Patent Publication Number: US-2021189689-A1

Title: Shovel

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application filed under 35 U.S.C. 111(a) claiming benefit under 35 U.S.C. 120 and 365(c) of PCT International Application No. PCT/JP2019/029671, filed on Jul. 29, 2019 and designating the U.S., which claims priority to Japanese patent application No. 2018-144609, filed on Jul. 31, 2018. The entire contents of the foregoing applications are incorporated herein by reference. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to shovels. 
     Description of Related Art 
     A shovel with adjustably positionable console boxes provided one on each side of an operator seat has been known. Operating levers are provided on the front of the console boxes provided one on each side of the operator seat. An operator can adjust the positions of the operating levers by tilting or vertically adjusting the positions of the console boxes. 
     SUMMARY 
     According to an aspect of the present invention, a shovel includes an upper swing structure, a cab mounted on the upper swing structure, and an operating lever provided in the cab. The operating lever includes a lever part to which a grip part is fixed, a holder part to which the lever part is connected, and a joint part connecting the lever part and the holder part. The lever part is configured to be attachable to and detachable from the holder part in a tool-free manner with a predetermined manual operation on the joint part. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a shovel according to an embodiment of the present invention; 
         FIG. 2  is a diagram illustrating an example configuration of a hydraulic system installed in the shovel; 
         FIG. 3  is a perspective view of an operator seat unit provided in a cabin of the shovel; 
         FIG. 4  is a perspective view of the inside of the cabin; 
         FIG. 5  is a side view of a left operating lever; 
         FIGS. 6A and 6B  are a perspective view and a sectional view, respectively, of a spigot joint structure; 
         FIGS. 7A and 7B  are a perspective view and a sectional view, respectively, of an example configuration of a lever part, a joint part, and a holder part; 
         FIGS. 8A and 8B  are a perspective view and a sectional view, respectively, of another example configuration of the lever part, the joint part, and the holder part; 
         FIG. 8C  is a diagram illustrating a cross section perpendicular to an axis including a one-dot chain line of  FIG. 8B ; 
         FIGS. 9A and 9B  are a perspective view and a sectional view, respectively, of yet another example configuration of the lever part, the joint part, and the holder part; 
         FIGS. 10A and 10B  are a perspective view and a sectional view, respectively, of still another example configuration of the lever part, the joint part, and the holder part; 
         FIGS. 11A and 11B  are a perspective view and a sectional view, respectively, of yet still another example configuration of the lever part, the joint part, and the holder part; 
         FIG. 11C  is a diagram illustrating a cross section perpendicular to the axis including a one-dot chain line of  FIG. 11B ; 
         FIGS. 12A and 12B  are a perspective view and a sectional view, respectively, of even another example configuration of the lever part, the joint part, and the holder part; 
         FIG. 12C  is a perspective view of a rotary wedge that is a component of the joint part and a recess of the lever part in which the rotary wedge fits; 
         FIG. 13A  is a perspective view of yet even another example configuration of the lever part, the joint part, and the holder part; 
         FIG. 13B  is a diagram illustrating a cross section perpendicular to the axis including a one-dot chain line of  FIG. 13A ; 
         FIGS. 14A and 14B  are perspective views of still even another example configuration of the lever part, the joint part, and the holder part; and 
         FIG. 15  is a diagram illustrating an example configuration of an electric operation system. 
     
    
    
     DETAILED DESCRIPTION 
     The operator of the related-art shovel, however, may be unable to adjust the positions of the operating levers to optimal positions by only adjusting the positions of the console boxes. 
     Therefore, it is desired to provide a shovel with operating levers whose positions are more flexibly adjustable. 
     According to an aspect of the present invention, it is possible to provide a shovel with operating levers whose positions are more flexibly adjustable. 
     First, a shovel  100  serving as an excavator according to an embodiment of the present invention is, described with reference to  FIG. 1 .  FIG. 1  is a side view of a shovel  100 . 
     According to this embodiment, a lower traveling structure  1  of the shovel  100  includes a crawler  10 . The crawler  10  is driven by travel hydraulic motors  2 M mounted in the lower traveling structure  1 . The travel hydraulic motors  2 M may be replaced with travel motor generators serving as electric actuators. Specifically, the crawler  10  includes a left crawler and a right crawler. The left crawler is driven by a left travel hydraulic motor  2 ML (see  FIG. 2 ) and the right crawler is driven by a right travel hydraulic motor  2 MR (see  FIG. 2 ). 
     An upper swing structure  3  is swingably mounted on the lower traveling structure  1  via a swing mechanism  2 . The swing mechanism  2  is driven by a swing hydraulic motor  2 A mounted on the upper swing structure  3 . The swing hydraulic motor  2 A, however, may be replaced with a swing motor generator serving as an electric actuator. 
     A boom  4  is attached to the upper swing structure  3 . An arm  5  is attached to the distal end of the boom  4 . A bucket  6  serving as an end attachment is attached to the distal end of the arm  5 . The boom  4 , the arm  5 , and the bucket  6  constitute an excavation attachment that is an example of an attachment. The boom  4  is driven by a boom cylinder  7 . The arm  5  is driven by an arm cylinder  8 . The bucket  6  is driven by a bucket cylinder  9 . 
     A cabin  10  serving as a cab is provided and a power source such as an engine  11  is mounted on the upper swing structure  3 . An operating device  26 , a controller  30 , etc., are provided in the cabin  10 . In this specification, for convenience, the side of the upper swing structure  3  on which the boom  4  is attached is defined as the front side and the side of the upper swing structure  3  on which a counterweight is attached is defined as the back side. 
     The controller  30  is a control device for controlling the shovel  100 . According to this embodiment, the controller  30  is constituted of a processor unit including a CPU, a volatile storage, and a nonvolatile storage. The controller  30  reads programs corresponding to functional elements from the nonvolatile storage, loads the programs into the volatile storage, and causes the CPU to execute corresponding processes. 
     Next, an example configuration of a hydraulic system installed in the shovel  100  is described with reference to  FIG. 2 .  FIG. 2  is a diagram illustrating an example configuration of the hydraulic system installed in the shovel  100 . In  FIG. 2 , a mechanical power transmission line, a hydraulic oil line, a pilot line, and an electrical control line are indicated by a double line, a solid line, a dashed line, and a dotted line, respectively. 
     The hydraulic system of the shovel  100  mainly includes the engine  11 , a regulator  13 , a main pump  14 , a pilot pump  15 , a control valve unit  17 , the operating device  26 , a discharge pressure sensor  28 , an operating pressure sensor  29 , the controller  30 , and a control valve  60 . 
     In  FIG. 2 , the hydraulic system circulates hydraulic oil from the main pump  14  driven by the engine  11  to a hydraulic oil tank via a center bypass conduit  40  or a parallel conduit  42 . 
     The engine  11  is a power source for the shovel  100 . According to this embodiment, the engine  11  is, for example, a diesel engine that operates in such a manner as to maintain a predetermined rotational speed. The output shaft of the engine  11  is connected to the input shaft of each of the main pump  14  and the pilot pump  15 . 
     The main pump  14  is configured to supply hydraulic oil to the control valve unit  17  via a hydraulic oil line. According to this embodiment, the main pump  14  is a swash plate variable displacement hydraulic pump. 
     The regulator  13  is configured to control the discharge quantity of the main pump  14 . According to this embodiment, the regulator  13  controls the discharge quantity of the main pump  14  by adjusting the swash plate tilt angle of the main pump  14  in response to a control command from the controller  30 . 
     The pilot pump  15  is configured to supply hydraulic oil to hydraulic control devices including the operating device  26  via a pilot line. According to this embodiment, the pilot pump  15  is a fixed displacement hydraulic pump. The pilot pump  15 , however, may be omitted. In this case, the function carried by the pilot pump  15  may be implemented by the main pump  14 . That is, the main pump  14  may have the function of supplying hydraulic oil to the operating device  26 , etc., after reducing the pressure of the hydraulic oil with a throttle or the like, apart from the function of supplying hydraulic oil to the control valve unit  17 . 
     The control valve unit  17  is configured to accommodate multiple control valves such that the control valves are operable. According to this embodiment, the control valve unit  17  includes control valves  171  through  176 . The control valve  175  includes a control valve  175 L and a control valve  175 R. The control valve  176  includes a control valve  176 L and a control valve  176 R. The control valve unit  17  can selectively supply hydraulic oil discharged by the main pump  14  to one or more hydraulic actuators through the control valves  171  through  176 . The control valves  171  through  176  control the flow rate of hydraulic oil flowing from the main pump  14  to the hydraulic actuators and the flow rate of hydraulic oil flowing from the hydraulic actuators to the hydraulic oil tank. The hydraulic actuators include the boom cylinder  7 , the arm cylinder  8 , the bucket cylinder  9 , the left travel hydraulic motor  2 ML, the right travel hydraulic motor  2 MR, and the swing hydraulic motor  2 A. 
     The operating device  26  is a device that the operator uses to operate actuators. The actuators include at least one of a hydraulic actuator and an electric actuator. According to this embodiment, the operating device  26  is configured to supply hydraulic oil discharged by the pilot pump  15  to a pilot port of a corresponding control valve in the control valve unit  17  via a pilot line. The pressure of hydraulic oil supplied to each pilot port (control pressure) is a pressure commensurate with the direction of operation and the amount of operation of a lever or a pedal (not depicted) of the operating device  26  corresponding to each hydraulic actuator. 
     The discharge pressure sensor  28  is configured to detect the discharge pressure of the main pump  14 . According to this embodiment, the discharge pressure sensor  28  outputs a detected value to the controller  30 . 
     The operating pressure sensor  29  is configured to detect the details of the operator&#39;s operation of the operating device  26 . According to this embodiment, the operating pressure sensor  29  detects the direction of operation and the amount of operation of a lever or a pedal of the operating device  26  corresponding to each actuator in the form of pressure (operating pressure), and outputs the detected value to the controller  30 . The operation details of the operating device  26  may also be detected using a sensor other than an operating pressure sensor. 
     The main pump  14  includes a left main pump  14 L and a right main pump  14 R. The left main pump  14 L circulates hydraulic oil to the hydraulic oil tank via at least one of a left center bypass conduit  40 L and a left parallel conduit  42 L. The right main pump  14 R circulates hydraulic oil to the hydraulic oil tank via at least one of a right center bypass conduit  40 R and a right parallel conduit  42 R. 
     The left center bypass conduit  40 L is a hydraulic oil line that passes through the control valves  171 ,  173 ,  175 L, and  176 L placed in the control valve unit  17 . The right center bypass conduit  40 R is a hydraulic oil line that passes through the control valves  172 ,  174 ,  175 R, and  176 R placed in the control valve unit  17 . 
     The control valve  171  is a spool valve that switches the flow of hydraulic oil so that hydraulic oil discharged by the left main pump  14 L can be supplied to the left travel hydraulic motor  2 ML and that hydraulic oil discharged by the left travel hydraulic motor  2 ML can be discharged to the hydraulic oil tank. 
     The control valve  172  is a spool valve that switches the flow of hydraulic oil so that hydraulic oil discharged by the right main pump  14 R can be supplied to the right travel hydraulic motor  2 MR and that hydraulic oil discharged by the right travel hydraulic motor  2 MR can be discharged to the hydraulic oil tank. 
     The control valve  173  is a spool valve that switches the flow of hydraulic oil so that hydraulic oil discharged by the left main pump  14 L can be supplied to the swing hydraulic motor  2 A and that hydraulic oil discharged by the swing hydraulic motor  2 A can be discharged to the hydraulic oil tank. 
     The control valve  174  is a spool valve that switches the flow of hydraulic oil so that hydraulic oil discharged by the right main pump  14 R can be supplied to the bucket cylinder  9  and that hydraulic oil in the bucket cylinder  9  can be discharged to the hydraulic oil tank. 
     The control valve  175 L is a spool valve that switches the flow of hydraulic oil so that hydraulic oil discharged by the left main pump  14 L can be supplied to the boom cylinder  7 . The control valve  175 R is a spool valve that switches the flow of hydraulic oil so that hydraulic oil discharged by the right main pump  14 R can be supplied to the boom cylinder  7  and that hydraulic oil in the boom cylinder  7  can be discharged to the hydraulic oil tank. 
     The control valve  176 L is a spool valve that switches the flow of hydraulic oil so that hydraulic oil discharged by the left main pump  14 L can be supplied to the arm cylinder  8  and that hydraulic oil in the arm cylinder  8  can be discharged to the hydraulic oil tank. 
     The control valve  176 R is a spool valve that switches the flow of hydraulic oil so that hydraulic oil discharged by the right main pump  14 R can be supplied to the arm cylinder  8  and that hydraulic oil in the arm cylinder  8  can be discharged to the hydraulic oil tank. 
     The left parallel conduit  42 L is a hydraulic oil line running parallel to the left center bypass conduit  40 L. When the flow of hydraulic oil through the left center bypass conduit  40 L is restricted or blocked by any of the control valves  171 ,  173  and  175 L, the left parallel conduit  42 L can supply hydraulic oil to a control valve further downstream. The right parallel conduit  42 R is a hydraulic oil line running parallel to the right center bypass conduit  40 R. When the flow of hydraulic oil through the right center bypass conduit  40 R is restricted or blocked by any of the control valves  172 ,  174  and  175 R, the right parallel conduit  42 R can supply hydraulic oil to a control valve further downstream. 
     The regulator  13  includes a left regulator  13 L and a right regulator  13 R. The left regulator  13 L controls the discharge quantity of the left main pump  14 L by adjusting the swash plate tilt angle of the left main pump  14 L in accordance with the discharge pressure of the left main pump  14 L. Specifically, the left regulator  13 L, for example, reduces the discharge quantity of the left main pump  14 L by adjusting its swash plate tilt angle, according as the discharge pressure of the left main pump  14 L increases. The same is the case with the right regulator  13 R. This control, which is also referred to as power control (horsepower control), is performed in order to prevent the absorbed power (absorbed horsepower) of the main pump  14 , expressed as the product of discharge pressure and discharge quantity, from exceeding the output power (output horsepower) of the engine  11 . 
     The operating device  26  includes a left operating lever  26 L, a right operating lever  26 R, and travel levers  26 D. The travel levers  26 D include a left travel lever  26 DL and a right travel lever  26 DR. 
     The left operating lever  26 L is used for swing operation and for operating the arm  5 . The left operating lever  26 L is operated forward or backward to introduce a control pressure commensurate with the amount of lever operation to a pilot port of the control valve  176 , which is associated with the arm cylinder  8 , using hydraulic oil discharged by the pilot pump  15 . The left operating lever  26 L is operated rightward or leftward to introduce a control pressure commensurate with the amount of lever operation to a pilot port of the control valve  173 , which is associated with the swing hydraulic motor  2 A, using hydraulic oil discharged by the pilot pump  15 . 
     Specifically, the left operating lever  26 L is operated in an arm closing direction to introduce hydraulic oil to the right pilot port of the control valve  176 L and introduce hydraulic oil to the left pilot port of the control valve  176 R. Furthermore, the left operating lever  26 L is operated in an arm opening direction to introduce hydraulic oil to the left pilot port of the control valve  176 L and introduce hydraulic oil to the right pilot port of the control valve  176 R. Furthermore, the left operating lever  26 L is operated in a counterclockwise swing direction to introduce hydraulic oil to the left pilot port of the control valve  173 , and is operated in a clockwise swing direction to introduce hydraulic oil to the right pilot port of the control valve  173 . 
     The right operating lever  26 R is used to operate the boom  4  and operate the bucket  6 . The right operating lever  26 R is operated forward or backward to introduce a control pressure commensurate with the amount of lever operation to a pilot port of the control valve  175 , which is associated with the boom cylinder  7 , using hydraulic oil discharged by the pilot pump  15 . The right operating lever  26 R is operated rightward or leftward to introduce a control pressure commensurate with the amount of lever operation to a pilot port of the control valve  174 , which is associated with the bucket cylinder  9 , using hydraulic oil discharged by the pilot pump  15 . 
     Specifically, the right operating lever  26 R is operated in a boom lowering direction to introduce hydraulic oil to the right pilot port of the control valve  175 R. Furthermore, the right operating lever  26 R is operated in a boom raising direction to introduce hydraulic oil to the right pilot port of the control valve  175 L and introduce hydraulic oil to the left pilot port of the control valve  175 R. The right operating lever  26 R is operated in a bucket closing direction to introduce hydraulic oil to the left pilot port of the control valve  174 , and is operated in a bucket opening direction to introduce hydraulic oil to the right pilot port of the control valve  174 . 
     The travel levers  26 D are used to operate the crawler  1 C. Specifically, the left travel lever  26 DL is used to operate the left crawler. According to this embodiment, the left travel lever  26 DL is configured to operate together with a left travel pedal. The left travel lever  26 DL is operated forward or backward to introduce a control pressure commensurate with the amount of lever operation to a pilot port of the control valve  171 , using hydraulic oil discharged by the pilot pump  15 . The right travel lever  26 DR is used to operate the right crawler. According to this embodiment, the right travel lever  26 DR is configured to operate together with a right travel pedal. The right travel lever  26 DR is operated forward or backward to introduce a control pressure commensurate with the amount of lever operation to a pilot port of the control valve  172 , using hydraulic oil discharged by the pilot pump  15 . 
     The discharge pressure sensor  28  includes a discharge pressure sensor  28 L and a discharge pressure sensor  28 R. The discharge pressure sensor  28 L detects the discharge pressure of the left main pump  14 L, and outputs the detected value to the controller  30 . The same is the case with the discharge pressure sensor  28 R. 
     The operating pressure sensor  29  includes operating pressure sensors  29 LA,  29 LB,  29 RA,  29 RB,  29 DL and  29 DR. The operating pressure sensor  29 LA detects the details of the operator&#39;s forward or backward operation of the left operating lever  26 L in the form of pressure, and outputs the detected value to the controller  30 . Examples of the details of operation include the direction of lever operation and the amount of lever operation (the angle of lever operation). 
     Likewise, the operating pressure sensor  29 LB detects the details of the operator&#39;s rightward or leftward operation of the left operating lever  26 L in the form of pressure, and outputs the detected value to the controller  30 . The operating pressure sensor  29 RA detects the details of the operator&#39;s forward or backward operation of the right operating lever  26 R in the form of pressure, and outputs the detected value to the controller  30 . The operating pressure sensor  29 RB detects the details of the operator&#39;s rightward or leftward operation of the right operating lever  26 R in the form of pressure, and outputs the detected value to the controller  30 . The operating pressure sensor  29 DL detects the details of the operator&#39;s forward or backward operation of the left travel lever  26 DL in the form of pressure, and outputs the detected value to the controller  30 . The operating pressure sensor  29 DR detects the details of the operator&#39;s forward or backward operation of the right travel lever  26 DR in the form of pressure, and outputs the detected value to the controller  30 . 
     The controller  30  receives the output of the operating pressure sensor  29 , and outputs a control command to the regulator  13  to change the discharge quantity of the main pump  14  on an as-needed basis. 
     Here, negative control on the discharge quantity of the main pump  14  using a throttle  18  and a control pressure sensor  19  is described. The negative control is performed separately from the power control in order to control the discharge quantity of the main pump  14 . The throttle  18  includes a left throttle  18 L and a right throttle  18 R and the control pressure sensor  19  includes a left control pressure sensor  19 L and a right control pressure sensor  19 R. 
     The left throttle  18 L is placed between the most downstream control valve  176 L and the hydraulic oil tank in the left center bypass conduit  40 L. Therefore, the flow of hydraulic oil discharged by the left main pump  14 L is restricted by the left throttle  18 L. The left throttle  18 L generates a control pressure for controlling the left regulator  13 L. The left control pressure sensor  19 L is a sensor for detecting this control pressure, and outputs a detected value to the controller  30 . The controller  30  controls the discharge quantity of the left main pump  14 L by adjusting the swash plate tilt angle of the left main pump  14 L in accordance with this control pressure via the left regulator  13 L. The controller  30  decreases the discharge quantity of the left main pump  14 L as this control pressure increases, and increases the discharge quantity of the left main pump  14 L as this control pressure decreases. The discharge quantity of the right main pump  14 R is controlled in the same manner. 
     Specifically, as illustrated in  FIG. 2 , in a standby state where none of the hydraulic actuators is operated in the shovel  100 , hydraulic oil discharged by the left main pump  14 L arrives at the left throttle  18 L through the left center bypass conduit  40 L. The flow of hydraulic oil discharged by the left main pump  14 L increases the control pressure generated upstream of the left throttle  18 L. As a result, the controller  30  decreases the discharge quantity of the left main pump  14 L to a minimum allowable discharge quantity to reduce pressure loss (pumping loss) during the passage of the discharged hydraulic oil through the left center bypass conduit  40 L. In contrast, when any of the hydraulic actuators is operated, hydraulic oil discharged by the left main pump  14 L flows into the operated hydraulic actuator via a control valve corresponding to the operated hydraulic actuator. The flow of hydraulic oil discharged by the left main pump  14 L that arrives at the left throttle  18 L is reduced in amount or lost, so that the control pressure generated upstream of the left throttle  18 L is reduced. As a result, the controller  30  increases the discharge quantity of the left main pump  14 L to cause sufficient hydraulic oil to flow into the operated hydraulic actuator to ensure driving of the operated hydraulic actuator. The controller  30  controls the discharge quantity of the right main pump  14 R in the same manner. 
     According to the configuration as described above, the hydraulic system of  FIG. 2  can reduce unnecessary energy consumption in the main pump  14  in the standby state. The unnecessary energy consumption includes pumping loss that hydraulic oil discharged by the main pump  14  causes in the center bypass conduit  40 . Furthermore, in the case of actuating a hydraulic actuator, the hydraulic system of  FIG. 2  can ensure that necessary and sufficient hydraulic oil is supplied from the main pump  14  to the hydraulic actuator to be actuated. 
     The control valve  60  is configured to be able to switch the enabled state and the disabled state of the operating device  26 . According to this embodiment, the control valve  60  is a solenoid valve and is configured to operate in response to a current command from the controller  30 . The control valve  60  may be constituted of a combination of a solenoid valve and a hydraulic valve. The enabled state of the operating device  26  is a state where the operator can move an associated driven body by operating the operating device  26 . The disabled state of the operating device  26  is a state where the operator cannot move an associated driven body even when operating the operating device  26 . 
     According to this embodiment, the control valve  60  is a spool solenoid valve that can switch the opening and closing of a pilot line CD 1  connecting the pilot pump  15  and the operating device  26 . Specifically, the control valve  60  is configured to be able to switch the opening and closing of the pilot line CD 1  in response to a command from the controller  30 . More specifically, the control valve  60  is configured to open the pilot line CD 1  when in a first valve position and close the pilot line CD 1  when in a second valve position.  FIG. 2  illustrates that the control valve  60  is in the first position and that the pilot line CD 1  is open. 
     The control valve  60  may also be configured to operate together with a gate lock lever that is not depicted. Specifically, the control valve  60  may also be configured to close the pilot line CD 1  when the gate lock lever is pushed down and open the pilot line CD 1  when the gate lock lever is pulled up. 
     Next, an operator seat unit  20  provided in the cabin  10  is described with reference to  FIG. 3 .  FIG. 3  is a perspective view of the operator seat unit  20  provided in the cabin  10 . 
     The operator seat unit  20  includes an operator seat  24 , console boxes  27 , armrests  31  on a base  22 . 
     The operator seat unit  20  is installed on top of the base  22 , which is fixed to a floor  21  serving as the floor of the cabin  10 , through slide rails and base plates that are hidden in the console boxes  27 . The base plates are configured to be slidable in a forward and a backward direction relative to the base  22  (the floor  21 ) through the slide rails. Accordingly, the operator seat unit  20  is configured to be adjustably positionable in the forward and the backward direction in the cabin  10 . 
     The operator seat  24  includes a seat part  24   a  and a back part  24   b . According to this embodiment, the operator seat  24  is supported on the base  22  through a suspension SP. 
     The console boxes  27  are installed one on each side of the operator seat  24 . The left operating lever  26 L, the right operating lever  26 R, various switches, etc., for operating the shovel  100  are installed on the console boxes  27 . 
     The console boxes  27  include console frames that are hidden inside. The console frames are fixed to the floor  21  through support frames and the base plates hidden in the console boxes  27  and the base  22 . 
     The console frames may be configured to be tiltable relative to the support frames through tilt mechanisms. In this case, when the console frames tilt through tilt operations, the console boxes  27  also tilt, so that the left operating lever  26 L and the right operating lever  26 R also tilt together with the console boxes  27  as a unit. This is because the left operating lever  26 L and the right operating lever  26 R are attached to the console boxes  27 . 
     The armrests  31  are members that the operator&#39;s elbows touch when the operator operates the shovel  100  using the left operating lever  26 L, the right operating lever  26 R, etc. 
     Next, the operating device  26  provided in the cabin  10  is described with reference to  FIG. 4 .  FIG. 4  is a perspective view of the inside of the cabin  10 , illustrating how it looks from the shovel  100  when the operator seated in the operator seat  24  looks forward. 
     According to the example of  FIG. 4 , the operating device  26  includes the left operating lever  26 L, the right operating lever  26 R, the travel levers  26 D, and travel pedals  26 P. The left operating lever  26 L is an operating lever for the operations of opening and closing the arm  5  and swinging the upper swing structure  3 . The right operating lever  26 R is an operating lever for the operations of raising and lowering the boom  4  and opening and closing the bucket  6 . The travel levers  26 D are operating levers for driving the travel hydraulic motors  2 M. The travel pedals  26 P are operating pedals for driving the travel hydraulic motors  2 M. The travel levers  26 D and the travel pedals  26 P are configured to operate in conjunction with each other. 
     A horn button  26 S is a button for honking a horn, and is provided at the top of the left operating lever  26 L. The operator can operate the horn button  26 S with a finger without releasing a hand from the left operating lever  26 L. 
       FIG. 5  is a left side view of the left operating lever  26 L.  FIG. 5  depicts only the right side portion of a boot BT so that the structure of members inside the boot BT can be seen. The left operating lever  26 L and the right operating lever  26 R have mirror image structures. Therefore, the following description of the left operating lever  26 L also applies to the right operating lever  26 R. 
     The left operating lever  26 L mainly includes a signal wire EW, a grip part GR, a lever part LV, a joint part JT, and a holder part HD. 
     The grip part GR is a member that the operator holds with a hand when operating the left operating lever  26 L. The grip part GR is fixed to the top end of the lever part LV. According to this embodiment, the grip part GR is made of synthetic resin. 
     The signal wire EW is a member that electrically connects components such as the horn button  26 S installed on the grip part GR and components such as the controller  30  installed outside the left operating lever  26 L. 
     The lever part LV is a member that is connected to the holder part HD via the joint part JT. According to this embodiment, the lever part LV is a cylindrical member and is made of metal. 
     The joint part JT is a member that connects the lever part LV and the holder part HD. The joint part JT is desirably configured such that a worker can perform tightening with the joint part JT and untightening with a predetermined operation (manual work) without using a tool. That is, the lever part LV is configured to be attachable to and detachable from in a tool-free manner with a predetermined manual operation on the joint part JT. According to the example of  FIG. 5 , the joint part JT is a clamping ring JTa (see  FIGS. 7A and 7B ) and connects the lever part LV and the holder part HD such that the lever part LV and the holder part HD are immovable relative to each other in the direction of an axis AX indicated by a one-dot chain line. 
     The holder part HD is a member to which the lever part LV is detachably attached. According to this embodiment, the holder part HD and the lever part LV are connected via a rotation preventing structure RPM that prevents rotation about the axis AX. 
     The holder part HD is fixed to a remote control valve RV. For example, when the left operating lever  26 L is tilted forward or backward, the holder part HD as well is tilted forward or backward. In this case, the remote control valve RV introduces a control pressure commensurate with the amount of lever operation (for example, the tilt angle of the holder part HD) to a pilot port of the control valve  176 , which is associated with the arm cylinder  8 , using hydraulic oil discharged by the pilot pump  15 . Likewise, when the left operating lever  26 L is tilted leftward or rightward, the remote control valve RV introduces a control pressure commensurate with the amount of lever operation to a pilot port of the control valve  173 , which is associated with the swing hydraulic motor  2 A, using hydraulic oil discharged by the pilot pump  15 . 
     The rotation preventing structure RPM includes, for example, a spigot joint structure, a ball lock structure, or the like.  FIGS. 6A and 6B  illustrates an example configuration of a spigot joint structure SJ. Specifically,  FIG. 6A  is a perspective view of the spigot joint structure SJ, and  FIG. 6B  is a sectional view of the spigot joint structure SJ. 
     According to the example of  FIGS. 6A and 6B , the lever part LV includes a protrusion PT in its end face facing the holder part HD, the protrusion PT protruding toward the holder part HD along the axis AX. The holder part HD includes a recess RS in its end face facing the lever part LV, the recess RS being depressed in such a manner as to mate with the protrusion PT of the lever part LV. 
     According to the example of  FIGS. 6A and 6B , the protrusion PT has a quadrangular prism shape. The protrusion PT, however, may have another shape as long as the protrusion PT can prevent rotation about the axis AX by fitting into the recess RS. Examples of other shapes include other polygonal shapes such as a triangular prism shape and a hexagonal prism shape, an elliptic cylindrical shape, and a gear shape. 
     According to the example of  FIGS. 6A and 6B , a length L 1  of the protrusion PT is equal to a depth D 1  of the recess RS. The length L 1  of the protrusion PT, however, may also be greater than the depth D 1  of the recess RS or smaller than the depth D 1  of the recess RS. The left operating lever  26 L and the right operating lever  26 R may be configured such that their respective lengths can be changed by adjusting the length L 1  of the protrusion PT. 
     The lever part LV and the holder part HD are connected in such a manner as to be unrotatable relative to each other by the rotation preventing structure RPM. Furthermore, the rotation preventing structure RPM limits the angular relationship between the lever part LV and the holder part HD when the lever part LV and the holder part HD are connected. Therefore, the rotation preventing structure RPM can prevent the lever part LV from being connected to the holder part HD with an inappropriate angular relationship. 
     A worker can easily remove the lever part LV from the holder part HD with a predetermined tool-free operation by manually releasing tightening with the joint part JT. Therefore, a worker can easily replace the lever part LV to which the grip part GR is fixed with another lever part LV. 
     The dotted line of  FIG. 4  indicates that another grip part GRa whose angle of attachment is different from that of the grip part GR may be attached in place of the grip part GR. The operator of the shovel  100  may, for example, remove the lever part LV to which the standard grip part GR is fixed, attached in advance to the holder part HD, and instead attach the lever part LV to which her/his own grip part GRa is fixed. The operator of the shovel  100  that can execute a machine control function (an autonomous control function) may attach, to the holder part HD, the lever part LV to which a grip having multiple buttons used in executing the machine control function is fixed, instead of the lever part LV to which the standard grip part GR is fixed. The autonomous control function is a function for causing the shovel  100  to autonomously operate, and includes, for example, a function to cause a hydraulic actuator to autonomously operate independent of the details of the operator&#39;s operation of the operating device  26 . In this case, the left operating lever  26 L may be configured such that multiple signal wires EW (see  FIG. 5 ) corresponding to the multiple buttons are appropriately disposed in the boot BT. 
     Next, an example configuration of the lever part LV, the joint part JT, and the holder part HD is described with reference to  FIGS. 7A and 7B .  FIGS. 7A and 7B  illustrate an example configuration of the lever part LV, the joint part JT, and the holder part HD. Specifically,  FIG. 7A  is a perspective view of the lever part LV, the joint part JT, and the holder part HD, and  FIG. 7B  is a sectional view of the lever part LV, the joint part JT, and the holder part HD. According to the example of  FIGS. 7A and 7B , the lever part LV and the holder part HD are connected via the rotation preventing structure RPM. For clarification, however, the graphical representation of the rotation preventing structure RPM is omitted in  FIGS. 7A and 7B . 
     As illustrated in  FIG. 7B , the lever part LV includes a tapered flange part LVf at its end facing the holder part HD, and the holder part HD includes a tapered flange part HDf at its end facing the lever part LV. The joint part JT is the clamping ring JTa including a thumbscrew TS that serves as an operating part moved by the force of the operator&#39;s fingers. The clamping ring JTa serves as an operated part that is moved or becomes movable by the movement of the operating part. The clamping ring JTa is placed in such a manner as to surround the tapered flange part LVf and the tapered flange part HDf and is tightened with the tapered flange part LVf and the tapered flange part HDf abutting against each other. According to this configuration, the clamping ring JTa serving as the operated part also serves as an engaging part, and the tapered flange part LVf and the tapered flange part HDf operate as engaged parts engaged with each other by the engaging part. The thumbscrew TS is a member for tightening the clamping ring JTa and includes a shaft TSX. 
     This configuration makes it possible for a worker to connect the lever part LV and the holder part HD without requiring a tool such that the lever part LV and the holder part HD are immovable relative to each other in the direction of the axis AX. The lever part LV is connected to the holder part HD via the rotation preventing structure RPM in such a manner as to be relatively unrotatable about the axis AX. 
     Next, another example configuration of the lever part LV, the joint part JT, and the holder part HD is described with reference to  FIGS. 8A through 8C .  FIGS. 8A through 8C  illustrate another example configuration of the lever part LV, the joint part JT, and the holder part HD. Specifically,  FIG. 8A  is a perspective view of the lever part LV, the joint part JT, and the holder part HD, and  FIG. 8B  is a sectional view of the lever part LV, the joint part JT, and the holder part HD.  FIG. 8C  illustrates a cross section perpendicular to the axis AX including a one-dot chain line L 2  of  FIG. 8B . According to the example of  FIGS. 8A through 8C , the lever part LV and the holder part HD are connected via the rotation preventing structure RPM. For clarification, however, the graphical representation of the rotation preventing structure RPM is omitted in  FIGS. 8A through 8C . 
     As illustrated in  FIG. 8B , the lever part LV is configured to have a cylinder at its end facing the holder part HD. The holder part HD is configured to have a cylindrical tube at its end facing the lever part LV. The holder part HD is configured such that a worker can fit the cylinder of the lever part LV into its cylindrical tube. The end of the lever part LV may alternatively be a prism, a square tube, a cylindrical tube, or the like. In this case, the end of the holder part HD may have another shape that can receive the end of the lever part LV. Furthermore, the cylindrical tube of the holder part HD may have a slit extending along the axis AX. Furthermore, while the end of the holder part HD is configured to surround and receive the end of the lever part LV according to the example of  FIGS. 8A through 8C , the end of the lever part LV may be configured to surround and receive the end of the holder part HD. 
     The joint part JT is a clamping ring JTb including a cam lever CL. The clamping ring JTb may be a seat clamp lever used to fix the seatpost of a bicycle. The clamp ring JTb is placed outside the cylindrical tube of the holder HD where the cylindrical tube of the holder part HD and the cylinder of the lever part LV overlap each other, and is tightened by the cam lever CL. According to this configuration, the cam lever CL serves as an operating part, the clamping ring JTb serves as an operated part and an engaging part, the cylindrical tube of the holder part HD serves as an operated part and an engaging part, and the cylinder of the lever part LV serves as an engaged part engaged by the engaging part. 
     This configuration makes it possible for a worker to connect the lever part LV and the holder part HD without requiring a tool such that the lever part LV and the holder part HD are immovable relative to each other in the direction of the axis AX. The lever part LV is connected to the holder part HD via the rotation preventing structure RPM in such a manner as to be relatively unrotatable about the axis AX. 
     Next, yet another example configuration of the lever part LV, the joint part JT, and the holder part HD is described with reference to  FIGS. 9A and 9B .  FIGS. 9A and 9B  illustrate yet another example configuration of the lever part LV, the joint part JT, and the holder part HD. Specifically,  FIG. 9A  is a perspective view of the lever part LV, the joint part JT, and the holder part HD, and  FIG. 9B  is a sectional view of the lever part LV, the joint part JT, and the holder part HD. According to the example of  FIGS. 9A and 9B , the lever part LV and the holder part HD are connected via the rotation preventing structure RPM. For clarification, however, the graphical representation of the rotation preventing structure RPM is omitted in  FIGS. 9A and 9B . 
     As illustrated in  FIG. 9B , the lever part LV is configured to have a cylinder at its end facing the holder part HD. The holder part HD is configured to have a cylindrical tube at its end facing the lever part LV. The holder part HD is configured such that a worker can fit the cylinder of the lever part LV into its cylindrical tube. The end of the lever part LV may alternatively be a prism, a square tube, a cylindrical tube, or the like. In this case, the end of the holder part HD may have another shape that can receive the end of the lever part LV. Furthermore, while the end of the holder part HD is configured to surround and receive the end of the lever part LV according to the example of  FIGS. 9A and 9B , the end of the lever part LV may be configured to surround and receive the end of the holder part HD. 
     The joint part JT is a pin lock mechanism JTc. The pin lock mechanism JTc is constituted mainly of a positioning pin  70 , a button  71 , and a retaining projection  72 . The button  71  is used to retract the retaining projection  72 . A worker can retract the retaining projection  72  into the positioning pin  70  by pushing the button  71  with a finger. 
     The positioning pin  70  is configured to pass through the holder part HD and the lever part LV through a hole H 1  formed in the cylinder of the lever part LV and a hole H 2  formed in the cylindrical tube of the holder part HD. A worker inserts the positioning pin  70  into the hole H 1  and the hole H 2  while pushing the button  71  with a finger, namely, keeping the retaining projection  72  retracted, with the hole H 1  and the hole H 2  being aligned. When the positioning pin  70  passes through the holder part HD and the lever part LV, the worker releases the finger from the button  71  to cause the retaining projection  72  to project from the positioning pin  70 . According to this configuration, the pin lock mechanism JTc servers as an operating part, part of the pin lock mechanism JTc inserted into the space defined by the hole H 1  and the hole H 2  serves as an operated part and an engaging part, and the cylindrical tube of the lever part LV serves as an engaged part engaged by the engaging part. 
     This configuration makes it possible for a worker to connect the lever part LV and the holder part HD without requiring a tool such that the lever part LV and the holder part HD are immovable relative to each other in the direction of the axis AX. The lever part LV is connected to the holder part HD via the rotation preventing structure RPM in such a manner as to be relatively unrotatable about the axis AX. 
     Next, still another example configuration of the lever part LV, the joint part JT, and the holder part HD is described with reference to  FIGS. 10A and 10B .  FIGS. 10A and 10B  illustrate still another example configuration of the lever part LV, the joint part JT, and the holder part HD. Specifically,  FIG. 10A  is a perspective view of the lever part LV, the joint part JT, and the holder part HD, and  FIG. 10B  is a sectional view of the lever part LV, the joint part JT, and the holder part HD. According to the example of  FIGS. 10A and 10B , the lever part LV and the holder part HD are connected via the rotation preventing structure RPM. For clarification, however, the graphical representation of the rotation preventing structure RPM is omitted in  FIGS. 10A and 10B . 
     As illustrated in  FIG. 10B , the holder part HD is configured to have a truncated conical protrusion  73  like a taper shank at its end facing the lever part LV. The lever part LV is configured to have a truncated conical recess  74  corresponding to the truncated conical protrusion  73  of the holder part HD at its end facing the holder part HD. The lever part LV is configured such that a worker can fit the truncated conical protrusion  73  of the holder part HD into the truncated conical recess  74 . The truncated conical protrusion  73  may alternatively be a truncated pyramidal protrusion, a truncated elliptical conical protrusion, or the like. In this case, the truncated conical recess  74  is configured to fit a truncated pyramidal protrusion, a truncated elliptical conical protrusion, or the like. According to this configuration, the lever part LV serves as an operating part, the truncated conical recess  74  serves as an operated part and an engaging part, and the truncated conical protrusion  73  serves as an engaged part engaged by the engaging part. 
     According to the example of  FIGS. 10A and 10B , the joint part JT is a taper fitting structure JTd famed of the truncated conical protrusion  73  and the truncated conical recess  74 . Furthermore, according to the example of  FIGS. 10A and 10B , the holder part HD includes a release mechanism RM. Furthermore, the taper fitting structure JTd, which is configured such that the truncated conical recess  74  of the lever part LV surrounds and receives the truncated conical protrusion  73  of the holder part HD according to the example of  FIGS. 10A and 10B , may also be configured such that the truncated conical recess of the holder part HD surrounds and receives the truncated conical protrusion of the lever part LV. 
     The release mechanism RM is a lever mechanism for removing the lever part LV from the holder part HD, and includes a first lever  75  and a second lever  76 . The second lever  76  is connected to the first lever  75  by a first pin, and the first lever  75  is connected to the holder part HD by a second pin. In removing the lever part LV from the holder part HD, a worker turns the second lever  76  about the first pin until the second lever  76  contacts a stopper  75   a  as indicated by arrow AR 1  in  FIG. 10B . The stopper  75   a  is a projection formed at the end of the first lever  75 , and prevents the second lever  76  from turning a predetermined angle or more about the first pin relative to the first lever  75 . A figure represented by a one-dot chain line in  FIG. 10B  indicates the second lever  76  contacting the stopper  75   a . Thereafter, the worker turns the first lever  75  together with the second lever  76  about the second pin by further turning the second lever  76 . The first lever  75  can turn about the second pin in a direction indicated by arrow AR 2  by contacting an end face of the lever part LV facing the holder part HD and thereafter lifting the end face. A figure represented by a dotted line in  FIG. 10B  indicates the first lever  75  and the second lever  76  when lifting the end face of the lever part LV. Thus, a worker can manually remove the lever part LV from the holder part HD with a predetermined tool-free operation. 
     This configuration makes it possible for a worker to connect the lever part LV and the holder part HD without requiring a tool such that the lever part LV and the holder part HD are immovable relative to each other in the direction of the axis AX. The lever part LV is connected to the holder part HD via the rotation preventing structure RPM in such a manner as to be relatively unrotatable about the axis AX. 
     Next, yet still another example configuration of the lever part LV, the joint part JT, and the holder part HD is described with reference to  FIGS. 11A through 11C .  FIGS. 11A through 11C  illustrate yet still another example configuration of the lever part LV, the joint part JT, and the holder part HD. Specifically,  FIG. 11A  is a perspective view of the lever part LV, the joint part JT, and the holder part HD, and  FIG. 11B  is a sectional view of the lever part LV, the joint part JT, and the holder part HD.  FIG. 11C  illustrates a cross section perpendicular to the axis AX including a one-dot chain line L 3  of  FIG. 11B . According to the example of  FIGS. 11A through 11C , the lever part LV and the holder part HD are connected via the rotation preventing structure RPM. For clarification, however, the graphical representation of the rotation preventing structure RPM is omitted in  FIGS. 11A through 11C . 
     As illustrated in  FIG. 11B , the lever part LV is configured to have a cylinder at its end facing the holder part HD. The holder part HD is configured to have a cylindrical tube at its end facing the lever part LV. The holder part HD is configured such that a worker can fit the cylinder of the lever part LV into its cylindrical tube. The end of the lever part LV may alternatively be a prism, a square tube, a cylindrical tube, or the like. In this case, the end of the holder part HD may have another shape that can receive the end of the lever part LV. 
     The joint part JT is a clamping lever JTe with an eccentric cam. The clamping lever die with an eccentric cam is constituted mainly of an eccentric cam EC, a pin PN 1 , a pin PN 2 , and the cam lever CL. According to this configuration, the cam lever CL serves as an operating part, and the eccentric cam EC serves as an operated part and an engaging part. The lever part LV serves as an engaged part engaged by the engaging part. The eccentric cam EC is a member placed in such a manner as to be rotatable about the pin PN 1 , and is configured to fit in a recess LVa formed in the lever part LV. The cam lever CL is a member that presses the eccentric cam EC against the holder part HD, and is configured to be rotatable about the pin PN 2  supported by the pin PN 1 . Each of  FIGS. 11A through 11C  illustrates that the eccentric cam EC fitting in the recess LVa is pressed down by the cam lever CL. A worker can release the eccentric cam EC from being pressed against the holder part HD by the cam lever CL by rotating the cam lever CL about the pin PN 2  with the force of a finger as indicated by arrow AR 3  in  FIG. 11A . The eccentric cam EC released from the pressing can rotate about the pin PN 1 . A worker can disengage the eccentric cam EC from the recess LVa of the lever part LV by rotating the eccentric cam EC about the pin PN 1  with the force of a finger as indicated by arrow AR 4  in  FIG. 11C . A figure represented by a dotted line in  FIG. 11C  indicates the eccentric cam EC rotated 180° about the pin PN 1  to be at a release position. The release position means a position at which the fitting of the recess LVa of the lever part LV and the eccentric cam EC can be terminated. The lever part LV released from the fitting can move in the direction of the axis AX relative to the holder part HD. Thus, a worker can manually remove the lever part LV from the holder part HD with a predetermined tool-free operation. 
     This configuration makes it possible for a worker to connect the lever part LV and the holder part. HD without requiring a tool such that the lever part LV and the holder part HD are immovable relative to each other in the direction of the axis AX. The lever part LV is connected to the holder part HD via the rotation preventing structure RPM in such a manner as to be relatively unrotatable about the axis AX. 
     Next, even another example configuration of the lever part LV, the joint part JT, and the holder part HD is described with reference to  FIGS. 12A through 12C .  FIGS. 12A through 12C  illustrate even another example configuration of the lever part LV, the joint part JT, and the holder part HD. Specifically,  FIG. 12A  is a perspective view of the lever part LV, the joint part JT, and the holder part HD, and  FIG. 12B  is a sectional view of the lever part LV, the joint part JT, and the holder part HD.  FIG. 12C  is a perspective view of a rotary wedge RW that is a component of the joint part JT and a recess LVb of the lever part LV in which the rotary wedge RW fits. According to the example of  FIGS. 12A through 12C , the lever part LV and the holder part HD are connected via the rotation preventing structure RPM. For clarification, however, the graphical representation of the rotation preventing structure RPM is omitted in  FIGS. 12A through 12C . 
     The joint part JT of  FIGS. 12A through 12C  are a clamping lever JTf with a rotary wedge. The clamping lever JTf with a rotary wedge is constituted mainly of the rotary wedge RW, the pin PN 1 , the pin PN 2 , and the cam lever CL. According to this configuration, the cam lever CL serves as an operating part, and the rotary wedge RW serves as an operated part and an engaging part. The lever part LV serves as an engaged part engaged by the engaging part. 
     The configuration of  FIGS. 12A through 12C  is different in using the clamping lever JTf with a rotary wedge from, but otherwise equal to, the configuration of  FIGS. 11A through 11C  which uses the clamping lever JTe with an eccentric cam including the eccentric cam EC. Therefore, a description of a common portion is omitted, and differences are described in detail. 
     The rotary wedge RW is a member placed in such a manner as to be rotatable about the pin PN 1 , and is configured to fit in the recess LVb formed in the lever part LV. The cam lever CL is a member that presses the rotary wedge RW against the holder part HD, and is configured to be rotatable about the pin PN 2  supported by the pin PN 1 . Each of  FIGS. 12A and 12B  illustrates that the rotary wedge RW fitting in the recess LVb is pressed down by the cam lever CL. A worker can release the rotary wedge RW from being pressed against the holder part HD by the cam lever CL by rotating the cam lever CL about the pin PN 2  with the force of a finger as indicated by arrow AR 5  in  FIG. 12A . The rotary wedge RW released from the pressing can rotate about the pin PN 1 . A worker can disengage the rotary wedge RW from the recess LVb of the lever part LV by rotating the rotary wedge RW about the pin PN 1  with the force of a finger as indicated by arrow AR 6  in  FIG. 12C . The lever part LV released from the fitting can move in the direction of the axis AX relative to the holder part HD. Thus, a worker can manually remove the lever part LV from the holder part HD with a predetermined tool-free operation. 
     This configuration makes it possible for a worker to connect the lever part LV and the holder part HD without requiring a tool such that the lever part LV and the holder part HD are immovable relative to each other in the direction of the axis AX. The lever part LV is connected to the holder part HD via the rotation preventing structure RPM in such a manner as to be relatively unrotatable about the axis AX. 
     Next, yet even another example configuration of the lever part LV, the joint part JT, and the holder part HD is described with reference to  FIGS. 13A and 13B .  FIGS. 13A and 13B  illustrate yet even another example configuration of the lever part LV, the joint part JT, and the holder part HD. Specifically,  FIG. 13A  is a perspective view of the lever part LV, the joint part JT, and the holder part HD, and  FIG. 13B  illustrates a cross section perpendicular to the axis AX including a one-dot chain line L 4  of  FIG. 13A . According to the example of  FIGS. 13A and 13B , the lever part LV and the holder part HD are connected via the rotation preventing structure RPM. For clarification, however, the graphical representation of the rotation preventing structure RPM is omitted in  FIGS. 13A and 13B . 
     As illustrated in  FIG. 13A , the lever part LV is configured to have a cylinder at its end facing the holder part HD. The holder part HD is configured to have a cylindrical tube at its end facing the lever part LV. The holder part HD is configured such that a worker can fit the cylinder of the lever part LV into its cylindrical tube. The end of the lever part LV may alternatively be a prism, a square tube, a cylindrical tube, or the like. In this case, the end of the holder part HD may have another shape that can receive the end of the lever part LV. Furthermore, while the end of the holder part HD is configured to surround and receive the end of the lever part LV according to the example of  FIGS. 13A and 13B  the end of the lever part LV may be configured to surround and receive the end of the holder part HD. 
     The joint part JT is a clamping lever JTg with a sliding wedge. The clamping lever JTg with a sliding wedge is constituted mainly of a screw member SR, a sliding wedge SW, the pin PN 2 , and the cam lever CL. According to this configuration, the cam lever CL serves as an operating part, and the sliding wedge SW serves as an operated part and an engaging part. The lever part LV serves as an engaged part engaged by the engaging part. 
     The screw member SR is an example of a fastener member that is inserted into a through hole HDa formed in the cylinder of the holder part HD. According to the example of  FIGS. 13A and 13B , the screw member SR is an externally threaded screw corresponding to an internal thread formed in the through hole HDa. 
     As illustrated in  FIG. 13B , the through hole HDa extends through the cylindrical tube of the holder part HD in a direction perpendicular to the axis AX to form an opening HDb that exposes a surface of the lever part LV. 
     The sliding wedge SW is a member that is placed in the through hole HDa to be pressed against the lever part LV through the opening HDb. According to the example of  FIGS. 13A and 13B , the sliding wedge SW is a collar member having a through hole through which the screw member SR passes. The sliding wedge SW is configured to have a curved surface that fits the external circumferential surface of the lever part LV in a part corresponding to the opening HDb. 
     A worker inserts the screw member SR to which the sliding wedge SW is attached into the through hole HDa with the cylinder of the lever part LV being inserted into the cylindrical tube of the holder part HD. The worker causes the sliding wedge SW to contact a surface of the lever part LV using the screw member SR and thereafter presses the sliding wedge SW against the surface of the lever part LV using the cam lever CL. Thus, a worker can manually connect the lever part LV to the holder part HD with a predetermined tool-free operation. 
     This configuration makes it possible for a worker to connect the lever part LV and the holder part HD without requiring a tool such that the lever part LV and the holder part HD are immovable relative to each other in the direction of the axis AX. The lever part LV is connected to the holder part HD via the rotation preventing structure RPM in such a manner as to be relatively unrotatable about the axis AX. 
     Next, still even another example configuration of the lever part LV, the joint part JT, and the holder part HD is described with reference to  FIGS. 14A and 14B .  FIGS. 14A and 14B  illustrate still even another example configuration of the lever part LV, the joint part JT, and the holder part HD. Specifically,  FIGS. 14A and 14B  are perspective views of the lever part LV, the joint part JT, and the holder part HD.  FIG. 14A  illustrates the lever part LV and the holder part HD before being connected by the joint part JT, and  FIG. 14B  illustrates the lever part LV and the holder part HD after being connected by the joint part JT. According to the example of  FIGS. 14A and 14B , the joint part JT serves as the rotation preventing structure RPM. Therefore, the spigot joint structure SJ is not employed. 
     As illustrated in  FIG. 14A , the holder part HD is configured to have a cylinder  77  at its end facing the lever part LV. The lever part LV is configured to have a cylindrical tube  78  at its end facing the holder part HD. The lever part LV is configured such that a worker can fit the cylinder  77  of the holder part HD into the cylindrical tube  78 . The cylinder  77  may alternatively be a prism, an elliptic cylinder, or the like. In this case, the cylindrical tube  78  is configured to fit a prism, an elliptic cylinder, or the like. 
     According to the example of  FIGS. 14A and 14B , the joint part JT is a ball lock mechanism JTh. The ball lock mechanism JTh is constituted mainly of the cylinder  77 , the cylindrical tube  78 , balls BL, and a sleeve SL. 
     The sleeve SL is a member slidably attached to the end of the lever part LV facing the holder part HD, and can have a first state where the sleeve SL is moved in the +Z direction as illustrated in  FIG. 14A  and a second state where the sleeve SL is moved in the −Z direction (not depicted). The sleeve SL is typically urged in the −Z direction by an urging member such as a spring, and is in the second state when a worker is not in contact with the sleeve SL. That is, when a worker releases a hand from the sleeve SL in the first state, the sleeve SL returns to the second state. 
     The balls BL are configured to protrude outward from the external circumferential surface of the cylindrical tube  78  when the sleeve SL is in the first state and to protrude inward from the internal circumferential surface of the cylindrical tube  78  when the sleeve SL is in the second state. According to the example of  FIGS. 14A and 14B , the balls BL are arranged at regular intervals along a circumferential direction of the cylindrical tube  78 . The balls BL may also be arranged at irregular intervals along a circumferential direction of the cylindrical tube  78 . This is for preventing the lever part LV from being connected to the holder part HD with an inappropriate angular relationship. 
     The balls BL are configured to engage with recesses  77   a  formed in the exterior circumferential surface of the cylinder  77  when the sleeve SL is in the second state, namely, when the balls BL are protruding inward from the internal circumferential surface of the cylindrical tube  78 . When the balls BL are engaged with the recesses  77   a , the lever part LV and the holder part HD are immovable relative to each other in the direction of the axis AX and are unrotatable relative to each other about the axis AX. According to this configuration, the lever part LV serves as an operating part and the balls BL serve as an operated part and an engaging part. The recesses  77   a  serve as an engaged part engaged by the engaging part. 
     A worker can engage the balls BL with the recesses  77   a  by pushing up the sleeve SL with the force of fingers into the first state of  FIG. 14A , fitting the cylinder  77  into the cylindrical tube  78 , and thereafter releasing a hand from the sleeve SL to return the sleeve SL to the second state. That is, a worker can manually connect the lever part LV to the holder part HD with a predetermined tool-free operation. 
     The sleeve SL may also be configured such that when the cylindrical tube  78  is pressed against the cylinder  77 , the sleeve SL automatically and temporarily enters the first state using the pressing force and that when the balls BL thereafter engage with the recesses  77   a , the sleeve SL automatically returns to the second state using a spring force. 
     Furthermore, a worker brings about a state where the balls BL can protrude from the exterior circumferential surface of the cylindrical tube  78  by pushing up the sleeve SL with the force of fingers in a direction indicated by arrow AR 7  in  FIG. 14B . In this state, by lifting the lever part LV, the worker can manually separate the lever part LV from the holder part HD with a predetermined tool-free operation. 
     This configuration makes it possible for a worker to connect the lever part LV and the holder part HD without requiring a tool such that the lever part LV and the holder part HD are immovable relative to each other in the direction of the axis AX and are unrotatable relative to each other about the axis AX. 
     As described above, the shovel  100  according to an embodiment of the present invention includes the upper swing structure  3 , the cabin  10  mounted on the upper swing structure  3 , and an operating lever provided in the cabin  10 . The operating lever includes a left operating lever  26 L and a right operating lever  26 R. The operating lever includes a lever part LV to which a grip part GR is fixed, the holder part HD to which the lever part LV is connected, and the joint part JT connecting the lever part LV and the holder part HD. The lever part LV is configured to be attachable to and detachable from the holder part HD in a tool-free manner with a predetermined manual operation on the joint part JT. That is, the lever part LV is configured to be manually replaceable with ease. 
     According to this configuration, the shovel  100  allows more flexible adjustment of the position of the operating lever because multiple lever parts LV to which various grip parts GR that differ in shape, width, length, or the like are fixed can be attached and detached. As a result, the operator can select and use the lever part LV that fits her/his own body shape (shoulder width, arm length, hand size, or the like). The operator can also select and use the lever part LV that provides a preferable grip position. The operator can also change the lever part LV according to the work details of the shovel  100 . The operator can also easily replace the lever part LV that is damaged, contaminated or degraded with another lever part LV. Therefore, the shovel  100  can meet the operator&#39;s high requirements with respect to the operating lever. 
     Furthermore, because the lever part LV is configured to be replaceable, the operating lever does not have to have an adjustment mechanism for adjusting the angle of fixation of the lever part LV about the axis AX. Therefore, it is possible to prevent the occurrence of problems due to the looseness, backlash, failure, or the like of the adjustment mechanism. 
     The lever part LV is desirably connected to the holder part HD via the joint part JT. According to this configuration, the lever part LV and the holder part HD are connected to be immovable relative to each other in the direction of the axis AX. Therefore, the backlash, looseness, undesirable extension and contraction, etc., of the lever part LV are prevented with more reliability. 
     The joint part JT may be, for example, the clamping ring JTa including the thumbscrew TS as illustrated in  FIGS. 7A and 7B . The lever part LV may include the tapered flange part LVf serving as a first flange part, and the holder part HD may include the tapered flange part HDf serving as a second flange part. In this case, the tapered flange part LVf and the tapered flange part HDf are clamped together by the clamping ring JTa, so that the lever part LV is connected to the holder part HD. This configuration makes it possible for a worker to easily remove the lever part LV from the holder part HD without using a tool. Furthermore, a worker can easily attach a lever part LV different from the removed lever part LV to the holder part HD without using a tool. 
     The lever part LV may also be connected to the holder part HD by, for example, the clamping ring JTb including the cam lever CL (see  FIGS. 8A through 8C ), the pin lock mechanism JTc (see  FIGS. 9A and 9B ), the taper fitting structure JTd (see  FIGS. 10A and 10B ), the clamp lever JTe with an eccentric cam (see  FIGS. 11A through 11C ), the clamp lever JTf with a rotary wedge (see  FIGS. 12A through 12C ), or the clamp lever JTg with a sliding wedge (see  FIGS. 13A and 13B ). This configuration makes it possible for a worker to connect the lever part LV and the holder part HD without requiring a tool such that the lever part LV and the holder part HD are immovable relative to each other in the direction of the axis AX. 
     The operating lever desirably includes a rotation preventing structure. In this case, the rotation preventing structure is, for example, the spigot joint structure SJ. The rotation preventing structure can ensure that the lever part LV is prevented from rotating relative to the holder part HD. 
     The lever part LV may also be connected to the holder part HD by the ball lock mechanism JTh (see  FIGS. 14A and 14B ). This configuration makes it possible for a worker to connect the lever part LV and the holder part HD without requiring a tool such that the lever part LV and the holder part HD are immovable relative to each other in the direction of the axis AX and are unrotatable relative to each other about the axis AX. 
     An embodiment of the present invention is described in detail above. The present invention, however, is not limited to the above-described embodiment. Various variations, substitutions, etc., may be applied to the above-described embodiment without departing from the scope of the present invention. Furthermore, the separately described features may be combined to the extent that no technical contradiction is caused. 
     For example, according to the above-described embodiment, a hydraulic operation system including a hydraulic pilot circuit is disclosed. Specifically, in a hydraulic pilot circuit associated with the left operating lever  26 L, hydraulic oil supplied from the pilot pump  15  to the remote control valve RV of the left operating lever  26 L is conveyed to a pilot port of the control valve  176  serving as an arm control valve at a flow rate commensurate with the degree of opening of the remote control valve RV opened or closed by the tilt of the left operating lever  26 L. 
     Instead of a hydraulic operation system including such a hydraulic pilot circuit, however, an electric operation system with an electric pilot circuit including an electric operating lever may be adopted. In this case, the amount of lever operation of the electric operating lever is input to the controller  30  as an electrical signal. Furthermore, a solenoid valve is placed between the pilot pump  15  and a pilot port of each control valve. The solenoid valve is configured to operate in response to an electrical signal from the controller  30 . According to this configuration, when a manual operation using the electric operating lever is performed, the controller  30  can move each control valve in the control valve unit  17  by increasing or decreasing a pilot pressure by controlling the solenoid valve with an electrical signal commensurate with the amount of lever operation. Each control valve may be constituted of a solenoid spool valve. In this case, the solenoid spool valve operates in response to an electrical signal from the controller  30  commensurate with the amount of lever operation of the electric operating lever. 
     When an electric operation system including an electric operating lever is adopted, the controller  30  can more easily execute an autonomous control function than in the case where a hydraulic operation system including a hydraulic operating lever is adopted. 
       FIG. 15  illustrates an example configuration of an electric operation system. Specifically, the electric operation system of  FIG. 15  is an example of a boom operation system, and is constituted mainly of the pilot pressure-operated control valve unit  17 , the right operating lever  26 R serving as an electric operating lever, the controller  30 , a solenoid valve  65  for boom raising operation, and a solenoid valve  66  for boom lowering operation. The electric operation system of  FIG. 15  may also be likewise applied to an arm operation system, a bucket operation system, a swing operation system, a travel operation system, etc. 
     As illustrated in  FIG. 2 , the pilot pressure-operated control valve unit  17  includes the control valve  171  associated with the left travel hydraulic motor  2 ML, the control valve  172  associated with the right travel hydraulic motor  2 MR, the control valve  173  associated with the swing hydraulic motor  2 A, the control valve  174  associated with the bucket cylinder  9 , the control valve  175  associated with the boom cylinder  7 , the control valve  176  associated with the arm cylinder  8 , etc. The solenoid valve  65  is configured to be able to adjust the flow area of a conduit connecting the pilot pump  15  and the raising-side pilot port of the control valve  175 . The solenoid valve  66  is configured to be able to adjust the flow area of a conduit connecting the pilot pump  15  and the lowering-side pilot port of the control valve  175 . 
     When a manual operation is performed, the controller  30  generates a boom raising operation signal (electrical signal) or a boom lowering operation signal (electrical signal) in accordance with an operation signal (electrical signal) output by an operation signal generating part  26 Ra of the right operating lever  26 R. The operation signal output by the operation signal generating part  26 Ra of the right operating lever  26 R is an electrical signal that changes in accordance with the amount of operation and the direction of operation of the right operating lever  26 R. 
     Specifically, when the right operating lever  26 R is operated in the boom raising direction, the controller  30  outputs a boom raising operation signal (electrical signal) commensurate with the amount of lever operation to the solenoid valve  65 . The solenoid valve  65  adjusts the flow area in accordance with the boom raising operation signal (electrical signal) to control a pilot pressure serving as a boom raising operation signal (pressure signal) that acts on the raising-side pilot port of the control valve  175 . Likewise, when the right operating lever  26 R is operated in the boom lowering direction, the controller  30  outputs a boom lowering operation signal (electrical signal) commensurate with the amount of lever operation to the solenoid valve  66 . The solenoid valve  66  adjusts the flow area in accordance with the boom lowering operation signal (electrical signal) to control a pilot pressure serving as a boom lowering operation signal (pressure signal) that acts on the lowering-side pilot port of the control valve  175 . 
     In the case of executing the autonomous control function, the controller  30 , for example, generates the boom raising operation signal (electrical signal) or the lowering operation signal (electrical signal) in accordance with an autonomous control signal (electrical signal) instead of responding to the operation signal (electrical signal) output by the operation signal generating part  26 Ra of the right operating lever  26 R. The autonomous control signal may be an electrical signal generated by the controller  30  or an electrical signal generated by an external control device other than the controller  30 .