  70   a  direction. 
     The cylinder  70  is arranged outside the coupling pin  30  in the coupling pin radial direction. The cylinder central axis  70   a  is arranged outside the coupling pin central axis  30   a  in the coupling pin radial direction. Additionally, the cylinder  70  (at least a part thereof) is arranged outside a locus of the coupling pin  30  in the coupling pin radial direction at the time of attaching or detaching of the coupling pin  30 . 
     Additionally, the cylinder  70  may be arranged only outside the locus of the coupling pin  30  in the coupling pin radial direction at the time of attaching or detaching of the coupling pin  30 . For example, the cylinder  70  may be only arranged outside the tubular portion  62  in the coupling pin radial direction. 
     Additionally, an extension and contraction direction of the cylinder  70  may be parallel to the coupling pin axial direction (may be parallel to the coupling pin central axis  30   a ). 
     Hereinafter, as shown in  FIG. 5  and  FIG. 6 , description will be made of an arrangement of the cylinder  70  when viewed along the coupling pin axial direction. As shown in  FIG. 5 , when the two cylinders  70  are provided, a line segment linking the cylinder central axes  70   a  in front end portions (end portions in the coupling pin extraction direction) of the two cylinders  70  is defined as a line segment L. As shown in  FIG. 6 , when three or more cylinders  70  are provided, a polygon surrounded by line segments linking the cylinder central axes  70   a  in the front end portions of the cylinders  70  is defined as a polygon P. When the extension and contraction direction of the cylinder  70  is parallel to the coupling pin axial direction, the line segment L shown in  FIG. 5  can be said to be a line segment linking the cylinder central axes  70   a , and the polygon P shown in  FIG. 6  can be said to be a polygon surrounded by the line segments linking the cylinder central axes  70   a.    
     The plural cylinders  70  are arranged so as to sandwich the coupling pin  30  from the outer side in the coupling pin radial direction. More specifically, in a case where two cylinders  70  are provided, two (a pair of) cylinders  70  are arranged at both sides in the radial direction with the coupling pin  30  sandwiched therebetween when viewed from the axial direction of the coupling pin  30 , and at least a part of the coupling pin  30  is arranged on the line segment L as shown in  FIG. 5 . In other words, the two cylinders  70  are arranged on a straight line in the radial direction passing the central axis of the coupling pin  30  when viewed from the axial direction of the coupling pin  30 . Additionally, when three or more cylinders  70  are provided, at least a part of the coupling pin  30  is arranged within the polygon P as shown in  FIG. 6 . 
     When two cylinders  70  are provided, at least a part of the coupling pin  30  may be arranged at a middle point of the line segment L as shown in  FIG. 5 . When three or more cylinders  70  are provided, at least a part of the coupling pin  30  may be arranged at a centroid of the polygon P as shown in  FIG. 6 . 
     The plural cylinders  70  are arranged to be rotationally symmetric with respect to the coupling pin central axis  30   a  when viewed along the axial direction of the coupling pin. More specifically, when two cylinders  70  are provided, the cylinder central axes  70   a  in the front end portions of the cylinders  70  (both ends of the line segment L) are arranged to be point symmetric with respect to the coupling pin central axis  30   a  as shown in  FIG. 5 . When three or more cylinders  70  are provided, the cylinder central axes  70   a  in the front end portions of the cylinders  70  (corners of the polygon P) are arranged to be rotationally symmetric with respect to the coupling pin central axis  30   a  as shown in  FIG. 6 . 
     In the following, description will be made of a case where as shown in  FIG. 3  and  FIG. 7 , two cylinders  70  are arranged at an interval from each other in the front-back direction, and an extension and contraction direction of each of the cylinders  70  is parallel to the axial direction of the coupling pin. 
     The connection member  80  connects the coupling pin  30  and the cylinder  70  with each other such that in association with extension operation of the cylinder  70  due to relative movement of the cylinder rod  73 , the coupling pin  30  is extracted at least from the pin hole H 20  along the axial direction and is also guided into the space portion in the frame  60  ( FIG. 7 ). In the present embodiment, the connection member  80  is connected to the cylinder rod  73  of the cylinder  70 . The connection member  80  includes a first rod  81  (a first member), a second rod  82  (a second member), the guide portion  85 , and a connection member side bracket  87 . 
     The first rod  81  is a rod (a generally linear member, a bar-shaped member) connected to each cylinder rod  73  of the plurality of cylinders  70 . The first rod  81  is connected to a front end portion of the cylinder rod  73 . The first rod  81  extends in the front-back direction. 
     The second rod  82  is a rod which connects the first rod  81  and the coupling pin  30  with each other. The second rod  82  is connected to the first rod  81  between the front end portions of the plurality of (two) cylinder rods  73 . The second rod  82  is connected to the first rod  81  at a center part of the first rod  81  in a longitudinal direction. The second rod  82  is connected to the coupling pin  30  via the connection member side bracket  87 . The second rod  82  extends along the coupling pin axial direction and extends in the lateral direction. The second rod  82  (at least a part thereof) is arranged inside the tubular portion  62 . Shapes of the first rod  81  (the first member) and the second rod  82  (the second member) are not limited to the above. 
     The guide portion  85  guides movement of the connection member  80  with respect to the frame  60 . The guide portion  85  causes the connection member  80  to move with respect to the frame  60  along the coupling pin axial direction and regulates movement of the connection member  80  with respect to the frame  60  in the coupling pin radial direction. The guide portion  85  is fixed to the second rod  82 , for example, to a downstream side part of the second rod  82  in the coupling pin insertion direction (e.g., an end portion). The guide portion  85  is arranged inside the tubular portion  62  and is in contact with an inner surface of the tubular portion  62 . The guide portion  85  is slidable with respect to the tubular portion  62 . The guide portion  85  includes a pair of slide members  85 S arranged at a part in contact with the inner surface of the tubular portion  62  (see  FIG. 5 ). The pair of slide members  85 S is, for example, made of a resin, or, for example, a pad. 
     The connection member side bracket  87  is a member (bracket) for connecting the connection member  80  and the coupling pin  30 . The connection member side bracket  87  is connected (fixed) to the coupling pin side bracket  33  via the connecting pin P 5 . The connection member side bracket  87  is fixed to the end portion of the second rod  82  on the downstream side in the coupling pin insertion direction. 
     (Shape of Frame Main Body Portion  61 ) 
     A structure of the frame main body portion  61  is set according to arrangement of the cylinder  70  shown in  FIG. 3  or the like. The frame main body portion  61  is configured to be able to ensure a strength for supporting a force transmitted from the cylinder  70  (a force in the extension and contraction direction of the cylinder  70 ) and to be light-weighted. Specifically, in the frame main body portion  61 , a width, in the front-back direction (a width in the coupling pin radial direction) of the vicinity of the cylinder tube fixing portion  65 , is larger than a width, in the front-back direction, of a generally center part or the like of the frame main body portion  61  in the coupling pin axial direction. The width of the frame main body portion  61  in the front-back direction gradually increases from the generally center part of the frame main body portion  61  in the coupling pin axial direction toward the downstream side in the coupling pin extraction direction until reaching the vicinity of the cylinder tube fixing portion  65 . The upper plate  61   a  and the lower plate  61   b  of the frame main body portion  61  are arranged so as to sandwich the cylinder tube fixing portion  65  from upward and downward. 
     In the frame main body portion  61 , a width, in the front-back direction, of an end portion on the downstream side in the coupling pin insertion direction, is larger than the width, in the front-back direction, of the generally center part of the frame main body portion  61  in the coupling pin axial direction. This ensures an interval between the support pin P 1  and a fixing pin P 3  in the front-back direction. 
     In the frame main body portion  61 , compared with a width, in the front-back direction, of each of a downstream side part in the coupling pin insertion direction and a downstream side part in the coupling pin extraction direction, the width, in the front-back direction, of the generally center part of the frame main body portion  61  in the coupling pin axial direction, is small. This configuration enables the frame main body portion  61  to be light-weighted more than the frame main body portion  61  having a rectangular solid shape, for example. 
     (Details of Each Pin) 
     The support pin P 1  is a pin which connects the fixing portion  41  and the frame  60  so as to allow the frame  60  to be rotatable with respect to the fixing portion  41 . The support pin P 1  is put into a hole portion not shown which is opened, for example, in a front side part of each of the fixing portion  41  and the frame  60 . In particular, the support pin P 1  is put into a hole portion opened in an end portion of the frame  60  on the downstream side in the coupling pin insertion direction. A direction of a central axis of the support pin P 1  is parallel to the up-down direction. That the direction of the central axis is parallel to the up-down direction is also the case with the fixing pin P 3 , the connecting pin P 5 , a connection member fixing pin P 7 , and a storage pin P 9  (in another embodiment, a central axis of each pin may not necessarily be parallel to the up-down direction). 
     The fixing pin P 3  is a pin for fixing the frame  60  to the fixing portion  41 . The fixing pin P 3  is detachably attached with respect to the fixing portion  41  and the frame  60 . The fixing pin P 3  is put into a hole portion not shown which is opened, for example, in a back side part of each of the fixing portion  41  and the frame  60 . In particular, the fixing pin P 3  is put into the end portion of the frame  60  on the downstream side in the coupling pin insertion direction. The frame  60  is fixed to the slewing frame  11  via the fixing portion  41  by the fixing pin P 3 . 
     As shown in  FIG. 4 , the connecting pin P 5  is a pin (boom foot coupling pin) which connects the coupling pin  30  and the connection member  80 , and a pin which connects the coupling pin side bracket  33  and the connection member side bracket  87 . The connecting pin P 5  is, for example, a bolt or the like. 
     As shown in  FIG. 8 , the connection member fixing pin P 7  is a pin which fixes the connection member  80  to the frame  60 . The connection member fixing pin P 7  regulates extension and contraction of the cylinder  70  and fixes the cylinder  70  in the contracted state. The connection member fixing pin P 7  is detachably attached with respect to the frame  60  and the connection member  80 . As shown in  FIG. 3 , the connection member fixing pin P 7  is put into the hole portion not shown which is opened, for example, in an end portion of the frame  60  on the downstream side in the coupling pin extraction direction. Additionally, the connection member fixing pin P 7  is put into a hole portion not shown which is opened in an end portion of the connection member  80  on the downstream side (e.g., the second rod  82 ) in the coupling pin extraction direction. 
     The storage pin P 9  is a pin for fixing the frame  60  in the stored state as shown in  FIG. 8 . The storage pin P 9  is detachably attached with respect to the fixing side storage portion  45  and the movable side storage portion  67 . 
     (Operation of Coupling Pin Attaching/Detaching Apparatus  40 ) 
     The coupling pin attaching/detaching apparatus  40  operates in a manner below. The frame  60  is designed to have a state changeable (position changeable) between the projected state (see  FIG. 3  and  FIG. 7 ) and the stored state (see  FIG. 8 ). 
     (Projected State) 
     As shown in  FIG. 3  and  FIG. 7 , the projected state is a state of the frame  60  when the attaching/detaching apparatus  50  attaches and detaches the coupling pin  30 . The frame  60  in the projected state shown in  FIG. 3  is arranged to protrude from the pin hole H (the boom attaching portion  11   b  of the slewing frame  11 ) in the coupling pin axial direction and projects from the pin hole H outward in the lateral direction. At this time, the frame  60  is fixed to the slewing frame  11  via the fixing portion  41 , so that a position of the frame  60  with respect to the pin hole H is fixed. At this time, the fixing pin P 3  is put into the hole portion not shown which is opened in each of the fixing portion  41  and the frame  60 , thereby fixing the frame  60  to the fixing portion  41 . 
     (Coupling Pin Extraction Operation) 
     When the coupling pin  30  is extracted (at the time of extraction) in the state shown in  FIG. 3 , the coupling pin attaching/detaching apparatus  40  operates in the following manner. Extension of the cylinder  70  causes the coupling pin  30  to be extracted from the pin hole H via the connection member  80  (moved along the coupling pin extraction direction). Details of this operation are as follows. The cylinder rod  73  of each of the two cylinders  70  is moved with respect to the cylinder tube  71  in the coupling pin extraction direction. As a result, the cylinder rod  73  causes the connection member  80  to move in the coupling pin extraction direction. At this time, the guide portion  85  slides on the inner surface of the tubular portion  62  to move in the coupling pin extraction direction, thereby guiding movement of the second rod  82 . The second rod  82  causes the coupling pin  30  to move in the coupling pin extraction direction via the connection member side bracket  87 . As shown in  FIG. 7 , when the cylinder  70  extends to a predetermined length, the coupling pin  30  is extracted from the pin hole H 20  of the boom  20 . As a result, the boom  20  is brought into a state of being separable from the slewing frame  11 . In this state, the cylinder  70  finishes extending. At this time, the cylinder  70  enters an extended state (e.g., a most extended). 
     When the cylinder  70  is in the extended state, at least a part of the coupling pin  30  is arranged on the side more downstream in the coupling pin extraction direction than an end portion of the cylinder  70  on the downstream side in the coupling pin insertion direction. At this time, at least a part of the coupling pin  30  is sandwiched between the two cylinders  70  in the front-back direction. At this time, a large part of the coupling pin  30  is arranged inside the tubular portion  62 . 
     (Coupling Pin Insertion Operation) 
     When the coupling pin  30  is put into the hole in the state shown in  FIG. 7  (at the time of insertion), the coupling pin attaching/detaching apparatus  40  conducts reverse operation to that conducted at the time of extraction. The operation is outlined as follows. Contraction of the cylinder  70  causes the coupling pin  30  to be put into the pin hole H via the connection member  80  (moved in the coupling pin insertion direction). As a result, the coupling pin  30  is put into the pin hole H 11  of the slewing frame  11  (the boom attaching portion  11   b ) and the pin hole H 20  of the boom  20  as shown in  FIG. 3 . As a result, the slewing frame  11  and the boom  20  are connected. In this state, contraction of the cylinder  70  ends. At this time, the cylinder  70  enters the contracted state (e.g., a most contracted state). 
     (Stored State) 
     As shown in  FIG. 8 , the stored state of the attaching/detaching apparatus  50  is a state where attaching/detaching operation of the coupling pin  30  is not executed and a state where the frame  60  is stored. A longitudinal direction of the frame  60  in the stored state is a direction different from the coupling pin axial direction, and is specifically a direction orthogonal to the coupling pin axial direction and is parallel to the front-back direction. 
     Operation of the coupling pin attaching/detaching apparatus  40  is as follows when the state of the frame  60  changes from the projected state (see  FIG. 3 ) to the stored state (see  FIG. 8 ). In the following, description will be made following procedures of work for changing the projected state to the stored state (procedures may be appropriately changed). The connecting pin P 5  shown in  FIG. 3  is removed from the coupling pin side bracket  33  and the connection member side bracket  87 . Next, the coupling pin  30  is removed from the connection member  80 . Next, the cylinder  70  is brought into the contracted state. Next, the connection member fixing pin P 7  is put into the hole portions of the frame  60  and the connection member  80 . As a result, the frame  60  and the connection member  80  are fixed, so that the cylinder  70  is fixed in the contracted state. The connection member fixing pin P 7  is used also as the fixing pin P 3  (in another embodiment, the connection member fixing pin P 7  may not necessarily be used also as the fixing pin P 3 ). 
     The fixing pin P 3  is removed from the fixing portion  41  and the frame  60 . Next, as shown in  FIG. 8 , the attaching/detaching apparatus  50  is rotated with respect to the fixing portion  41 , with the support pin P 1  as a center of rotation. At this time, the attaching/detaching apparatus  50  rotates such that an end portion of the attaching/detaching apparatus  50  on the downstream side in the coupling pin extraction direction moves forward. When the attaching/detaching apparatus  50  rotates, the movable side storage portion  67  comes into contact with the rotation regulating portion  45   a  of the fixing side storage portion  45 . As a result, rotation of the attaching/detaching apparatus  50  is regulated. Next, the storage pin P 9  is put into hole portions of the fixing side storage portion  45  and the movable side storage portion  67 , so that the movable side storage portion  67  and the fixing side storage portion  45  are fixed. As a result, the frame  60  is fixed with respect to the slewing frame  11  (to the pin hole H). This state of the frame  60  is the stored state. The storage pin P 9  is used also as the connecting pin P 5  (in another embodiment, the storage pin P 9  may not necessarily be used also as the connecting pin P 5 ). 
     As described in the foregoing, in the present embodiment, the frame  60  is attached to the slewing frame  11  to be rotatable around the rotation axis extending in a direction orthogonal to the axial direction of the coupling pin  30 , so that the frame  60  is allowed to change a posture thereof along with rotation around the rotation axis between a projected posture of projecting from the slewing frame  11  in the axial direction by a predetermined amount of projection, the projected posture being a posture where the space portion in the frame  60  accepts the coupling pin  30 , and a stored posture of projecting from the slewing frame  11  in the axial direction by an amount of projection smaller than that of the projected posture. 
     (Problem of Structure for Pushing out Coupling Pin) 
     Consideration will be given to another jig having a structure in which with the cylinder  70  and the coupling pin  30  coaxially arranged, extension of the cylinder  70  causes the cylinder  70  to push out the coupling pin  30  from the pin hole H (as Comparative Example 1). In this jig of the Comparative Example 1, when the coupling pin  30  is pushed out from the pin hole H, the cylinder rod  73  remains in the pin hole H (boss). Therefore, for example, when the upper slewing body  10  or the boom  20  moves, the cylinder rod  73  might come into contact with the pin hole H to damage the cylinder rod  73 . 
     (Problem of Structure with Coaxially Arranged Cylinder and Coupling Pin) 
     Additionally, consideration will be given to another jig having a structure in which with the cylinder  70  and the coupling pin  30  coaxially arranged, contraction of the cylinder  70  causes the cylinder  70  to extract the coupling pin  30  from the pin hole H (as Comparative Example 2). The structure of this Comparative Example 2 mitigates the above problem of Comparative Example 1. However, there remains a need of ensuring a “draught” of the coupling pin  30 . More specifically, since in Comparative Example 2, the cylinder  70  is coaxially arranged with the coupling pin  30 , the cylinder  70  in the contracted state should be arranged on the side more downstream in the coupling pin extraction direction than the extracted coupling pin  30 . Therefore, as compared with the present embodiment, a length of a jig (a length of a configuration, an entire length) in the coupling pin axial direction might be increased. 
     (Problem of Protrusion from Vehicle Width Outermost Part  17   s ) 
     When the jig is long in the lateral direction as in Comparative Example 2, the jig might largely protrude from the vehicle width outermost part  17   s  (see  FIG. 1 ) in the lateral outward direction (more largely than in the present embodiment). Therefore, the jig might become a hindrance during working of the working machine  1  (in particular, during working in a narrow space) or during transportation of the working machine  1 . By way of prevention, the attaching/detaching apparatus  50  may be attached to the upper slewing body  10  during assembly and disassembly of the working machine  1  (at the time of attachment and detachment of the coupling pin  30 ) and the attaching/detaching apparatus  50  may be removed from the upper slewing body  10  during working and transportation of the working machine  1 . However, attachment or detachment of the attaching/detaching apparatus  50  to or from the upper slewing body  10  takes time for working. Additionally, at the time of transportation of the upper slowing body  10 , the attaching/detaching apparatus  50  should be transported separately from the upper slewing body  10 . Therefore, it takes time for working for transporting the attaching/detaching apparatus  50 . Additionally, a transportation apparatus is required for transporting the attaching/detaching apparatus  50 . Ensuring a space for using the transportation apparatus therefore might make a working space for the working machine  1  be narrow. By contrast, the coupling pin attaching/detaching apparatus  40  of the present embodiment enables mitigation of the above problems as described in the following. The coupling pin attaching/detaching apparatus  40  of the present embodiment may enable only a part of the above-described problems to be mitigated. 
     Effects obtained by the coupling pin attaching/detaching apparatus  40  shown in  FIG. 1  are as follows. The coupling pin attaching/detaching apparatus  40  is provided in the working machine  1 . The working machine  1  includes the slewing frame  11 , the boom  20 , and the coupling pin  30 . The coupling pin  30  is inserted into the pin hole H of the slewing frame  11  and the boom  20  to couple the slewing frame  11  and the boom  20 . The coupling pin attaching/detaching apparatus  40  includes the cylinder  70  and the connection member  80 . 
     The cylinder  70  is arranged outside the coupling pin  30  in the radial direction of the coupling pin and is extensible. The connection member  80  is connected to the coupling pin  30  and the cylinder  70 . Extension of the cylinder  70  causes the coupling pin  30  to be extracted from the pin hole H via the connection member  80 . 
     In such a configuration, when the coupling pin  30  is extracted, it is unnecessary to arrange (leave) the components of the coupling pin attaching/detaching apparatus  40  (e.g., the cylinder rod  73 , the second rod  82  and the like shown in  FIG. 3 ) inside the pin hole H. Thus, when the coupling pin  30  shown in  FIG. 1  is removed from the pin hole H, the components of the coupling pin attaching/detaching apparatus  40  are suppressed from coming into contact with the pin hole H. As a result, the coupling pin attaching/detaching apparatus  40  is suppressed from being damaged. 
     Additionally, as shown in  FIG. 7 , since the cylinder  70  is arranged outside the coupling pin  30  in the radial direction of the coupling pin, at least a part of the cylinder  70  can be arranged on the more downstream side in the coupling pin insertion direction than an end portion of the extracted coupling pin  30  on the downstream side in the coupling pin extraction direction. Therefore, compared with a case where such arrangement is not allowed (e.g., in the above Comparative Example 2 or the like), the length of the coupling pin attaching/detaching apparatus  40  in the coupling pin axial direction shown in  FIG. 3  can be held down. 
     The “length of the coupling pin attaching/detaching apparatus  40  in the coupling pin axial direction” is a length in the coupling pin axial direction from the pin hole H to an end portion of the coupling pin attaching/detaching apparatus  40  on the downstream side in the coupling pin extraction direction. Additionally, this length is a length when the cylinder  70  is in the contracted state. Additionally, this length is a length when the frame  60  is in the projected state in the present embodiment. 
     Additionally, in the present embodiment, a plurality of cylinders  70  is provided. Therefore, compared with a case where only one cylinder  70  is provided, each cylinder  70  can be reduced in size. 
     Additionally, in the present embodiment, as shown in  FIG. 5 , the plural cylinders  70  are arranged so as to sandwich the coupling pin  30  from the outer side in the coupling pin radial direction when viewed along the coupling pin axial direction. Therefore, a bending force generated in the connection member  80  can be suppressed. As a result, the connection member  80  can be reduced in size and weight to realize a simple configuration. 
     The plurality of cylinders  70  is arranged to be rotationally symmetric with respect to the coupling pin central axis  30   a  when viewed along the coupling pin axial direction. This enables further suppression of the bending force generated in the connection member  80 . As a result, the connection member  80  can be further reduced in size and weight to realize a simple configuration. 
     Additionally, in the present embodiment, the connection member  80  includes the first rod  81  connected to each of the plurality of cylinders  70 , and the second rod  82  connected to the first rod  81  and the coupling pin  30  as shown in  FIG. 3 . Thus, the connection member  80  can be simply configured. 
     Further, in the present embodiment, a direction of extension and contraction of the cylinder  70  is a direction parallel to the coupling pin central axis  30   a . Thus, it is not necessary to provide a mechanism for converting operation of the cylinder  70  in the extension and contraction direction to operation in the coupling pin axial direction. Thus, the connection member  80  can be reduced in size and weight to realize a simple configuration. 
     Further, in the present embodiment, a direction in which the coupling pin central axis  30   a  extends (the coupling pin axial direction) is a direction orthogonal to a longitudinal direction of the upper slewing body  10  of the working machine  1  and a direction extending in the horizontal direction (the lateral direction) as shown in  FIG. 1 . In the present embodiment, the cylinder  70  is arranged outside the coupling pin  30  in the radial direction of the coupling pin. Thus, the length of the coupling pin attaching/detaching apparatus  40  in the coupling pin axial direction is reduced. Further, since as described above, the coupling pin axial direction extends along the direction orthogonal to the longitudinal direction of the upper slewing body  10 , the length of the coupling pin attaching/detaching apparatus  40  in the lateral direction is reduced. Therefore, for example, an amount of protrusion (an amount of projection) of the coupling pin attaching/detaching apparatus  40  from an end portion of the upper slewing body  10  (the vehicle width outermost part  17   s ) in the lateral outward direction is suppressed, or alternatively, the amount of protrusion can be eliminated. As a result, during working and transportation of the working machine  1 , the part of the coupling pin attaching/detaching apparatus  40  protruding from the vehicle width outermost part  17   s  can be suppressed from becoming a hindrance. 
     Additionally, in the present embodiment, the coupling pin attaching/detaching apparatus  40  includes the fixing portion  41  and the frame  60  as shown in  FIG. 8 . A position of the fixing portion  41  is fixed with respect to the pin hole H. Additionally, the frame  60  is attached to the fixing portion  41  so as to be rotatable with a direction orthogonal to the coupling pin axial direction as a rotation axis, thereby supporting the cylinder  70  and the connection member  80 . In this case, rotation of the frame  60  with respect to the fixing portion  41  enables the coupling pin attaching/detaching apparatus  40  to have a variable length in the coupling pin axial direction. For example, rotation of the frame  60  with respect to the fixing portion  41  enables reduction in the length of the coupling pin attaching/detaching apparatus  40  in the coupling pin axial direction to allow storage of the coupling pin attaching/detaching apparatus  40 . 
     Further, in the present embodiment, the coupling pin attaching/detaching apparatus  40  includes the fixing pin P 3  as shown in  FIG. 3 . The fixing pin P 3  is attachable to or detachable from the fixing portion  41  and the frame  60 , and enables the frame  60  to be fixed to the fixing portion  41 . In this case, attachment/detachment of the fixing pin P 3  enables switching with ease between a state where the frame  60  is fixed to the fixing portion  41  and a state where the frame  60  is rotatable with respect to the fixing portion  41 . As a result, switching can be easily made between a state of the frame  60  (the projected state) when the coupling pin  30  is attached/detached, and a state, as shown in  FIG. 8 , where the frame  60  is stored (the stored state) without attachment/detachment of the coupling pin  30 . For example, the switching is possible without using a tool or a jig. 
     Further, in the present embodiment, the direction in which the coupling pin central axis  30   a  extends is parallel to the horizontal direction (the lateral direction) orthogonal to the longitudinal direction of the upper slewing body  10  of the working machine  1  as shown in  FIG. 1 . As described above, the frame  60  is attached to the fixing portion  41  so as to be rotatable with the direction orthogonal to the coupling pin axial direction as a rotation axis, thereby supporting the cylinder  70  and the connection member  80 . In this case, as shown in  FIG. 8 , rotation of the frame  60  with respect to the fixing portion  41  enables the coupling pin attaching/detaching apparatus  40  to have a variable length in the coupling pin axial direction. Further, since the direction in which the coupling pin central axis  30   a  extends is the horizontal direction orthogonal to the longitudinal direction of the upper slowing body  10  of the working machine  1 , the above rotation of the frame  60  enables the coupling pin attaching/detaching apparatus  40  to have a variable length in the lateral direction. For example, the above rotation of the frame  60  enables reduction in the length of the coupling pin attaching/detaching apparatus  40  in the lateral direction. 
     Specifically, for example, there is a case where when the frame  60  is in the projected state, the coupling pin attaching/detaching apparatus  40  protrudes from the vehicle width outermost part  17   s  in the lateral outward direction as shown in  FIG. 1 . Even in this case, rotation of the frame  60  with respect to the fixing portion  41  enables arrangement of the coupling pin attaching/detaching apparatus  40  only inside the vehicle width outermost part  17   s  in the lateral direction. It is therefore possible to mitigate the “Problem of Protrusion from Vehicle Width Direction Outermost Part  17   s”.    
     Further, in the present embodiment, the first coupling body is the slewing frame  11  configuring the main body portion (the upper slewing body  10 ) of the working machine  1 . The second coupling body is the boom  20  attached to the slewing frame  11  via the coupling pin  30  in a raisable and lowerable manner. The coupling pin  30  is a boom foot pin inserted into the pin hole H 20  formed at the base end portion (the end portion on the back side) of the boom  20 . 
     In this case, the coupling pin attaching/detaching apparatus  40  is used for extracting the boom foot pin of a crane. The boom foot pin is larger than another pin (e.g., the support pin P 1  in  FIG. 3  or the like), so that the pin cannot be extracted manually. Therefore, use of the coupling pin attaching/detaching apparatus  40  easily facilitates extraction of the coupling pin  30  as the boom foot pin. 
     As described in the foregoing, in the present embodiment, the working machine  1  includes the upper slewing body  10  including the stewing frame  11 , the boom  20  attached to the slewing frame  11  to be able to be raised and lowered, the boom foot pin which couples the slewing frame  11  and the boom  20  so as to enable the boom  20  to be raised and lowered, and the coupling pin attaching/detaching apparatus  40 . The first coupling body according to the present invention includes the slewing frame  11 , the second coupling body includes the boom  20 , and the coupling pin includes the boom foot pin. The boom foot pin is designed to be inserted into the pin hole H 11  opened in the slewing frame  11  and into the pin hole H 20  opened in the base end portion of the boom  20 . The coupling pin attaching/detaching apparatus  40  extracts the boom foot pin at least from the pin hole H 20 . 
     Modified Embodiment 
     Although the members (the first coupling body and the second coupling body) coupled by the coupling pin  30  in the above embodiment are the slewing frame  11  and the boom  20 , either one or both of these may be changed. The coupling pin  30 , which is the boom foot pin in the above embodiment, may be another pin. The coupling pin  30 , which is arranged in a back side part of the boom attaching portion  11   b  in the above embodiment, may be arranged in, for example, an end portion on the front side of the slewing frame  11 . The boom  20 , which is an extensible boom in the above embodiment, may be a latticed boom. 
     The coupling pin attaching/detaching apparatus  40  is used for extracting the coupling pin  30 , and may not necessarily be used for putting the coupling pin  30  into the pin hole H. 
     The arrangement and the operation directions in the above embodiment may be changed. For example, the coupling pin axial direction, which is the lateral direction in the above embodiment, may be the front-back direction or the up-down direction, or a direction slanting to these directions. For example, although when the working machine  1  is viewed from the back side toward the front side, the coupling pin attaching/detaching apparatus  40  is arranged further on the right side than the boom attaching portion  11   b  in  FIG. 1 , the coupling pin attaching/detaching apparatus  40  may be arranged further on the left side than the boom attaching portion  11   b . For example, although a direction in which the rotation axis of the attaching/detaching apparatus  50  with respect to the fixing portion  41  extends is the up-down direction in the above embodiment, the direction may be the horizontal direction or a direction slanting to these directions. Although the direction of the rotation for changing the attaching/detaching apparatus  50  from the projected state to the stored state is counterclockwise when viewed from above in the example shown in  FIG. 8 , the direction may be clockwise. Although the extension and contraction direction of the cylinder  70  shown in  FIG. 7  is parallel to the coupling pin axial direction in the above embodiment, the direction may slant to the coupling pin axial direction or may be orthogonal to the coupling pin axial direction. When the extension and contraction direction of the cylinder  70  and the coupling pin axial direction are different from each other (cross with each other), a mechanism is preferably provided which converts movement of the cylinder  70  in the extension and contraction direction into movement in the coupling pin axial direction. 
     A part of the components of the above embodiment may not necessarily be provided. For example, such a configuration as shown in  FIG. 8 , in which the frame  60  is rotatable with respect to the fixing portion  41 , may not necessarily be provided. For example, the position of the frame  60  may be constantly fixed with respect to the pin hole H. 
     Fixing or connection may be made directly or indirectly. For example, the frame  60 , which is fixed to the slewing frame  11  via the fixing portion  41  in the above embodiment, may be directly fixed to the slewing frame  11 . For example, the fixing portion  41 , which is separate from the slewing frame  11  in the example shown in  FIG. 4 , may be configured integrally with the slewing frame  11 . 
     The number of components in the above embodiment may be changed. For example, although two cylinders  70  are provided in the present embodiment and four cylinders  70  are provided in  FIG. 6 , only one, or three, or five or more cylinders may be provided. Of the cylinder tube  71  and the cylinder rod  73  shown in  FIG. 7 , the member fixed to the frame  60 , which is the cylinder tube  71  in the above embodiment, may be the cylinder rod  73 . 
     The shapes of the components in the above embodiment may be changed. For example, the connection member  80  may not necessarily be provided with such rods as the first rod  81  and the second rod  82 . 
     A detachable pin such as the fixing pin P 3  may not necessarily be attached or detached manually, but may be attached or detached using a tool or a jig. 
     This application is based on Japanese Patent application No. 2016-121131 filed in Japan Patent Office on Jun. 17, 2016, the contents of which are hereby incorporated by reference. 
     Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be understood that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention hereinafter defined, they should be construed as being included therein.