JP2018188908A - Leg opening type hydraulic shovel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a V-shaped leg opening type hydraulic shovel capable of inhibiting one traveling device from opening excessively.SOLUTION: A leg opening type hydraulic shovel comprises: a traveling body 10; a revolving superstructure provided on the upper part of the traveling body 10 in a revolvable manner; and a work machine attached to the revolving superstructure. The traveling body 10 comprises: a center frame 14 for supporting the revolving superstructure; left and right traveling devices 12 rotatably coupled to the center frame 14, the traveling devices being capable of opening their legs in a V-shaped form; left and right links 15 for connecting the center frame 14 to the left and right traveling devices 12, respectively; and a cylinder 67 for opening/closing the legs of the left and right traveling devices 12. The leg opening type hydraulic shovel comprises: left and right stoppers 70 disposed between an upper face plate and lower face plate 51 of the center frame 14, left and right stoppers having slots 72 through which rotation shafts 62 for the left and right links 15 pass; and left and right support shafts 71 provided on the center frame 14, the left and right support shafts rotatably supporting the left and right stoppers 70 in a horizontal direction.SELECTED DRAWING: Figure 3

Description

  The present invention widens the distance between the front portions of the crawler-type left and right traveling devices and opens the left and right traveling devices in a V shape so that an area between the front portions of the left and right traveling devices can be excavated. The present invention relates to a leg-type hydraulic excavator. For example, it relates to an open leg type hydraulic excavator that performs excavation work while changing the position in small steps by a traveling body at the bottom of a vertical hole (deep foundation pile hole) into which the deep foundation pile is inserted by the deep foundation method.

  For example, in the deep foundation method where deep foundation piles (foundations) of new towers are constructed deep underground when rebuilding steel towers such as transmission lines in mountainous areas, a small-diameter vertical hole for drilling deep foundation piles is drilled. To do. However, in the drilling work of vertical holes in mountainous areas, it is often impossible to secure a carry-in route and a wide scaffold and use large-scale mechanical equipment. In such a case, for example, a disassembled excavator that can be transported by a helicopter, an ultra-small hydraulic excavator, or the like may be used. This is a construction method in which a disassembled excavator is assembled on site and a vertical hole is excavated from the ground surface to a certain depth, and an ultra-small hydraulic excavator is inserted into the vertical hole with a crane or the like to dig the vertical hole.

  However, inside a vertical hole with a small diameter (for example, about 2.5 m in diameter), even if it is an ultra-small hydraulic excavator, the area that can actually be excavated by its own traveling body that touches the bottom of the vertical hole is obstructive, and is small. In addition, the position and orientation of the traveling body must be changed, and the work cannot be efficiently performed. Therefore, as described in Patent Document 1, a hydraulic pressure capable of excavating a region between the left and right traveling devices by opening the front side of the crawler-type left and right traveling devices and opening them in a V shape. There is an excavator. Hereinafter, this type of hydraulic excavator is referred to as an “open leg type hydraulic excavator”.

Japanese Utility Model Publication No.59-102654

  The open leg type hydraulic excavator described in Patent Document 1 connects the left and right traveling devices to the center frame of the track frame via links, respectively, and the left and right traveling by one hydraulic cylinder connecting the left and right links. It is the structure which opens an apparatus. For example, when an outrigger is provided at the rear of the center frame to suppress the rear tilt of the aircraft, if the hydraulic cylinder is extended with the outrigger grounded and the center frame fixed to the ground, Can cause variations. For example, if the right traveling device is caught by the ground and restrained, only the left traveling device having a low operating resistance opens as the cylinder extends. In this way, if the left and right traveling devices have a difference in the leg angle, one traveling device will be excessively opened, and if the outrigger is provided at the rear as described above, one traveling device may interfere with the outrigger. There is sex.

  An object of the present invention is to suppress an excessive opening of one traveling device in an open leg type hydraulic excavator that expands the distance between the front portions of the crawler-type left and right traveling devices and opens the legs in a V shape. It is.

  In order to achieve the above object, the present invention provides a traveling body, a revolving body provided on the upper portion of the traveling body so as to be able to swivel, a working machine attached to the revolving body, a hydraulic actuator for driving the working machine, and the hydraulic actuator A hydraulic pump that discharges the pressure oil that drives the hydraulic pump, and a prime mover that drives the hydraulic pump, and the traveling body is rotatably connected to the center frame that supports the revolving body and the center frame. The left and right traveling devices that can be opened in a V-shape by expanding the front portion of the left and right links, the left and right links that respectively connect the center frame and the left and right traveling devices, and the left and right links In an open leg type hydraulic excavator provided with a cylinder for opening and closing a traveling device, the left and right links or front links are disposed between an upper surface plate and a lower surface plate of the center frame. Left and right stoppers having elongated holes through which connecting pins are provided in the cylinder, and left and right support shafts that are provided on both left and right side portions of the center frame and support the left and right stoppers so as to be rotatable in the horizontal direction. In addition, the maximum leg angle of the left and right traveling devices is individually limited by restraining the connecting pin with the elongated hole of the stopper.

  According to the present invention, in the open leg type hydraulic excavator that expands the distance between the front portions of the crawler-type left and right traveling devices and opens the legs in a V shape, it is possible to prevent one traveling device from being excessively opened. Can do. Thereby, even if an outrigger or the like is provided at the rear portion, it is possible to suppress the traveling device from interfering with this.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing the overall configuration of an open leg type hydraulic excavator according to an embodiment of the present invention, and shows an open leg type excavator equipped with a bucket as an attachment. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing the overall configuration of an open leg type excavator according to an embodiment of the present invention, and shows an open leg type excavator equipped with a breaker as an attachment. It is a top view of the traveling body of the open leg type hydraulic excavator shown in FIG. It is the figure which looked at the left part of the center frame of the traveling body shown in FIG. 3 from the front. It is a top view showing the mode of the open leg type hydraulic excavator shown in FIG. 1 which works by closing a leg at the bottom of a vertical hole. It is a top view showing the mode of the open leg type hydraulic excavator shown in FIG. 1 which works by opening the leg at the bottom of the vertical hole. FIG. 4 is a plan view of the traveling body shown in FIG. 3 in a state in which the operating resistance of the leg is different between the left and right traveling devices and only the right traveling device is opened. FIG. 2 is a plan view of the open leg type hydraulic excavator shown in FIG. 1 in a state in which the operating resistance of the leg is different between the left and right traveling devices and only the right traveling device is opened.

  Embodiments of the present invention will be described below with reference to the drawings.

1. FIG. 1 and FIG. 2 are side views showing the overall configuration of an open leg hydraulic excavator according to an embodiment of the present invention. 1 shows an open leg type excavator with a bucket as an attachment, and FIG. 2 shows an open leg excavator with a breaker as an attachment. In the following description, when “hydraulic excavator” is described without particular notice, it means an open leg type excavator. Further, the front (left in the figure) of the driver's seat of the excavator 100 in FIG.

  The excavator 100 is inserted into a vertical hole (deep foundation pile hole) H into which a deep foundation pile (not shown) is inserted by a deep foundation method, for example, and excavation work is performed while changing the position in small increments by a traveling body at the bottom of the vertical hole. It is a work machine that digs vertical holes. The excavator 100 includes a traveling body 10, a revolving body 30, and a work machine (front work machine) 40.

2. The traveling body The traveling body 10 is a crawler type (crawler type) traveling body for the hydraulic excavator 100 to travel on its own, and includes a track frame 11, left and right traveling devices 12, and an outrigger 13. The track frame 11 is a frame of the traveling body 10 and includes a center frame 14 (FIG. 3), left and right links 15 (FIG. 3), and left and right side frames 16 so as to be H-shaped in plan view when the legs are closed. Is formed. The outrigger 13 is provided at the rear portion (right side portion in FIG. 1) of the center frame 14. The outrigger is not provided at the front portion of the center frame 14 and the outrigger 13 is provided only at the rear portion because it may interfere with excavation work. The outrigger 13 swings up and down by a cylinder (not shown), and the height of the outrigger 13 is adjusted according to the scene, so that the backward tilt of the excavator 100 during work can be suppressed. Details of the configuration of the track frame 11 will be described later.

  The left and right traveling devices 12 include a driven wheel 21, a driving wheel 22, a crawler (crawler) 23, and a traveling motor 24. The driven wheel 21 is rotatably supported at each front end (left end in FIG. 1) of the left and right side frames 16 of the track frame 11, and the driving wheel 22 is rotatably supported at each rear end (right end in FIG. 1) of the left and right side frames 16, respectively. ing. The left and right side frames 16 of the track frame 11 also serve as the frames of the left and right traveling devices 12, respectively. The crawler belts 23 are hung around the driven wheels 21 and the drive wheels 22 in the left and right traveling devices 12, respectively. In the left and right traveling devices 12, the output shaft of the traveling motor 24 is connected to the rotation shaft of the drive wheel 22. When the traveling motor 24 is driven, the crawler belt 23 wound around the driven wheel 21 and the driving wheel 22 is circulated and the traveling operation of the excavator 100 is performed. The travel motor 24 is a hydraulic motor. In the case of the hydraulic excavator 100 of the present embodiment, the length in the longitudinal direction of the traveling device 12 (at least the length of the side frame 16) is shorter than that of a general hydraulic excavator for convenience of moving around the bottom of the small-diameter vertical hole H. It is about the same as or shorter than the length of the swivel body 30 in the front-rear direction. In particular, in the present embodiment, when the left and right traveling devices 12 are in parallel (when the legs are closed as shown in FIG. 5), the outer sides of the left and right traveling devices 12 in the vehicle width direction are substantially square opposite sides in plan view. Thus, the distance and length of the traveling device 12 are adjusted. Thereby, stability is ensured although it is the short traveling apparatus 12. FIG.

3. Revolving body The revolving body 30 includes a revolving frame (not shown), a driver's seat 32, a counterweight 33, a machine room 34, and the like. The turning frame is a base frame of the turning body 30 and is provided on the upper portion of the track frame 11 (center frame 14) via the turning wheel 25. A turning motor (not shown) is mounted in the vicinity of the turning wheel 25 on the turning frame, and the turning body 30 is connected to the traveling body 10 by engaging the output shaft of the turning motor with a gear provided on the turning wheel 25. Turn around the vertical axis. Although an electric motor can be used as the swing motor, a hydraulic motor is used in this embodiment.

  The driver's seat 32 is disposed at a position that is offset to one side (left side in the present embodiment) in the left-right direction with respect to the turning center of the turning body 30. The upper side of the driver seat 32 is covered with a canopy 35. An operating device 36 is arranged at the front of the turning frame so as to be positioned in front of the driver's seat 32. The operation device 36 is a plurality of operation devices such as a lever device and pedals for instructing operations of the work implement 40, the traveling body 10, and the revolving body 30. The counter weight 33 is a weight for balancing the weight with the work machine 40 and is provided at the rear end of the turning frame. The counterweight 33 in the present embodiment is formed integrally with a cover (outer wall) of the machine room 34 (also serves as a cover) and covers each device accommodated in the machine room 34. Further, the excavator 100 is ultra-compact, and the column 35a disposed at the rear of the swing body 30 among the columns supporting the canopy 35 rises from the upper portion of the counterweight 33 or a cover (not shown) thereon, and the swing body 30. Located near the rear edge.

  Although not shown, in the machine chamber 34, in addition to the electric motor 37, a hydraulic pump, a cooling fan, a valve unit, a hydraulic oil tank, a fuel tank, a controller 38, and the like are accommodated. The electric motor 37 is a prime mover that drives a hydraulic pump, and is driven by, for example, electric power supplied from a generator separately from the excavator 100 via a cable (not shown). However, the power supply (generator, battery, etc.) may be mounted in the machine room 34 instead of the power supply from the external power supply. The hydraulic pump driven by the electric motor 37 sucks the hydraulic oil in the hydraulic oil tank and discharges it as pressure oil. The pressure oil discharged from the hydraulic pump is controlled by a valve unit that operates in accordance with the operation of the operation device 36 and is supplied to a corresponding hydraulic actuator. The controller 38 is a control device that controls electrical components. The hydraulic excavator 100 according to the present embodiment is very small as shown in FIG. 1, and the layout of the accommodation equipment in the machine room 34 is arranged such that the controller 38 and the electric motor 37 are arranged vertically below the driver's seat 32. The turning body 30 is configured to have a very small diameter by devising three-dimensionally. In the present embodiment, a controller 38 is disposed above the electric motor 37. Although not shown in particular, the driver's seat 32 has a structure in which the rear portion pivots up and down with the front portion as a fulcrum. When the rear portion of the driver's seat 32 is lifted and tilted, the upper side of the controller 38 is opened. 38 can be accessed.

4). The work machine 40 is an articulated front work machine including a work arm 41 and a work tool 44 as an attachment, and is attached to the revolving body 30. The work arm 41 includes a boom 42, an arm 43, a boom cylinder (not shown), an arm cylinder 46, and a work tool cylinder 47. The boom 42 is rotatably connected to the front portion of the revolving body 30, the arm 43 is rotatably connected to the tip of the boom 42, and the work tool 44 is rotatably connected to the tip of the arm 43. The boom 42, the arm 43, and the work tool 44 all rotate about a rotation shaft that extends horizontally from side to side. Although FIG. 1 illustrates an example in which a bucket is mounted as the work tool 44 and FIG. 2 illustrates an example in which a breaker is mounted as the work tool 44, other attachments can also be mounted. Further, both ends of the boom cylinder are connected to the revolving body 30 and the boom 42, and the arm cylinder 46 is connected to the boom 42 and the arm 43, respectively. The work tool cylinder 47 has a base end connected to the arm 43 and a tip connected to the tip of the arm 43 and the work tool 44 via a link 48. The boom cylinder, the arm cylinder 46 and the work tool cylinder 47 are all hydraulic actuators, are driven by pressure oil discharged from a hydraulic pump, and drive the work machine 40 by an expansion / contraction operation.

5. Track Frame FIG. 3 is a plan view of the traveling body of the excavator shown in FIGS. 1 and 2, and FIG. 4 is a view of the left portion of the center frame as viewed from the front. FIG. 3 shows a state in which the distance between the front portions of the left and right traveling devices 12 is widened (the distance between the rear portions is narrowed) and the left and right traveling devices 12 are opened in a V shape. For clarity of the structure, the upper surface plate 52 (FIG. 4) to which the turning wheel 25 is attached in the center frame is not shown. As described above, the track frame 11 includes the center frame 14, the link 15, and the side frames 16 (FIGS. 1 and 2).

  The center frame 14 is a main frame of the track frame 11. The link 15 and the side frame 16 are connected to the left and right sides, and a revolving body 30 is supported on the upper part. The center frame 14 includes a lower plate 51, an upper plate 52 (FIG. 4), a front plate 53, a rear plate 54, a left side plate 55, and a right side plate 56. The front plate 53, the rear plate 54, the left side plate 55, and the right side plate 56 are plate-like members that stand vertically. The center frame 14 is configured such that a square frame with the front plate 53, the rear plate 54, the left side plate 55, and the right side plate 56 as front, rear, left and right surfaces is sandwiched from above and below by the horizontal lower surface plate 51 and upper surface plate 52, respectively. . The bottom plate 51, the top plate 52, the front plate 53, the rear plate 54, the left side plate 55, and the right side plate 56 are fixed to each other by welding or the like.

  The left and right links 15 are disposed at a height between the lower surface plate 51 and the upper surface plate 52 of the center frame 14 and include a first arm 58 and a second arm 59, respectively. The first arm 58 is connected to the lower surface plate 51 and the upper surface plate 52 of the center frame 14 through a rotating shaft 61 extending vertically, and is horizontal with respect to the center frame 14 around the rotating shaft 61. It can be rotated along. The rotation shafts 61 of the left and right links 15 are respectively located on the left and right of the front portion of the center frame 14. The base end of the second arm 59 is connected to the distal end of the first arm 58 via a rotating shaft 62 extending vertically, and the second arm 59 extends along the horizontal plane with respect to the first arm 58 around the rotating shaft 62. It can be rotated. The distal end portion of the second arm 59 is connected to a bracket 64 that protrudes inward in the vehicle width direction from the front portion of the side frame 16 (FIG. 1 and the like) of the track frame 11 via a rotating shaft 63 that extends vertically. . Therefore, the second arm 59 can also rotate along the horizontal plane with respect to the side frame 16 with the rotation shaft 63 as a fulcrum. Further, brackets 65 projecting inward in the vehicle width direction are provided at the rear portions of the left and right side frames 16, respectively. The bracket 65 is disposed at a height between the lower surface plate 51 and the upper surface plate 52 of the center frame 14, and is connected to the lower surface plate 51 and the upper surface plate 52 via a rotating shaft 66 extending vertically. The center frame 14 can be rotated along a horizontal plane with respect to the center frame 14. These rotation shafts 66 are located on the left and right of the rear portion of the center frame 14, respectively. Reinforcing plates 68 are provided on the left and right sides of the center frame 14 at a position in front of the rotation shaft 61 and a position in front of the rotation shaft 66, respectively. These four reinforcing plates 68 are vertically raised members extending in the left-right direction, and connect the lower surface plate 51 and the upper surface plate 52.

  As described above, the bracket 65 of the side frame 16 is directly connected to the center frame 14 at the rear part of the left and right traveling apparatuses 12, while the bracket 64 of the side frame 16 is centered via the link 15 at the front part of the left and right traveling apparatuses 12. It is connected to the frame 14. As a result, the left and right traveling devices 12 can be horizontally rotated around the rotation shaft 66 to expand the distance between the front parts of each other and open the legs in a V shape so as to reduce the distance between the rear parts. It can be done.

  Further, the rotating shafts 62 of the left and right links 15 are connected by a single cylinder 67. The cylinder 67 extends left and right and is disposed through openings provided in the left side plate 55 and the right side plate 56 of the center frame 14. The dimensions in the left-right direction of the lower surface plate 51 and the upper surface plate 52 are set so as to cover all or most of the cylinder 67 extended to the maximum. As the cylinder 67 expands and contracts, the left and right traveling devices 12 are opened or closed in a V shape as shown in FIG. 3 (the left and right traveling devices 12 extend in the front-rear direction and are parallel to each other). become). FIG. 5 is a plan view showing the state of the hydraulic excavator 100 that works by closing the legs at the bottom of the vertical hole H, and FIG. 6 is a plan view showing the state of the hydraulic excavator 100 that works by opening the legs at the bottom of the vertical hole H. Indicated.

6). Stopper A stopper 70 is disposed between the lower surface plate 51 and the upper surface plate 52 of the center frame 14. The left and right stoppers 70 are rod-like and horizontal flat plate-like members, and have long holes 72 through which the connecting pins pass. The long hole 72 extends in the longitudinal direction of the stopper 70 and opens vertically. In the present embodiment, the rotating shaft 62 that connects the left and right links 50 and the cylinder 67 is used for the connecting pin that passes through the long hole 72. These stoppers 70 are connected to the center frame 14 so as to be rotatable in the horizontal direction by left and right support shafts 71 provided separately from the rotation shaft 66. The left and right support shafts 71 extend in the vertical direction, and are supported by a bracket 69 (FIG. 3) provided on the upper plate 52 of the center frame 14 at the upper portion and on a reinforcing plate 68 described later. However, the bracket 69 can be omitted when the support shaft 71 is extended to penetrate the upper surface plate 52 and the lower surface plate 51 of the center frame 14 and the upper and lower surfaces of the support shaft 71 are supported by the upper surface plate 52 and the lower surface plate 51. The left and right support shafts 71 are positioned on the front side of the rotation shaft 66 in the left and right sides of the rear portion of the center frame 14, and are separated from the rotation shaft 66 by the reinforcing plate 68.

  With such a configuration, in this embodiment, the maximum opening angle of the left and right traveling devices 12 is individually restricted by restraining the rotating shaft 62 by the elongated hole 72 of the stopper 70. In this embodiment, the individual maximum leg angle of the left and right traveling devices 12 is about 45 degrees with respect to the center line extending in the front-rear direction of the center frame 14, and the relative maximum leg angle of the left and right traveling devices 12 is about It is 90 degrees. As a result, as shown in FIG. 3, the traveling device 12 does not interfere with the outrigger 13 even when the left and right traveling devices 12 are opened to the maximum. In addition, the grounding portion of the outrigger 13 is also formed in a right triangle shape along the rear edges of the left and right traveling devices 12 when the legs are fully opened.

7). Operation When excavating the vertical hole H as a deep pile pile of a steel tower in a mountainous area, for example, excavating the vertical hole H from the ground surface to a certain depth with a disassembled hydraulic excavator assembled locally, and then excavating the hydraulic excavator 100 with a crane or the like Into the vertical hole H. When operating the excavator 100, the operator sits in the driver's seat 32 and operates the operating device 36 as appropriate. Accordingly, the excavator 100 can be moved by the traveling body 10, the excavation work can be performed by the work machine 40, and the revolving body 30 can be swung. For example, the excavation work is performed by excavating the bottom of the vertical hole H using a bucket as the work tool 44 as shown in FIG. 1, or using the breaker as the work tool 44 as shown in FIG. Or crushing the bedrock of the bottom. The excavated earth and sand, gravel, etc. are crushed with a bucket and loaded into a separately prepared container, and the container is lifted with a crane or the like and carried out of the vertical hole H.

  For example, when it is necessary to open the leg and excavate the region between the left and right traveling devices 12, the operator operates the driver seat 32 appropriately to extend the cylinder 67. At that time, if the movement resistance of the left and right traveling devices 12 is not biased, both traveling devices 12 rotate as the cylinder 67 extends, and as shown in FIG. 3 and FIG. Open the leg. However, when the left and right traveling devices 12 are biased in the operating resistance of the open legs, the traveling device 12 having the smaller operating resistance is opened in advance. The operation in that case will be described next.

  FIG. 7 is a plan view of the traveling body 10 in a state in which the operating resistance of the open legs is different between the left and right traveling devices and only the right traveling device is opened, and FIG. 8 is a plan view of the excavator 100 in that state. 7 is a diagram corresponding to FIG. 3, and FIG. 8 is a diagram corresponding to FIG. 5 and FIG. In the example of FIGS. 7 and 8, for example, it is assumed that the left traveling device 12 is caught on the ground and the operating resistance of the leg opening operation is larger than that of the right traveling device 12. In the state where the left and right traveling devices 12 are closed as shown in FIG. 5, the rotating shaft 62 is located on the innermost side in the vehicle width direction within its own movement range. In the example of FIG. 7, as shown with respect to the left traveling device 12, the rotating shaft 62 is positioned at a position aligned with the rotating shafts 61 and 66 when the legs are closed. When the cylinder 67 is extended from this state, the rotating shaft 62 of the right traveling device 12 with low open leg movement resistance moves outward in the vehicle width direction, and the stopper 70 engages with the rotating shaft 62 through the elongated hole 72. It turns outward in the vehicle width direction. When the rotating shaft 62 reaches the end of the elongated hole 72 of the stopper 70 (the end opposite to the support shaft 71), the rotating shaft 62 is restrained by the stopper 70. Thus, in a state where the right traveling device 12 is fully opened, the right traveling device 12 is further opened even if the left traveling device 12 is not fully opened and the cylinder 67 still has an extension. There is no. Thereafter, if the cylinder 67 is further extended, the right traveling device 12 is restrained, and the left traveling device 12 whose operating resistance magnitude has been reversed and decreased is finally opened, and finally shown in FIG. Thus, the left and right traveling devices 12 are opened to the maximum angle.

8). Advantages (1) According to this embodiment, since the traveling device 12 can be first opened in a V shape, the legs are opened to excavate between the left and right traveling devices 12 or the left and right crawler belts 23 are rotated in reverse. By doing so, it is possible to move horizontally in an arc shape at the bottom of the vertical hole H. Therefore, even in a narrow vertical hole H, a small turn is possible, and even when an appropriate distance cannot be taken from the excavation point, excavation can be performed to the lower part of the front portion of the swivel body 30, so that the work can be efficiently performed.

  At this time, in the ultra-small hydraulic excavator 100, the traveling body 10 is also small, and the left and right traveling devices 12 are individually connected to the center frame 14 by cylinders (that is, a dedicated cylinder is provided for each of the left and right traveling devices 12). There is no room on the layout that can be configured. Since the right and left traveling devices 12 are opened by one cylinder 67, for example, the right traveling device is caught by the ground and restrained as described above. Only the lower left hand drive will open. As described above, when a difference occurs in the leg angle between the left and right traveling devices 12, one traveling device 12 may be excessively opened, and one traveling device 12 may interfere with the outrigger 13 provided at the rear.

  Therefore, in the present embodiment, a stopper 70 is provided for individually limiting the leg opening angle of the left and right traveling devices 12. As a result, the distance between the front portions of the crawler-type left and right traveling devices 12 is increased to suppress the excessive opening of one traveling device 12 in the open leg type hydraulic excavator 100 that opens in a V shape. be able to. Thereby, it can suppress that the traveling apparatus 12 interferes with the outrigger 13 etc. which were provided in the rear part.

  (2) In order to ensure the structural strength of the center frame 14, a member such as the reinforcing plate 68 is necessary as appropriate. If the stopper 70 is connected to the center frame 14 by the rotation shaft 66, if the stopper 70 is arranged between the lower surface plate 51 and the upper surface plate 52 of the center frame 14, the stopper engaged with the rotation shafts 62 and 66. 70 interferes with the reinforcing plate 68. Therefore, when the rotation shaft 66 extends from the upper surface plate 52 of the center frame 14 and the stopper 70 is disposed above the upper surface plate 52, interference between the stopper 70 and the reinforcing plate 68 can be avoided. It will interfere with the face plate 52. If the stopper 70 is arranged on the upper side of the center frame 14, the upper surface plate 52 must be cut out to allow the rotation of the rotating shaft 62, and the structural strength of the center frame 14 is reduced. The same applies to the case where the rotation shaft 66 extends downward from the lower surface plate 51 of the center frame 14 and the stopper 70 is disposed below the lower surface plate 51. In particular, when a stopper is disposed on the lower side of the center frame 14, if the area of the lower surface plate 51 is reduced by cutting out, the lower surface plate 51 protects the cylinder 67 and the like from gravel that jumps up from the ground during work. It is structurally disadvantageous.

  Therefore, in the present embodiment, the support shaft 71 is provided separately from the rotation shaft 66 and the stopper 70 is supported by the dedicated support shaft 71, so that interference with the reinforcing plate 68 can be avoided and the lower surface plate of the center frame 14 can be avoided. A stopper 70 can be disposed between the upper plate 51 and the upper plate 52. Accordingly, it is not necessary to cut out the lower surface plate 51 and the upper surface plate 52, and the deterioration of the strength of the center frame 14 and the protective function of the cylinder 67 can be suppressed.

  (3) Since the rotating shaft 62 that connects the first arm 58 and the second arm 59 of the left and right links 15 also serves as a connecting pin that passes through the elongated hole 72 of the stopper 70, the configuration can be simplified and the number of parts can be reduced. It is done.

  (4) In this embodiment, the left and right traveling devices 12 are not directly connected by the cylinder 67, but the left and right links 15 are connected by the cylinder 67. Thereby, the expansion / contraction operation of the cylinder 67 can be efficiently converted into the rotational motion of the traveling device 12, and the length and stroke of the cylinder 67 can be suppressed.

9. In the above embodiment, in order to obtain the above effect (2), the stopper 70 is connected to the center frame 14 by a dedicated support shaft 71 in addition to the rotation shaft 60 that is the rotation fulcrum of the traveling device 12. However, it is not necessarily limited to this configuration as long as the essential effect (1) is obtained. For example, when the structural strength of the center frame 14 can be sufficiently secured without the reinforcing plate 68, the stopper 70 may be connected to the center frame 14 by the rotating shaft 66. In addition, in order to obtain the effect (3), the configuration in which the connecting pin that passes through the elongated hole 72 of the stopper 70 is also used as the rotating shaft 62 of the link 15 is illustrated, but the connecting pin may be moved as the cylinder 67 expands and contracts. Therefore, a dedicated connecting pin provided separately from the rotating shaft 62 in another part of the left and right links 15 (for example, the first arm 58 and the second arm 59) or another part of the cylinder 67 (for example, the end of the tube or rod). May be configured to pass through the elongated hole 72.

  Further, a plurality of cylinders 67 may be provided as long as it can be installed. In this case, the left and right traveling devices 12 can be individually rotated by separate cylinders, but a cylinder unit in which a plurality of cylinders are connected to increase the stroke amount may be replaced with the cylinder 67. .

  Further, the case where the invention is applied to the hydraulic excavator 100 equipped with the electric motor 37 as a prime mover for driving the hydraulic pump has been described as an example. However, when the excavator 100 can be operated remotely, or when exhaust gas is not a problem at the operation site, an engine (internal combustion engine) may be used as a prime mover instead of the electric motor 37.

DESCRIPTION OF SYMBOLS 10 ... Running body, 12 ... Traveling apparatus, 14 ... Center frame, 15 ... Link, 30 ... Revolving body, 37 ... Electric motor (prime mover), 40 ... Working machine, 46 ... Arm cylinder (hydraulic actuator), 47 ... Work tool cylinder (Hydraulic actuator), 51 ... bottom plate, 52 ... top plate, 62 ... rotating shaft (connecting pin), 67 ... cylinder, 70 ... stopper, 71 ... support shaft, 72 ... long hole, 100 ... open leg type hydraulic excavator

Claims (3)

A traveling body, a swiveling body provided on the top of the traveling body so as to be able to swivel, a working machine attached to the swiveling body, a hydraulic actuator that drives the working machine, a hydraulic pump that discharges pressure oil that drives the hydraulic actuator, and A prime mover for driving the hydraulic pump, wherein the traveling body is pivotally connected to the center frame for supporting the revolving body and the center frame so as to increase a distance between the front portions of each of the traveling bodies. The left and right traveling devices that can be opened to the left, the left and right links that connect the center frame and the left and right traveling devices respectively, and the cylinder that connects the left and right links to open and close the left and right traveling devices. In the open leg type hydraulic excavator,
Left and right stoppers having elongated holes that are disposed between the upper and lower plates of the center frame and that pass through connecting pins provided on the left and right links or the cylinder;
Provided with left and right support shafts which are provided on both left and right side portions of the center frame and support the left and right stoppers so as to be horizontally rotatable;
The open leg type hydraulic excavator is characterized in that the maximum leg angle of the left and right traveling devices is individually restricted by restraining the connecting pin with a long hole of the stopper.   2. The open leg type hydraulic excavator according to claim 1, wherein the left and right support shafts are different shafts from a rotation shaft that rotatably supports the left and right traveling devices with respect to the center frame. Leg type hydraulic excavator.   2. The open leg type excavator according to claim 1, wherein the left and right connecting pins are rotating shafts connecting the left and right links and the cylinder.

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