JP2023102194A - Work device - Google Patents

Abstract

To provide a work device allowing changeover operation at a pivotal connection position of a first link member of a link mechanism and a hydraulic cylinder to be easily carried out.SOLUTION: A tilt bucket 70 is pivotally connected to a tip part of an arm 34 so as to freely swing vertically as well as vertically swung through a link mechanism 80 by a bucket cylinder 39. A first link member 81 of the link mechanism 80 comprises a plurality of pivotal connection parts capable of being pivotally connected to the tip part of the bucket cylinder 39. The pivotal connection parts are placed so as to be aligned on the same circular arc a center of which is a pivotal connection axis line of an arm 34 of a base end of the bucket cylinder 39 in a state the first link member 81 is positioned in a reference posture for the arm 34.SELECTED DRAWING: Figure 24

Description

The present invention relates to a work device having an arm to which a working attachment can be attached.

2. Description of the Related Art Conventionally, work vehicles such as shovel loaders and hydraulic excavators (also called excavators, backhoes, etc.) used for excavating the ground or moving excavated earth and sand are widely known. Such a working vehicle is equipped with a working device having an arm that can swing up and down on a vehicle body configured to be able to travel, and attachments for various tasks such as a bucket, a chip breaker (also simply referred to as a "breaker"), and an auger device are detachably attached to the tip of the arm. By detaching and exchanging the attachment according to the purpose of the work, the prescribed work can be performed efficiently.

Among such work devices, there is known one in which an attachment (for example, a bucket) attached to the tip of an arm so as to be able to swing vertically is vertically swung by a hydraulic cylinder via a link mechanism (see, for example, Patent Document 1 below). A known link mechanism has a first link member whose one end is pivotally connected to an arm so as to be able to swing vertically, and a second link member whose one end is connected to an attachment and whose other end is pivotally connected to the first link member so as to be able to swing vertically. A hydraulic cylinder is known to have a base end pivotally connected to an arm so as to be able to swing up and down, and a tip end pivotally connected to a link mechanism on a pivot shaft of two link members.

2. Description of the Related Art In a work device, it is sometimes desirable to switch the operation performance of an attachment operated by a hydraulic cylinder, for example, the swing range and digging force of a bucket when the attachment is a bucket, depending on the work situation and work content. Conventionally, there has been known a work device in which a first link member is provided with a plurality of pivot portions that can be pivotally connected to a tip portion of a hydraulic cylinder, and the operating performance of the bucket is switched by selectively switching the pivot connection position between the hydraulic cylinder and the first link member among the plurality of pivot portions (see, for example, Patent Document 2 below).

Japanese Patent Application Laid-Open No. 2007-314981 JP 2005-188157 A

In the working device as described above, the operation of switching the pivotally connected position between the hydraulic cylinder and the first link member is generally performed as follows. First, the pivotal connection between the distal end portion of the hydraulic cylinder and the first link member at a certain pivotal connection position (the pivotal connection position before switching) is released. Next, in order to pivotally connect the tip of the hydraulic cylinder and the first link member at another pivoting position (pivoting position after switching), the tip of the hydraulic cylinder is aligned with the pivoting position after switching. This alignment is performed by extending and contracting the hydraulic cylinder to adjust its length and swinging the hydraulic cylinder about the pivot axis between the base end and the arm. After the alignment is completed, the distal end portion of the hydraulic cylinder and the first link member are pivotally connected.

When switching the pivotal connection position between the hydraulic cylinder and the first link member in the working device as described above, it is necessary to align the distal end of the hydraulic cylinder with the post-switching pivotal connection position. However, in the conventional working device, the alignment is performed while the length of the hydraulic cylinder is adjusted by expanding and contracting the hydraulic cylinder with the pivotal connection between the tip of the hydraulic cylinder and the first link member released. Therefore, there is a problem that it takes time and effort to switch the pivoting position.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a working device that can easily switch the pivotally connected position between the first link member of the link mechanism and the hydraulic cylinder.

In order to achieve the above object, the present invention provides an arm that can swing vertically, a work attachment (for example, the tilt bucket 70 in the embodiment) that can be mounted on the arm so that it can swing vertically, a first link member that has one end that is pivotally connected to the arm so that it can swing vertically, and a second link member that has one end connected to the attachment and the other end to which the first link member can swing vertically when the attachment is attached to the arm so that it can swing vertically, a base end portion of which is pivotally connected to the arm and a tip end portion of which is pivotally connected to the first link member so as to be vertically swingable; and an attachment hydraulic cylinder (e.g., bucket cylinder 39 in the embodiment) that expands and contracts to vertically swing the attachment with respect to the arm. A working device (e.g., a shovel device 30 in the embodiment) capable of selectively switching and pivotally connecting a hydraulic cylinder and a hydraulic cylinder between the plurality of pivoting portions. Further, in the working device according to the present invention, in a state in which the attachment is attached to the arm so as to be vertically swingable, one end of the second link member is pivotally connected to the attachment and the other end to the first link member so as to be vertically swingable, and the base end of the attachment hydraulic cylinder is pivotally connected to one of the plurality of pivotally connected portions of the first link member so as to be vertically swingable, the first link member is operated by the attachment hydraulic cylinder. can be vertically swung to position the first link member in a predetermined reference posture with respect to the arm, and in a state in which the first link member is positioned in the reference posture with respect to the arm, the plurality of pivotally connected portions are arranged so as to line up on the same circular arc centered on the pivot line between the base end portion of the attachment hydraulic cylinder and the arm.

In the above-described working device, it is preferable that the first link member is provided with a posture confirmation positioning portion for visually confirming whether or not the first link member is positioned in the reference posture with respect to the arm.

The above-described working device further includes a stopper member for aligning the pivotal position of the attachment hydraulic cylinder relative to the first link member when the first link member is positioned in the reference posture with respect to the arm, the pivotal connection between the tip portion of the attachment hydraulic cylinder and one pivotal connection portion is released to swing the attachment hydraulic cylinder about the pivot axis, and when the tip portion of the attachment hydraulic cylinder opposes another pivotal connection portion in a pivotable state, the stopper member is provided for regulating pivotal movement of the attachment hydraulic cylinder with respect to the first link member. is preferred.

In the working device described above, it is preferable that the stopper member can be attached to and detached from the first link member.

As described above, in the working device according to the present invention, in a state in which the first link member is positioned with respect to the arm in the reference posture, the plurality of pivotally connected portions of the first link member are arranged so as to line up on the same circular arc centering on the axis of the pivotal connection with the arm at the base end of the hydraulic cylinder for attachment. Therefore, in a state in which the first link member is positioned in the reference posture with respect to the arm, by releasing the pivotal connection between the tip portion of the attachment hydraulic cylinder and one of the pivotally connected portions and swinging the attachment hydraulic cylinder about the axis of the pivotal connection with the arm, it is possible to align the tip portion of the attachment hydraulic cylinder with the other pivotally connected portion without adjusting the length of the attachment hydraulic cylinder. Therefore, according to the working device of the present invention, it is possible to easily switch the pivotally connected position between the attachment hydraulic cylinder and the first link member.

In the working device according to the present invention, the first link member is provided with the posture confirmation alignment portion for visually confirming whether or not the first link member is positioned in the reference posture with respect to the arm, so that the first link member can be easily positioned in the reference posture with respect to the arm.

In the working device according to the present invention, in a state in which the first link member is positioned in the reference posture with respect to the arm, the pivotal connection between the distal end portion of the attachment hydraulic cylinder and one pivotal connection portion is released to swing the attachment hydraulic cylinder about the pivotal axis with the arm, and when the distal end portion of the attachment hydraulic cylinder opposes another pivotal connection portion in a pivotable state, the stopper member for aligning the pivotal connection position is provided for restricting the pivotal movement of the attachment hydraulic cylinder with respect to the first link member, It is possible to easily align the distal end portion of the attachment hydraulic cylinder and another pivotal connection portion.

In the working device according to the present invention, the stopper member can be attached to and detached from the first link member, so that the stopper member can be attached to the first link member only when switching the pivotally connected position between the attachment hydraulic cylinder and the first link member, and can be removed from the first link member when the switching operation is not performed. Therefore, by removing the stopper member from the first link member during work, it is possible to prevent the swinging range of the attachment hydraulic cylinder from being restricted by the stopper member.

1 is a perspective view of a hydraulic excavator equipped with an excavator device; FIG. It is the side view which looked at the said hydraulic excavator from the vehicle left side. It is a top view of the said hydraulic excavator. It is a rear view of the said hydraulic excavator. FIG. 2 is a block diagram showing the configuration of a hydraulic control system for the excavator; FIG. 4 is a perspective view of a link mechanism that connects the arm and bucket cylinder of the excavator and the tilt bucket pivotally connected to the arm. It is another perspective view of the said link mechanism. 3 is an exploded perspective view showing the configuration of the link mechanism; FIG. It is a perspective view of the left 1st link member of the said link mechanism. It is the side view which looked at the said left 1st link member from the said arm side. It is the front view which looked at the said left 1st link member from the vehicle front side. It is the side view which looked at the said left 1st link member from the vehicle left side. It is a perspective view of the right 1st link member of the said link mechanism. It is the side view which looked at the said right 1st link member from the vehicle right side. It is the front view which looked at the said right 1st link member from the vehicle front side. It is the side view which looked at the said right 1st link member from the said arm side. It is a perspective view of the 2nd link member of the said link mechanism. It is a perspective view of the bucket cylinder of the said shovel apparatus. FIG. 4 is a diagram showing a swing range of the tilt bucket when the link mechanism is in the first pivoted state; FIG. 10 is a diagram showing the swinging range of the tilt bucket when the link mechanism is in the second pivoted state; FIG. 4 is a diagram illustrating a state of the hydraulic excavator before performing a pivoting position switching operation of the link mechanism from the first pivoting state to the second pivoting state; FIG. 10 is a diagram illustrating the first procedure in the upper pivot position switching operation; It is a figure which illustrates the next procedure in the said pivot connection position switching operation|work. It is a figure which illustrates the next further procedure in the said pivot connection position switching operation|work. It is a figure which illustrates the next further procedure in the said pivot connection position switching operation|work. It is a figure which illustrates the next further procedure in the said pivot connection position switching operation|work. It is a figure which illustrates the next further procedure in the said pivot connection position switching operation|work. It is a figure which illustrates the next further procedure in the said pivot connection position switching operation|work. FIG. 5 is a diagram illustrating a state of the link mechanism when the pivot position switching operation is completed; FIG. 4 is a diagram illustrating a state of the excavator when the pivotal position switching operation is completed; FIG. 4 is a diagram illustrating a state of the hydraulic excavator after completion of the pivot position switching work;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, an excavator device 30 mounted on a wheel-type hydraulic excavator (excavator) will be described as an example of a working device according to the present invention. First, the overall configuration of the hydraulic excavator 1 will be described with reference to FIGS. 1 to 4. FIG.

As shown in FIGS. 1 to 4, the hydraulic excavator 1 includes a traveling body 10 configured to travel, a revolving body 20 provided above the traveling body 10 so as to be capable of horizontal rotation, and a shovel device 30 provided in front of the revolving body 20.

The traveling body 10 includes left and right double-tire front wheels 12, 12 serving as steering wheels and left and right double-tire rear wheels 13, 13 serving as drive wheels on both left and right sides of a traveling body frame 11, respectively. Underneath the traveling body frame 11, a traveling motor (not shown) that rotationally drives the rear wheels 13, 13 via a power transmission mechanism such as a drive shaft 14, and a steering cylinder (not shown) that steers the front wheels 12, 12 are provided. The traveling body 10 can travel in any direction and at any speed by controlling the rotational operation of the travel motor and the telescopic operation of the steering cylinder. A blade 16 is provided on the front portion of the traveling body frame 11 so as to be vertically swingable. The blade 16 is configured to be vertically swingable by extending and contracting a blade cylinder 17 that is straddled between the blade 16 and the traveling body frame 11 . Left and right outriggers 18, 18 are provided on the rear portion of the traveling body frame 11 so as to be vertically swingable. The outriggers 18 , 18 are configured to be vertically swingable by extending and contracting left and right outrigger cylinders 19 , 19 straddled between the traveling body frame 11 .

A turning mechanism 3 is provided at the center of the upper portion of the traveling body frame 11 . Although not shown, the turning mechanism 3 has an inner ring fixed to the traveling body frame 11, an outer ring fixed to the turning body 20, a turning motor provided on the turning body 20, and a rotary center joint for enabling hydraulic oil supply between the turning body 20 and the traveling body 10. The revolving body 20 is horizontally rotatable on the traveling body frame 11 via the revolving mechanism 3, and is configured to be able to revolve in the horizontal direction with respect to the traveling body 10 by operating the revolving motor to rotate forward or reverse.

The revolving body 20 has a revolving body frame 21 provided on the traveling body frame 11 so as to be horizontally rotatable via the revolving mechanism 3 , and an operator cabin 25 provided on the revolving body frame 21 . A front portion of the revolving body frame 21 is provided with a revolving body side bracket 22 projecting forward. Further, the revolving body 20 is provided with mounting chambers (not shown) for mounting an engine (shown as "engine 61" in FIG. 5) and the like, which will be described later, on the rear and right sides of the operator's cabin 25. A curved counterweight 27 and a loading chamber cover 28 that can be vertically opened and closed are provided on the rear wall portion forming the loading chamber.

The excavator device 30 includes an excavator-side bracket 31 which is provided on the revolving body-side bracket 22 so as to be able to swing in the horizontal direction about a vertical axis; a first boom 32 which is pivotally connected to the upper end of the excavator-side bracket 31 via a first pivot pin P1 so as to be vertically swingable (raising and lowering motion); An arm 34 is pivotally connected to the distal end of 33 via a third pivot pin P3 so as to be vertically swingable (flexible and stretchable). A tilting bucket 70, which is an example of a work attachment, is attached to the tip of the arm 34 via a fourth pivot pin P4 so as to be vertically swingable.

Further, the excavator device 30 includes a swing cylinder 35 straddled between the swing body frame 21 and the excavator-side bracket 31, a first boom cylinder 36 straddled between the excavator-side bracket 31 and the first boom 32, a pair of left and right second boom cylinders 37, 37 straddled between the first boom 32 and the second boom 33, an arm cylinder 38 straddled between the second boom 33 and the arm 34, and a base end (cylinder-side end) of the boom cylinder. It has a bucket cylinder 39 pivotally connected to the arm 34 via a 5 pivot pin P5 so as to be able to swing vertically, and a link mechanism 80 (details will be described later) provided to connect the tilt bucket 70 with the tip of the arm 34 and the bucket cylinder 39 in a state where the tilt bucket 70 is attached to the tip of the arm 34 so as to be able to swing vertically.

The excavator-side bracket 31 is configured to swing laterally with respect to the revolving body-side bracket 22 (revolving body frame 21 ) by extending and contracting the swing cylinder 35 . The first boom 32 is configured to be vertically swingable with respect to the excavator-side bracket 31 by extending and contracting the first boom cylinder 36 . The second boom 33 is configured to be vertically swingable with respect to the first boom 32 by extending and retracting left and right second boom cylinders 37 , 37 . The arm 34 is configured to be vertically swingable with respect to the second boom 33 by extending and retracting the arm cylinder 38 . The tilt bucket 70 is configured to be vertically swingable with respect to the arm 34 via a link mechanism 80 by extending and retracting the bucket cylinder 39 .

The tilt bucket 70 has a bucket body 71, a bucket bracket 72 that holds the bucket body 71 so that it can swing in the left-right direction, and a tilting hydraulic actuator 73 that is provided between the bucket body 71 and the bucket bracket 72 and swings the bucket body 71 in the left-right direction with respect to the bucket bracket 72. Instead of the tilt bucket 70, various attachments such as a normal bucket, a breaker, a crusher, a cutter, and an auger can be attached to the tip of the arm 34 and the link mechanism 80 so as to be vertically swingable. A plurality of connection ports (not shown) to which hydraulic hoses for supplying hydraulic oil to the hydraulic actuators (including the tilting hydraulic actuator 73) constituting the attachments can be connected when these attachments are mounted are provided at the tip of the upper surface of the arm 34.

The operator cabin 25 is formed in a substantially rectangular box shape to form an operation room in which an operator can board. Although not shown, the operator's cabin 25 includes an operator seat in which the operator can sit facing forward, a traveling operation device for performing traveling operation of the traveling vehicle 10 (rotating operation of the rear wheels 13, 13), a steering device for steering operation of the traveling vehicle 10 (steering of the front wheels 12, 12), and a work operating device for operating the blade 16, operating the outriggers 18, 18, turning the revolving body 20, and operating the shovel device 30 (see FIG. 5). (illustrated as "work operation device 41"), a display device for displaying various vehicle information in the hydraulic excavator 1, and various operation switches.

The travel operation device includes travel operation members (e.g., operation pedals and operation levers for rotating the rear wheels 13, 13) operated by the operator to perform travel operation of the traveling body 10, and the steering device includes a steering member (e.g., steering wheel) operated by the operator to steer the front wheels 12, 12. The work operation device includes work operation members (for example, an operation lever for operation operation of the blade 16, an operation lever for operation operation of the left and right outriggers 18, 18, an operation lever for operation operation of rotation of the rotation unit 20, and an operation lever for operation operation of the excavator device 30).

Next, with additional reference to FIG. 5 , a hydraulic control system for operating the excavator 30 (referred to as “excavator hydraulic control system”) will be described. FIG. 5 schematically shows a configuration related to hydraulic control of the swing cylinder 35, the first boom cylinder 36, the second boom cylinders 37, 37, the arm cylinder 38, and the bucket cylinder 39 associated with the excavator device 30 among the hydraulic actuators in the hydraulic excavator 1. For convenience of explanation, these hydraulic actuators in the shovel device 30 are also referred to as shovel hydraulic actuators.

As shown in FIG. 5, the excavator hydraulic control system includes an engine 61, a work hydraulic pump 62 and a pilot hydraulic pump 63 driven by the engine 61, a hydraulic oil tank 64 that stores hydraulic oil, and a control valve unit 65 that controls the supply direction and supply amount of the hydraulic oil discharged from the work hydraulic pump 62 and supplied to each excavator hydraulic actuator. The excavator hydraulic control system also includes a work operating device 41 and a controller 50 .

The control valve unit 65 has control valves corresponding to the swing cylinder 35, the first boom cylinder 36, the second boom cylinders 37, 37, the arm cylinder 38 and the bucket cylinder 39, respectively. Among these control valves, the control valves corresponding to the first boom cylinder 36, the arm cylinder 38, and the bucket cylinder 39 are pilot-operated switching valves whose spool movements are operated by pilot oil supplied from the pilot hydraulic pump 63 via the work operation device 41. On the other hand, the control valves corresponding to the swing cylinder 35 and the second boom cylinders 37, 37, respectively, are electromagnetic pilot switching valves composed of a pilot valve electromagnetically operated by an operation signal from the controller 50, and a main valve whose spool movement is operated by pilot oil supplied from the pilot hydraulic pump 63 via the work operating device 41 and the pilot valve.

The work operation device 41 supplies the pilot oil supplied from the pilot hydraulic pump 63 to the corresponding control valve in the control valve unit 65 according to the operation amount of the work operation member (the operation lever for operating the shovel device 30). Further, the work operation device 41 outputs an electric signal to the controller 50 according to the operation amount of the work operation member when the swing cylinder 35 or the second boom cylinders 37, 37 are operated. The controller 50 outputs an operation control signal to the corresponding control valve (pilot valve) in the control valve unit 65 according to the input signal from the work operation device 41 to control the movement of the pilot valve.

As described above, in the excavator hydraulic control system, the corresponding control valves in the control valve unit 65 are operated and controlled by the pilot oil supplied to the control valve unit 65 according to the operation state of the work operation member of the work operation device 41, or by the pilot oil and the operation control signal output from the controller 50. By controlling the operation of this control valve, the direction and flow rate of the hydraulic oil supplied from the work hydraulic pump 62 to each excavator hydraulic actuator via the control valve unit 65 are controlled, and the corresponding excavator hydraulic actuator expands and contracts, thereby operating the excavator device 30.

Next, a detailed configuration of the link mechanism 80 will be described with additional reference to FIGS. 6 to 18. FIG. As shown in FIGS. 6 to 8, the link mechanism 80 includes a pair of left and right first link members 81A and 81B, and a second link member . The structure of these link members 81A, 81B, and 82 will be described below, but prior to that, the structure of the bucket cylinder 39 will be briefly described. The left first link member 81A and the right first link member 81B are collectively referred to as the first link member 81 (see FIGS. 6 and 7).

The bucket cylinder 39, as shown in FIGS. 6 and 7, comprises a cylinder tube 39a and a piston rod 39b. As shown in FIG. 18, a cylindrical pin receiving portion 39c is provided at the base end of the cylinder tube 39a, and is pivotally connected to the arm 34 so as to be vertically swingable by a fifth pivot pin P5 (see FIGS. 6 and 7) inserted through a pin pivoting hole 39d of the pin receiving portion 39c. As shown in FIG. 18, a cylindrical pin receiving portion 39e is provided at the tip of the piston rod 39b, and is pivotally connected to the first link member 81 (left first link member 81A and right first link member 81B) by a sixth pivot pin P6 (see FIGS. 6 to 8) inserted through a pin connection hole 39f of the pin receiving portion 39e.

As shown in FIG. 17, the second link member 82 includes a trapezoidal base plate 82a, a cylindrical pin receiving portion 82c provided at one end of the base plate 82a (the end near the bucket bracket 72), and a similarly cylindrical pin receiving portion 82e provided at the other end of the base plate 82a (the end near the first link member 81). One end of the second link member 82 is pivotally connected to the bucket bracket 72 by means of a seventh pivot pin P7 (see FIGS. 6 to 8) inserted into the pin pivot hole 82d of the pin receiving portion 82c. The second link member 82 is pivotally connected to the first left link member 81A and the first right link member 81B at the other end thereof so as to be vertically swingable by an eighth pivot pin P8 (see FIGS. 6 to 8) inserted into the pin pivot hole 82f of the pin receiving portion 82e.

The first left link member 81A and the first right link member 81B are configured to be substantially mirror-symmetrical to each other in the left-right direction, and each component has substantially the same function. Therefore, the left first link member 81A and the right first link member 81B will be explained mainly with respect to the left first link member 81A, and the right first link member 81B will be explained supplementarily. Components that are functionally common to the first left link member 81A and the first right link member 81B are denoted by common reference numerals.

As shown in FIGS. 9 to 12, the left first link member 81A mainly includes a base plate 81a having a narrow width at one end (base end) and a wide width at the other end (distal end). The base end of the base plate 81a is formed with one pin pivot hole 81b penetrating in the lateral direction (thickness direction of the base plate 81a), and the tip of the base plate 81a is formed with three pin pivot holes 81c, 81d, and 81e penetrating in the lateral direction. As shown in FIG. 8, a ninth pivot pin P9 is inserted through the pin pivot hole 81b, and an eighth pivot pin P8 is inserted through the pin pivot hole 81c. Moreover, one of these is selected and the sixth pivot pin P6 is inserted through the pin pivot holes 81d and 81e. The pin pivot holes 81d and 81e are arranged so as to satisfy predetermined positional conditions. This position condition will be described later in detail.

As shown in FIG. 9, the inner surface of the base plate 81a (the surface facing the left side surface of the arm 34) is provided with a pin guide portion 81f formed in a cylindrical shape along the edge of the pin pivot hole 81c, and a pin guide portion 81g formed in a figure 8 shape in which two cylinders are connected along the edges of the pin pivot holes 81d and 81e. As shown in FIG. 8, the outer surface of the base plate 81a (the surface opposite to the inner surface of the base plate 81a) is provided with cylindrical pinning portions 81h, 81i, 81j, and 81k along the edges of the pin pivot holes 81b, 81c, 81d, and 81e. Each of the pinning portions 81h, 81i, 81j, 81k is provided with a locking pin hole 81m (see FIG. 11) into which a locking pin (not shown) is inserted to prevent the pivot pin inserted through the pin connecting hole 81b, 81c, 81d, 81e from coming off.

As shown in FIG. 9, the left first link member 81A has two stopper insertion holes 81p and 81q penetrating in the left-right direction at the tip of the base plate 81a. These stopper insertion holes 81p and 81q are configured so that a stopper member 83 (see FIG. 8) is inserted therethrough when performing a pivoting position switching operation, which will be described later. As shown in FIG. 8, the stopper member 83 is formed in a U shape as a whole by two stopper arm portions 83a and 83b extending parallel to each other and a connecting portion 83c connecting the base ends of the stopper arm portions 83a and 83b. The stopper member 83 is used by inserting the stopper arms 83a and 83b into the stopper insertion holes 81p and 81q, respectively. Specifically, it is possible to insert the stopper arm portion 83a into the stopper insertion hole 81p and insert the stopper arm portion 83b into the stopper insertion hole 81q for use, or to insert the stopper arm portion 83a into the stopper insertion hole 81q and insert the stopper arm portion 83b into the stopper insertion hole 81p. For convenience of explanation, the stopper arm portion 83a is inserted into the stopper insertion hole 81p, and the stopper arm portion 83b is inserted into the stopper insertion hole 81q. Further, the stopper member 83 is used only when performing a pivoting position switching operation, which will be described later, and is housed in a predetermined place such as the inside of the operator's cabin 25 at other times.

As shown in FIGS. 10 and 12, the left first link member 81A has one side edge portion on the base end side of the base plate 81a that is linearly formed, and this linearly formed portion is configured as a posture confirmation positioning portion 81r. This posture confirmation alignment portion 81r is provided so that it is possible to visually confirm whether or not the left first link member 81A (the first link member 81) is positioned in the reference posture with respect to the arm 34 when performing the later-described pivoting position switching operation. The reference posture refers to the posture of the first link member 81 with respect to the arm 34 when the first link member 81 and the arm 34 are viewed from the direction perpendicular to the outer surface of the base plate 81a (horizontal direction), and the alignment portion 81r for posture confirmation is parallel to the lower surface 34a of the arm 34 (see FIG. 7).

As shown in FIGS. 13 to 16, the right first link member 81B has a configuration that is substantially mirror-symmetrical in the left-right direction with respect to the left first link member 81A. That is, the right first link member 81B is mainly composed of a base plate 81a mirror-symmetrical to the base plate 81a of the left first link member 81A. One pin pivot hole 81b is formed at the base end of the base plate 81a, and three pin pivot holes 81c, 81d, 81e and two stopper insertion holes 81p, 81q are formed at the tip of the base plate 81a. As shown in FIG. 16, the inner surface of the base plate 81a (the surface facing the right side surface of the arm 34) is provided with a cylindrical pin guide portion 81f formed along the edge of the pin pivot hole 81c, and a figure 8-shaped pin guide portion 81g formed along the edges of the pin pivot holes 81d and 81e. In addition, a linearly formed posture confirmation alignment portion 81r is provided on one side edge portion on the base end side of the base plate 81a of the right first link member 81B.

On the other hand, in the left first link member 81A, cylindrical pinning portions 81h, 81i, 81j, and 81k (see FIG. 8) are provided on the outer surface of the base plate 81a, whereas in the right first link member 81B, such cylindrical pinning portions are not provided on the outer surface of the base plate 81a. This point is the main difference in configuration between the right first link member 81B and the left first link member 81A.

The first link member 81 (left first link member 81A and right first link member 81B) configured in this manner is pivotally connected at its proximal end to the arm 34 via a ninth pivot pin P9 so as to be vertically swingable. Specifically, as shown in FIG. 8, the arm 34 is formed with a pin pivot hole 34b that penetrates in the left-right direction. connect.

The tip of the first link member 81 is pivotally connected to the second link member 82 through an eighth pivot pin P8 so as to be capable of swinging up and down. Specifically, as shown in FIG. 8, the eighth pivot pin P8 is inserted through the pin pivot hole 81c of the right first link member 81B, the pin pivot hole 82f of the pin receiving portion 82e of the second link member 82, and the pin pivot hole 81c of the left first link member 81A to pivotally connect the first link member 81 and the second link member 82.

Further, the tip of the first link member 81 is pivotally connected to the tip of the bucket cylinder 39 via a sixth pivot pin P6 so as to be able to swing vertically. Specifically, as shown in FIG. 8, the sixth pivot pin P6 is inserted through the pin pivot hole 81d of the right first link member 81B, the pin pivot hole 39f of the pin receiving portion 39e at the tip of the bucket cylinder 39, and the pin pivot hole 81d of the left first link member 81A, so that the first link member 81 and the tip of the bucket cylinder 39 can be pivotally connected. On the other hand, the sixth pivot pin P6 can be inserted through the pin pivot hole 81e of the right first link member 81B, the pin pivot hole 39f of the pin receiving portion 39e at the tip of the bucket cylinder 39, and the pin pivot hole 81e of the left first link member 81A to pivotally connect the first link member 81 and the tip of the bucket cylinder 39.

In this manner, the link mechanism 80 can selectively switch the pivoting position of the first link member 81 (left first link member 81A and right first link member 81B) pivotally connected to the tip of the bucket cylinder 39 between the pin pivot hole 81d and the pin pivot hole 81e of the first link member 81. Hereinafter, the pivoted state of the link mechanism 80 when the first link member 81 is pivotally connected to the tip of the bucket cylinder 39 through the pin pivot hole 81d is referred to as the first pivoted state, and the pivoted state of the link mechanism 80 when the first link member 81 is pivotally connected to the tip of the bucket cylinder 39 via the pin pivot hole 81e is referred to as the second pivoted state. Switching the pivoted position between the tip of the bucket cylinder 39 and the first link member 81 between the first pivoted state and the second pivoted state is referred to as pivoted position switching, and the operation of switching the pivoted position is referred to as pivoted position switching operation.

Here, how the operation performance of the tilt bucket 70 in the shovel device 30 differs between the first pivoted state and the second pivoted state will be described with additional reference to FIGS. 19 and 20. FIG. 19 shows the swing range of the tilt bucket 70 around the fourth pivot pin P4 when the link mechanism 80 is in the first pivot state, and FIG. 20 shows the swing range of the tilt bucket 70 around the fourth pivot pin P4 when the link mechanism 80 is in the second pivot state.

When the bucket cylinder 39 expands and contracts while the link mechanism 80 is in the first pivoting state, the output from the bucket cylinder 39 during the expansion and contraction is transmitted to the tilt bucket 70 via the first link member 81 and the second link member 82 as torque around the fourth pivot pin P4, and the tilt bucket 70 swings vertically with respect to the arm 34 about the fourth pivot pin P4 within the swing range shown in FIG.

When the bucket cylinder 39 expands and contracts while the link mechanism 80 is in the second pivoting state, the output from the bucket cylinder 39 during the expansion and contraction is transmitted to the tilt bucket 70 via the first link member 81 and the second link member 82 as torque around the fourth pivot pin P4, and the tilt bucket 70 swings vertically with respect to the arm 34 about the fourth pivot pin P4 within the swing range shown in FIG.

Thus, in the excavator 30, when the link mechanism 80 is in the first pivoted state (when the tip of the bucket cylinder 39 is pivotally connected to the first link member 81 through the pin pivot hole 82d), the swing range of the tilt bucket 70 corresponding to the expansion and contraction of the bucket cylinder 39 is wider than when the link mechanism 80 is in the second pivoted state (when the tip of the bucket cylinder 39 is pivotally connected to the first link member 81 through the pin pivot hole 82e). designed to be wide. On the other hand, the excavator 30 is configured such that the torque transmitted to the tilt bucket 70 when extending the bucket cylinder 39 is greater in the second pivoted state than in the first pivoted state, thereby increasing the digging force of the tilt bucket 70.

Next, with additional reference to FIGS. 21 to 31, an example of the procedure for switching the pivot position will be described. A work procedure for switching the pivoted state of the link mechanism 80 from the first pivoted state to the second pivoted state will be described below.

FIG. 21 shows a state example of the hydraulic excavator 1 (excavator device 30) when the link mechanism 80 is in the first pivoted state. This example shows a state in which the revolving body 20 faces forward and the traveling body 10 is stopped on the horizontal road surface GS. Further, in this example, the excavator 30 as a whole faces forward, and the tilt bucket 70 is kept away from the road surface GS.

In the pivotal connection position switching operation of this example, the bucket cylinder 39 is telescopically operated from the state shown in FIG. That is, the first link member 81 is vertically swung around the ninth pivot pin P9 with respect to the arm 34 by the expansion and contraction of the bucket cylinder 39, and the posture of the first link member 81 with respect to the arm 34 is adjusted so that the posture confirmation positioning portion 81r of the first link member 81 is parallel to the lower surface 34a of the arm 34 (see FIG. 22). As the posture of the first link member 81 is adjusted at this time, the tilt bucket 70 swings up and down with respect to the arm 34 around the fourth pivot pin P4. This posture adjustment may be performed, for example, by a worker (operator) while visually checking the state of the posture of the first link member 81 as the bucket cylinder 39 expands and contracts.

Next, from the state shown in FIG. 22 , the first boom cylinder 36, the second boom cylinders 37, 37 and the arm cylinder 38 are telescopically operated while maintaining the posture of the first link member 81 with respect to the arm 34 (that is, the bucket cylinder 39 is not telescopically operated). The telescopic operation causes the first boom 32, the second boom 33 and the arm 34 to swing up and down to move the tilt bucket 70 (bucket body 71) so that its bottom surface is parallel to the road surface GS and approaches the road surface GS (see FIG. 23), and further, the bottom surface is brought into contact with the road surface GS (see FIG. 24). That is, the telescopic operation of the first boom cylinder 36 vertically swings the first boom 32 about the first pivot pin P1 with respect to the excavator side bracket 31, the telescopic operation of the second boom cylinders 37, 37 vertically swings the second boom 33 about the second pivot pin P2 with respect to the first boom 32, and the telescopic operation of the arm cylinder 38 swings the arm 3.
4 is vertically swung with respect to the second boom 33 around the third pivot pin P3. As a result, the tilt bucket 70 is moved so that the bottom surface of the tilt bucket 70 contacts the road surface GS while being parallel to the road surface GS. By bringing the bottom surface of the tilt bucket 70 into contact with the road surface GS in this way, even if the pivotal connection between the bucket cylinder 39 and the first link member 81 is released in the following procedure, the tilt bucket 70 is supported by the road surface GS and does not swing up and down.

Next, in the state shown in FIG. 24, the stopper member 83 is attached to the first link member 81 (see FIGS. 24 and 25). As described above, for convenience of explanation, the stopper member 83 is attached to the first link member 81 by inserting the stopper arm portion 83a into the stopper insertion hole 81p (see FIG. 8) of the first link member 81 and inserting the stopper arm portion 83b into the stopper insertion hole 81q (see FIG. 8) of the first link member 81.

After the stopper member 83 is attached to the first link member 81, the sixth pivot pin P6 is removed from the pin pivot hole 81d of the first link member 81 (the left first link member 81A and the right first link member 81B) and the pin pivot hole 39f (see FIG. 8) of the pin receiving portion 39e of the bucket cylinder 39 (see FIG. 25). As a result, the pivotal connection between the first link member 81 and the tip of the bucket cylinder 39 is released. When the pivotal connection between the first link member 81 and the bucket cylinder 39 is released, the bucket cylinder 39 can swing up and down around the fifth pivot pin P5 (see FIG. 24) without being extended or retracted.

After releasing the pivotal connection between the first link member 81 and the tip of the bucket cylinder 39, the bucket cylinder 39 is vertically swung around the fifth pivot pin P5 (see FIG. 24) to bring the tip of the bucket cylinder 39 (pin receiving portion 39e) into contact with the stopper arm 83a of the stopper member 83. Note that the vertical swing of the bucket cylinder 39 at this time is manually performed by an operator. Also, at this time, the bucket cylinder 39 is not expanded and contracted so that the length of the bucket cylinder 39 does not change.

As outlined above, the pin pivot holes 81d and 81e of the first link member 81 (the left first link member 81A and the right first link member 81B) are arranged to satisfy predetermined positional conditions. The positional condition is that, when the bucket cylinder 39 is expanded and contracted and the first link member 81 is positioned in the reference posture with respect to the arm 34, the pin pivot hole 81d and the pin pivot hole 81e are aligned on the same circular arc centering on the pivot line (center axis line of the pin pivot hole 39d) of the base end portion (pin receiving portion 39c) of the bucket cylinder 39 and the arm 34. The radius dimension of the same circular arc is equal to the distance between the pivotal axes of both ends of the bucket cylinder 39 (the distance between the central axis of the pin pivotal hole 39d of the pin receiving portion 39c and the central axis of the pin pivotal hole 39f of the pin receiving portion 39e) when the first link member 81 is positioned in the reference posture with respect to the arm 34.

Since the pin pivot holes 81d and 81e of the first link member 81 are arranged on the same arc as described above, the bucket cylinder 39, which has been disengaged from the pin pivot hole 81d and the first link member 81 as described above, can be vertically swung about the fifth pivot pin P5. 1 (the pin pivot holes 39f and 81e are opposed to each other and their center axes are aligned).

This alignment can be easily performed by vertically swinging the bucket cylinder 39 around the fifth pivot pin P5 and bringing the pin receiving portion 39e of the bucket cylinder 39 into contact with the stopper arm portion 83a of the stopper member 83 as described above. Specifically, when the bucket cylinder 39 is vertically swung, the stopper arm 83a of the stopper member 83 contacts the pin receiving portion 39e to restrict the vertical swing of the bucket cylinder 39 when the pin pivot hole 39f of the pin receiving portion 39e faces the pin pivot hole 81e of the first link member 81, that is, when the positions of the pin pivot holes 39f and 81e are aligned. In addition, the other stopper arm 83B of the stopper member 83 is the position of both pin cigarette 39F, 81d, when the pin pins 39F of the pin receiving part 39E, which are opposed to the pin pin -portrait 81d of the first link member 81, when the bucket cylinder 39 is shaken up and down. When it is in line, it is configured to regulate the up and down swing of the bucket cylinder 39 by entering the bucket cylinder piston rod 39b.

After the pin pivot hole 39f of the pin receiving portion 39e of the bucket cylinder 39 and the pin pivot hole 81e of the first link member 81 are aligned as described above, the sixth pivot pin P6 is inserted through the pin pivot hole 81e of the first link member 81 and the pin pivot hole 39f of the pin receiving portion 39e of the bucket cylinder 39 (see FIG. 27). As a result, the first link member 81 and the tip of the bucket cylinder 39 are pivotally connected via the pin pivot hole 81 e of the first link member 81 .

After the bucket cylinder 39 is pivotally connected to the first link member 81 through the pin pivot hole 81e by the sixth pivot pin P6, the stopper member 83 is removed from the first link member 81 (see FIGS. 28 to 30). This completes the pivoting position switching operation for switching the pivoting state of the link mechanism 80 from the first pivoting state to the second pivoting state. The hydraulic excavator 1 that has completed switching can operate the excavator device 30 to perform excavation work or the like using the tilt bucket 70 (see FIG. 31). An example of the procedure of the pivot position switching operation for switching the pivoting state of the link mechanism 80 from the first pivoting state to the second pivoting state has been described above. Since the pivoting position switching operation for switching the pivoting state of the link mechanism 80 from the second pivoting state to the first pivoting state can be performed in the same procedure as described above, detailed description thereof will be omitted.

As described above, according to the excavator 30, by maintaining the first link member 81 in the reference posture with respect to the arm 34, it is possible to manually adjust (align) the pivoted position between the first link member 81 and the arm 34 when switching the pivoted position of the link mechanism 80. Therefore, it is possible to easily perform the pivotal connection position switching operation in the link mechanism 80 .

Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to the above embodiments. For example, in the above embodiment, the U-shaped stopper member 83 having two stopper arms 83a and 83b is used, but other shaped stopper members may be used. For example, it is possible to use a stopper member that is formed in a single rod shape and whose rod-shaped portion (also referred to as a “base portion”) functions as a stopper. Such a rod-shaped stopper member is used by inserting its base into the stopper insertion hole 81p of the first link member 81, for example, when aligning the tip portion (pin pivot hole 39f) of the bucket cylinder 39 with the pin pivot hole 81e of the first link member 81. Also, when aligning the tip of the bucket cylinder 39 with the pin pivot hole 81d of the first link member 81, the base is inserted through the stopper insertion hole 81q of the first link member 81 for use. Although the U-shaped stopper member 83 and the rod-shaped stopper member described above are formed to have a circular cross-section, stopper members having other cross-sectional shapes such as an L-shaped cross section may be used.

In the above embodiment, the bucket cylinder 39 and the first link member 81 are pivoted at two positions, the pin pivot hole 81d and the pin pivot hole 81e, but three or more selectable pivot positions may be provided. For example, three or more pin pivot holes that can be selectively pivoted with the tip of the bucket cylinder 39 may be provided in the first link member 81 so as to line up on the same arc as described above.

Further, in the above-described embodiment, the tilt bucket 70 is used as an attachment attached to the tip of the arm 34 so as to be capable of swinging up and down, but it is not limited to this. As attachments, ordinary buckets, breakers, crushers, cutters, auger devices, etc. may be used. In the above-described embodiment, the case where the present invention is applied to the working device (excavator device 30) of the hydraulic excavator 1 has been described.

1 Hydraulic excavator 10 Traveling body 20 Revolving body 30 Excavator device (working device)
34 Arm 39 Bucket cylinder (attachment)
39c, 39e Pin receiving portions 39d, 39f Pin pivot connection hole 41 Work operation device 50 Controller 61 Engine 62 Work hydraulic pump 63 Pilot pump 65 Control valve unit 70 Tilt bucket 80 Link mechanism 81 First link member 81A Left first link member 81B Right first link member 81b, 81c, 81d, 81e Pin pivot connection holes 81p, 81q Stopper insertion hole 82 Second link member 83 Stopper members 83a, 83b Stopper arm P3 Third pivot pin P4 Fourth pivot pin P5 Fifth pivot pin P6 Sixth pivot pin P7 Seventh pivot pin P8 Eighth pivot pin P9 Ninth pivot pin

Claims (4)

an arm that can swing up and down;
an attachment for work that can be attached to the arm so as to be vertically swingable;
a first link member having one end pivotally connected to the arm so as to be vertically swingable;
a second link member pivotally connected at one end to the attachment and at the other end to the first link member so as to be vertically swingable in a state in which the attachment is attached to the arm so as to be vertically swingable;
an attachment hydraulic cylinder whose base end is pivotally connected to the arm and whose tip end is pivotally connected to the first link member so as to be vertically swingable, and which expands and contracts to vertically swing the attachment with respect to the arm;
The first link member is provided with a plurality of pivotally connected portions capable of pivotally connecting the distal end portion of the attachment hydraulic cylinder, and the first link member and the attachment hydraulic cylinder are selectively switched among the plurality of pivotally connected portions for pivotal connection, wherein
The attachment is attached to the arm so as to be vertically swingable, one end of the second link member is vertically swingably connected to the attachment and the other end is vertically swingably connected to the first link member, and the base end of the attachment hydraulic cylinder is pivotally connected to one of the plurality of pivotally connected portions of the first link member so as to be vertically swingable,
The first link member can be vertically swung by the attachment hydraulic cylinder to position the first link member in a predetermined reference posture with respect to the arm,
The working device, wherein the first link member is positioned in the reference posture with respect to the arm, and the plurality of pivotally connected portions are arranged on the same circular arc centered on a pivotal line between the base end portion of the attachment hydraulic cylinder and the arm. 2. The working apparatus according to claim 1, wherein the first link member is provided with a posture confirmation positioning portion for visually confirming whether the first link member is positioned in the reference posture with respect to the arm. A stopper member for aligning the pivotal position of the attachment hydraulic cylinder with respect to the arm when the tip portion of the attachment hydraulic cylinder is disengaged from one of the pivoted portions to swing the attachment hydraulic cylinder about the pivot axis in a state where the first link member is positioned in the reference posture with respect to the arm, and the tip portion of the attachment hydraulic cylinder opposes the other pivoted portion in a pivotable state. Item 3. The work device according to Item 1 or 2. 4. The working device according to claim 3, wherein the stopper member can be attached to and detached from the first link member.

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