JP2009133084A - Offset boom type front device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an offset boom type front device capable of preventing a link rod from interfering with an obstacle by letting pressure oil circulate without increasing thickness of the link rod and increasing amount of offsetting to improve work efficiency. <P>SOLUTION: This offset boom type front device is constituted by forming four oil passages 26 by extending in the direction of length in a passage member 25 of the link rod 24, connecting a first hydraulic oil pipe 29 extended from a control valve device with a terminal of each oil passage 26, and connecting a second hydraulic oil pipe 30 extended into an arm cylinder 20 and a bucket cylinder 21 with a tip of each oil passage 26. Consequently, a part of a hydraulic oil line 31 for supplying and discharging pressure oil into/from each cylinder 20, 21 is provided by utilizing the link rod 24. As a result, the link rod 24 can be formed to be thin and its interference with an obstacle can be prevented. Since a large clearance can be ensured between the passage member 25 and a second boom 13, amount of offsetting of the front device 11 can be increased. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an offset boom type front device in which, for example, a bucket can be translated in the left and right directions in order to perform a side ditching operation or the like.

  In general, a hydraulic excavator includes a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and a front device that is provided so as to be able to move up and down at a front portion of the upper revolving body. It is roughly constituted by. Also, as a front device of a hydraulic excavator, an offset boom type front device is known, and this front device uses a offset cylinder or the like to translate a work tool such as a bucket in the left and right directions, thereby Excavation work such as a gutter can be performed on the left or right side of the traveling body.

  Here, the offset boom type front device has a first boom whose base end side is attached to the upper swing body so as to be able to move up and down, and is pin-coupled to the distal end side of the first boom so as to swing left and right. A second boom, a third boom that is pin-coupled to the front end side of the second boom so as to swing leftward and rightward, an arm that is rotatably attached to the front end side of the third boom, A bucket attached to the distal end side of the arm, and attached between the first boom and the third boom, and when the second boom is swung with respect to the first boom, the third boom is moved to the second boom. And a link rod that translates the third boom in the left and right directions by swinging to the opposite side.

  Further, the offset boom type front device includes a boom cylinder that moves the first boom up and down, an arm cylinder that rotates the arm, a bucket cylinder that rotates the bucket, and an offset that swings the second boom relative to the first boom. A cylinder or the like is provided. These hydraulic cylinders are connected to a hydraulic power source provided in the upper swing body through a plurality of hydraulic pipes including hydraulic pipes, hydraulic hoses and the like. Further, among the plurality of hydraulic pipes connected to each hydraulic cylinder, the hydraulic pipe for supplying and discharging pressure oil to and from the arm cylinder and the bucket cylinder has a third boom extending along the side surfaces of the first boom and the second boom. It extends to the side.

  On the other hand, in the offset boom type front device, a link rod is formed in a cylindrical shape, and a plurality of hydraulic pipes are passed through the cylindrical link rod, thereby extending along the second boom of the hydraulic pipes. There is one that prevents damage to the part and has a good appearance (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 11-50486

  By the way, in the prior art by patent document 1 mentioned above, since the link rod is formed in the shape of a rectangular tube and a plurality of hydraulic pipes are passed through the link rod, the link rods are used in order to secure a space through which each hydraulic pipe passes. Becomes larger (thicker). For this reason, there exists a problem that a link rod interferes with an obstruction and is damaged.

  In addition, when the link rod is thickened, the gap between the second boom and the link rod is reduced, so that when the second boom is swung greatly, the link rod comes into contact with the side surface of the second boom. For this reason, there is a problem that the offset amount of the front device is reduced and workability is lowered.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to prevent the link rod from interfering with an obstacle by circulating pressure oil without increasing the thickness of the link rod. Another object is to provide an offset boom type front device that can improve workability by increasing the amount of offset.

  An offset boom type front apparatus according to the present invention includes a first boom that is attached to a vehicle body at a proximal end side and moves up and down by a boom cylinder, and a first boom that is attached to a distal end side of the first boom and swings left and right by the offset cylinder. Two booms, a third boom attached to the distal end side of the second boom so as to be swingable leftward and rightward, an arm attached to the distal end side of the third boom and rotated by an arm cylinder; A work tool that is attached to the distal end side of the first boom and that is rotated by a work tool cylinder; and the third boom that is attached between the first boom and the third boom and the second boom is swung relative to the first boom. A link rod that swings the boom to the opposite side of the second boom is provided.

  In order to solve the above-described problem, a feature of the configuration adopted by the invention of claim 1 is that the link rod is formed of a rigid material having rigidity in a thrust direction, and the arm cylinder and In another aspect of the present invention, a passage member provided with an oil passage for supplying and discharging pressure oil to and from the work tool cylinder is used.

  According to the invention of claim 2, the link rod is located on one end side in the length direction and is pin-coupled to the first boom, and is located on the other end side in the length direction. And a third boom side mounting portion that is pin-coupled to the third boom, and the passage member provided between the mounting portions.

  According to the invention of claim 3, the link rod is formed by using one passage member extending along the second boom, and a plurality of oil passages are provided in the one passage member. There is.

  According to a fourth aspect of the present invention, the link rod is formed using a plurality of passage members extending along the second boom, and each passage member is provided with the oil passage.

  According to the first aspect of the present invention, a passage member made of a rigid material having rigidity in the thrust direction is used for the link rod, and the arm cylinder and / or the work tool cylinder is pressed inside the passage member. An oil passage for supplying and discharging oil is provided. Accordingly, the pressure oil can be supplied to and discharged from the arm cylinder and / or the work tool cylinder using the oil passage of the passage member constituting the link rod.

  In this way, when a passage member with an oil passage provided in the link rod is used, the link rod is not required for the space for passage of the pipe as compared with the case where the hydraulic pipe is passed through the cylindrical link rod. (Passage member) It can be formed thin.

  As a result, the overhang of the link rod can be kept small, and the link rod can be prevented from interfering with an obstacle. Moreover, since a large gap can be secured between the link rod and the second boom, the second boom can be swung at a large angle, and the offset amount of the front device can be increased to improve workability. . Further, by providing the oil passage directly in the passage member, the number of parts can be reduced, and the assembling workability can be improved.

  According to invention of Claim 2, the 1st boom side attaching part located in the one end side of the length direction of a link rod is pin-coupled to the 1st boom, and the 3rd boom side located in the other end side of a length direction By pin coupling the attachment portion to the third boom, the link rod can connect the first boom and the third boom by a passage member between the attachment portions.

  According to the invention of claim 3, a single passage member extending along the second boom is used for the link rod, and the passage member is provided with a plurality of oil passages therein. Thereby, a link rod can be formed with a small number of parts. Even when the passage member is formed thin, the passage member can have a large cross-sectional area at a portion other than the oil passage, and can be formed with sufficiently high rigidity.

  According to the invention of claim 4, a plurality of passage members extending along the second boom are used for the link rod, and these passage members are provided with oil passages therein. Thereby, for example, by bundling existing metal pipes and using them as passage members, the link rod can be formed with a simple structure, and the manufacturing cost can be reduced.

  Hereinafter, as a construction machine provided with an offset boom type front device according to an embodiment of the present invention, a hydraulic excavator will be described as an example and described in detail with reference to the accompanying drawings.

  First, FIG. 1 to FIG. 7 show a first embodiment of the present invention. In the first embodiment, the link rod is formed by using one passage member extending along the second boom, and a case where a plurality of oil passages are provided in one passage member will be described. .

  In FIG. 1, reference numeral 1 denotes a hydraulic excavator as a typical example of a construction machine. The hydraulic excavator 1 includes a self-propelled crawler-type lower traveling body 2, an upper revolving body 3 that is turnably mounted on the lower traveling body 2, and an up-and-down motion on the front side of the upper revolving body 3. This is generally constituted by an offset boom type front device 11 which will be described later. The lower traveling body 2 and the upper turning body 3 constitute a vehicle body of the present invention.

  Here, the upper swing body 3 is provided on the lower left side of the swing frame 4 which is a base provided on the lower traveling body 2 so as to be swingable. Various mounts such as an engine, a hydraulic pump, and a control valve device (all not shown) mounted on the revolving frame 4 and positioned behind the cab 5 An exterior cover 6 that covers the device and a counterweight 7 that is provided at the rear end of the revolving frame 4 and balances the weight with the front device 11 described later are configured.

  Next, the offset boom type front device 11 provided on the front side of the excavator 1 and moving the arm 17 and the bucket 18 in the left and right directions will be described.

  Reference numeral 11 denotes an offset boom type front device which is located on the right side of the cab 5 and is provided on the front side of the upper swing body 3 so as to be able to move up and down. The front device 11 is suitably used for excavation work such as a gutter. Here, as shown in FIG. 2 and the like, the front apparatus 11 includes a first boom 12, a second boom 13, a third boom 15, an arm 17, a bucket 18, cylinders 19, 20, 21, 23, links, which will be described later. It is comprised by the rod 24 grade | etc.,.

  Reference numeral 12 denotes a first boom attached to the front side of the revolving frame 4 so as to be able to move up and down. The first boom 12 is formed as an elongated hollow structure whose front end side is bent in a substantially heft shape. Here, the base end side of the first boom 12 is pin-coupled to a boom mounting bracket (not shown) of the revolving frame 4 so as to be rotatable. Further, a bifurcated mounting bracket 12A spaced upward and downward is provided on the distal end side of the first boom 12 so as to protrude forward, and the proximal end side of the second boom 13 described later is provided on the mounting bracket 12A. It is configured to be pin-coupled.

  Further, as shown in FIG. 3, three mounting plates 12B, 12C, and 12D are provided on the left side surface on the distal end side of the first boom 12 so as to protrude outward at a predetermined interval in the upward and downward directions. One end of a link rod 24 described later is pin-coupled between the upper and intermediate mounting plates 12B and 12C, and the bottom side of the offset cylinder 23 described later is pinned between the intermediate and lower mounting plates 12C and 12D. Are combined.

  A second boom 13 is connected to the front end side of the first boom 12 so as to be swingable leftward and rightward. The second boom 13 is formed as a strong hollow structure having a rectangular tube shape. Further, a proximal end boss 13A having a substantially cylindrical shape is provided on the proximal end side (the first boom 12 side) of the second boom 13, and the proximal end boss 13A is a mounting bracket 12A of the first boom 12. In addition, the first vertical pin 14 is pin-coupled so as to be swingable leftward and rightward (horizontal direction).

  On the other hand, a tip end boss 13B having a substantially cylindrical shape is also provided on the tip end side of the second boom 13, and a mounting bracket 15A of a third boom 15 described later is pin-coupled to the tip end boss 13B. It has become. Further, a cylinder mounting plate 13C is provided on the left side surface of the second boom 13 so as to be located on the tip side, and a rod side of an offset cylinder 23 described later is mounted on the cylinder mounting plate 13C.

  A third boom 15 is connected to the distal end side of the second boom 13 so as to be swingable leftward and rightward. The third boom 15 is formed as a strong hollow structure having a rectangular tube shape. Further, a mounting bracket 15A is formed on the base end side of the third boom 15 by being recessed in a U-shape, and the mounting bracket 15A uses the second vertical pin 16 to connect the front end side of the second boom 13. The boss 13B is pin-coupled so as to be swingable leftward and rightward (horizontal direction).

  On the other hand, a cylinder mounting portion 15B is provided on the base end side of the third boom 15 so as to protrude to the opposite side (front side) of the mounting bracket 15A. The cylinder mounting portion 15B has a bottom of an arm cylinder 20 described later. The side is pivotally mounted. Further, a pair of upper and lower link mounting plates 15C are provided on the left side surface of the third boom 15 on the base end side, and a third boom side mounting eye of a link rod 24 described later is provided on the link mounting plate 15C. 28 is attached.

  Here, the first boom 12, the second boom 13, and the third boom 15 constitute a parallel link mechanism (a parallelogram-shaped connection state) in cooperation with a link rod 24 described later. Thus, when the second boom 13 is swung left and right with respect to the first boom 12, the second boom 13 is swung with the same angle on the opposite side to the direction in which the second boom 13 is swung with respect to the first boom 12. By swinging the third boom 15 with respect to the second boom 13, the first boom 12 and the third boom 15 are always in a parallel state.

  Reference numeral 17 denotes an arm (see FIG. 2) rotatably attached to the distal end side of the third boom 15. The arm 17 is a solid hollow structure having a rectangular tube shape like the first boom 12 and the like. Is formed. The base end side of the arm 17 is pin-coupled to the distal end portion of the third boom 15 so as to be rotatable upward and downward. A cylinder mounting plate 17A protrudes from the base end side of the arm 17, and a rod side of an arm cylinder 20 (to be described later) and a bottom side of the bucket cylinder 21 are pin-coupled to the cylinder mounting plate 17A.

  Reference numeral 18 denotes a bucket as a working tool that is rotatably attached to the tip of the arm 17. The bucket 18 is in the form of one of a plurality of types of attachments that are selectively attached according to the work performed by the front device 11.

  A boom cylinder 19 is provided between the upper swing body 3 and the first boom 12. The boom cylinder 19 moves the first boom 12 up and down with respect to the revolving frame 4. The boom cylinder 19 is pivotally attached to the revolving frame 4 at the bottom side, which is the base end side, and is attached to the lower end of the mounting bracket 12A at the distal end side of the rod.

  Reference numeral 20 denotes an arm cylinder provided between the third boom 15 and the arm 17. The arm cylinder 20 is attached to the cylinder mounting portion 15B of the third boom 15 at the bottom side, which is the base end side, and is attached to the cylinder mounting plate 17A of the arm 17 at the distal end side of the rod.

  Reference numeral 21 denotes a bucket cylinder as a work implement cylinder. The bucket cylinder 21 is attached to the cylinder mounting plate 17A of the arm 17 on the bottom side, which is the base end side, and the tip end side of the rod is connected to the bucket 18 via the bucket link 22. Has been.

  Reference numeral 23 denotes an offset cylinder provided between the first boom 12 and the second boom 13. The bottom side of the offset cylinder 23 is attached to the mounting plates 12C and 12D of the first boom 12, and the distal end side of the rod is attached to the cylinder mounting plate 13C of the second boom 13. As a result, the offset cylinder 23 swings the second boom 13 leftward and rightward relative to the first boom 12 by reducing and extending the rod. At this time, the third boom 15 can be translated (offset) in the left and right directions by a parallel link structure using a link rod 24 described later.

  Next, the link rod 24 that is a characteristic part of the first embodiment provided between the first boom 12 and the third boom 15 will be described.

  Reference numeral 24 denotes a link rod provided in the front device 11. The link rod 24 moves the third boom 15 in parallel with respect to the first boom 12, and forms a parallel link mechanism in cooperation with the first boom 12, the second boom 13, and the third boom 15. Yes. At the same time, the link rod 24 is a hydraulic line for supplying and discharging pressure oil from a control valve device serving as a hydraulic pressure source provided in the upper swing body 3 to and from the arm cylinder 20 and bucket cylinder 21 on the third boom 15 side. Part of 31 is also configured. The link rod 24 is roughly constituted by a passage member 25, oil passages 26, and mounting eyes 27 and 28, which will be described later.

  Reference numeral 25 denotes a single passage member constituting the main body portion of the link rod 24. The passage member 25 is formed in a long cylindrical shape using a rigid material having rigidity in the axial thrust direction, for example, a metal material such as iron or aluminum alloy, or a reinforced resin material such as FRP. It extends in parallel with the boom 13. The passage member 25 is provided with mounting eyes 27 and 28 described later at both ends in the axial direction (length direction).

  As shown in FIGS. 5 and 6, the passage member 25 is provided with two rows of hose connection seats 25 </ b> A that are wide in the diameter direction on both sides in the length direction. Also, one hose connection seat 25A is provided with two screw holes 25B (only one is shown), whereby four first hydraulic pipes 29 to be described later are provided on one end side of the passage member 25. Four second hydraulic pipes 30 to be described later can be connected to the other end side of the passage member 25, and pressure oil can be supplied to and discharged from the arm cylinder 20 and the bucket cylinder 21. .

  Reference numeral 26 denotes a plurality of, for example, four oil passages provided inside the passage member 25, and each oil passage 26 is formed to extend in parallel to the length direction of the passage member 25. Further, each of the oil passages 26 is provided at intervals of 90 degrees in the circumferential direction of the passage member 25 (see FIG. 7) so that, for example, pressure oil can be supplied to and discharged from the arm cylinder 20 and the bucket cylinder 21 (going back and returning). It is arranged.

  Here, each oil passage 26 is directly inserted into the cylindrical passage member 25 as shown in FIG. In addition, the end of each oil passage 26 opens at the bottom of a screw hole 25 </ b> B formed in each hose connection seat 25 </ b> A of the passage member 25.

  In this way, each oil passage 26 is directly drilled in the passage member 25, so that the passage member 25 is not provided with a space for passage of the hydraulic piping as compared with the case where the hydraulic piping is passed through. It can be formed thin. Moreover, since the four oil passages 26 are formed in one passage member 25, even when the passage member 25 is formed thin, a large cross-sectional area can be obtained in a portion other than each oil passage 26, Sufficient rigidity can be obtained. Furthermore, since the passage member 25 is formed to be thin, interference with an obstacle can be prevented and a large gap can be secured between the passage member 25 and the left side surface of the second boom 13. It can swing at a large angle, and the offset amount of the front device 11 can be increased.

  Reference numeral 27 denotes a first boom side mounting eye as a first boom side mounting portion provided on one end side in the length direction of the passage member 25. As shown in FIGS. 3 and 4, the first boom side mounting eye 27 is pin-coupled between the mounting plates 12 </ b> B and 12 </ b> C of the first boom 12 via a connecting pin 27 </ b> A.

  On the other hand, 28 is a third boom side mounting eye as a third boom side mounting portion provided on the other end side in the length direction of the passage member 25. The third boom side attachment eye 28 is pin-coupled to the link attachment plate 15C of the third boom 15 via a connection pin 28A.

  As a result, the link rod 24 can connect the first boom 12 and the third boom 15 at predetermined intervals using the mounting eyes 27 and 28, and the third boom 15 can always be connected to the first boom 12. A parallel link mechanism for maintaining a parallel state is formed in cooperation with the first boom 12, the second boom 13, and the third boom 15.

  Reference numeral 29 denotes a plurality of, for example, four first hydraulic pipes provided along the first boom 12, each of the hydraulic pipes 29 for supplying and discharging pressure oil to and from the arm cylinder 20 and the bucket cylinder 21. It is. Each first hydraulic pipe 29 has one end connected to the control valve device of the upper swing body 3 and the other end connected to a screw hole 25 </ b> B provided on the base end side of the passage member 25 constituting the link rod 24. Has been.

  Reference numeral 30 denotes a plurality of, for example, four second hydraulic pipes provided along the third boom 15, and two of the hydraulic pipes 30 are paths in which one end constitutes the link rod 24. The member 25 is connected to a screw hole 25 </ b> B provided on the distal end side, and the other end is connected to the arm cylinder 20. The other two are connected at one end to a screw hole 25 </ b> B provided on the distal end side of the passage member 25 and connected at the other end to the bucket cylinder 21.

  Here, the first hydraulic pipe 29, the oil passage 26 of the link rod 24, and the second hydraulic pipe 30 are for supplying and discharging pressure oil to and from the arm cylinder 20 and bucket cylinder 21 on the third boom 15 side. A hydraulic line 31 is configured. For the hydraulic pipes 29 and 30, for example, metal pipes and flexible hoses are used according to the fixed part and the movable part.

  Reference numeral 32 denotes two offset cylinder hydraulic pipes provided along the first boom 12. Each of the hydraulic pipes 32 supplies and discharges pressure oil to and from the offset cylinder 23. The boom cylinder 19 is connected to a boom cylinder hydraulic pipe (not shown).

  The hydraulic excavator 1 according to the first embodiment has the above-described configuration, and a case will be described in which a side groove excavation work or the like is performed using the offset boom type front device 11 mounted on the hydraulic excavator 1.

  First, the offset cylinder 23 is operated to swing the second boom 13 left and right with respect to the first boom 12. At this time, since the first boom 12, the second boom 13, the third boom 15, and the link rod 24 form a parallel link mechanism, the third boom 15, the arm 17, and the bucket 18 are connected to the left or right side of the upper swing body 3. Can be translated (offset).

  When the excavation position is determined, pressure oil is supplied from the control valve device of the upper swing body 3 through the first hydraulic pipe 29, the oil passage 26 of the link rod 24, the second hydraulic pipe 30 (hydraulic line 31), and the like. By feeding and discharging, the boom cylinder 19, arm cylinder 20, bucket cylinder 21, etc. can be expanded and contracted to operate the first boom 12, arm 17, bucket 18, etc., and excavate the side grooves.

  Here, according to the first embodiment, the link rod 24 is formed of a rigid material having rigidity with respect to the thrust direction which is the length direction, such as a metal material, and the arm cylinder 20, The passage member 25 provided with four oil passages 26 for supplying and discharging pressure oil to and from the bucket cylinder 21 is used. Therefore, the first hydraulic pipe 29 extending from the control valve device of the upper swing body 3 is connected to the base end of each oil passage 26 of the passage member 25, and the arm cylinder 20 and the bucket cylinder 21 extend to the tip of each oil passage 26. The second hydraulic pipe 30 can be connected.

  Thereby, a part of the hydraulic line 31 for supplying and discharging pressure oil to and from the arm cylinder 20 and the bucket cylinder 21 of the front device 11 can be provided by using the link rod 24. In this way, when each oil passage 26 is formed in the link rod 24, as in Patent Document 1, compared to a link rod through which hydraulic piping is passed, a link rod is provided by an amount that does not require a space for passage through the piping. The 24 passage members 25 can be formed thin.

  As a result, since the projecting dimension of the link rod 24 can be kept small, the link rod 24 can be prevented from interfering with an obstacle, and workability, life and the like can be improved. In addition, when the link rod 24 is formed thin, a large gap can be secured between the link rod 24 and the second boom 13, so that the second boom 13 can be swung at a large angle, and the front device 11 can be increased to improve workability. Further, by integrating the link rod 24 and the hydraulic line 31, the number of parts can be reduced and the assembly workability can be improved.

  In addition, the first boom side mounting eye 27 located on one end side in the length direction of the link rod 24 is pin-coupled to the first boom 12, and the third boom side mounting eye 28 located on the other end side in the length direction is connected. By pin coupling to the third boom 15, both end sides of the passage member 25 of the link rod 24 are rotatably connected to the first boom 12 and the third boom 15 via the mounting eyes 27 and 28. Can do.

  In addition, since each oil passage 26 is directly drilled in the passage member 25 that forms the link rod 24, even if the passage member 25 is formed thin, a large cross-sectional area is formed by a portion other than each oil passage 26. And sufficient strength to construct a parallel link mechanism can be obtained.

  Further, in the first embodiment, the four oil passages 26 are formed in one passage member 25 so as to extend in parallel to the length direction thereof, thereby providing a link including the four oil passages 26. A rod 24 can be formed. Therefore, the high-strength link rod 24 can be formed with a small number of parts.

  Next, FIGS. 8 to 12 show a second embodiment of the present invention. The feature of this embodiment is that the link rod is formed using a plurality of passage members extending along the second boom, and each passage member is provided with an oil passage. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  8 and 9, reference numeral 41 denotes a link rod according to the second embodiment provided in the front device 11. The link rod 41 moves the third boom 15 in parallel with respect to the first boom 12, and forms a parallel link mechanism in cooperation with the first boom 12, the second boom 13, and the third boom 15. Yes. At the same time, the link rod 41 also includes a part of a hydraulic line 44 to be described later for supplying and discharging the pressure oil from the control valve device of the upper swing body 3 to the arm cylinder 20 and the bucket cylinder 21 on the third boom 15 side. It is composed. The link rod 41 is roughly constituted by a passage member 42, oil passages 43, attachment eyes 45 and 46, and a binding tool 47, which will be described later.

  Reference numeral 42 denotes a plurality of, for example, four passage members constituting the main body portion of the link rod 41, and each passage member 42 extends substantially parallel to each other along the left side of the second boom 13. In addition, each passage member 42 is formed with sufficient rigidity by bundling four long pipe materials made of a metal material such as iron or aluminum alloy, or a reinforced resin material such as FRP with a binding tool 47 described later. Has been. Each passage member 42 made of a metal pipe material or the like has an oil passage 43 described later. Further, each passage member 42 extends in parallel in a slightly bent state so as to restrict the intermediate portion in the length direction to be bound so that the binding tool 47 does not protrude to the periphery.

  Reference numeral 43 denotes a plurality of, for example, four oil passages formed in each passage member 42. Each oil passage 43 extends in the length direction inside the passage member 42, and one end thereof is a first boom side described later. The bottom of the screw hole 45B of the mounting eye 45 is opened, and the other end is opened at the bottom of the screw hole 46B of the third boom side mounting eye 46. And each oil path 43 can be simply provided in the inside by forming the channel | path member 42 from a pipe material. Each oil passage 43 forms a hydraulic line 44 by the first hydraulic pipe 29 and the second hydraulic pipe 30.

  Reference numeral 45 denotes a first boom side mounting eye as a first boom side mounting portion provided on one end side in the length direction of each passage member 42. As shown in FIGS. 8 and 9, the mounting eye 45 has a circular distal end side pin-connected between the mounting plates 12 </ b> B and 12 </ b> C of the first boom 12 via a connecting pin 45 </ b> A. On the other hand, the base end side of the first boom-side mounting eye 45 is formed in a rectangular parallelepiped shape, and as shown in FIG. 10, four passage members 42 are inserted into the end face, and are integrally formed using, for example, welding means. It is fixed to. In addition, four screw holes 45B (only two are shown) are provided at predetermined intervals on the upper surface on the base end side of the mounting eye 45, and the first screw holes 45B have a first interval as shown in FIG. Four hydraulic pipes 29 can be connected.

  On the other hand, 46 is a third boom side mounting eye serving as a third boom side mounting portion provided on the other end side of each passage member 42 and located on the opposite side of the first boom side mounting eye 45. The attachment eye 46 is pin-coupled to the link attachment plate 15C of the third boom 15 via a connection pin 46A at the circular distal end side. On the other hand, the base end side of the third boom side mounting eye 46 formed in the shape of a rectangular parallelepiped is welded with four passage members 42 inserted into the end face, similarly to the first boom side mounting eye 45. Also, four screw holes 46B (only two are shown) are provided on the upper surface of the base end side of the mounting eye 46, and four second hydraulic pipes 30 can be connected to these screw holes 46B. .

  Thereby, the four passage members 42 and the mounting eyes 45 and 46 can connect the mounting plates 12B and 12C of the first boom 12 and the link mounting plate 15C of the third boom 15 at a predetermined interval. A parallel link mechanism for keeping the third boom 15 in parallel with the first boom 12 is formed in cooperation with the first boom 12, the second boom 13, and the third boom 15.

  A binding tool 47 is provided at an intermediate portion in the length direction of each passage member 42. As shown in FIG. 12, the binding tool 47 is for positioning and fixing each passage member 42 by inserting it into a disk-shaped plate body. For example, two binding tools 47 are provided apart from each other in the length direction of each passage member 42. One or three or more binding members 47 may be provided according to the length of each passage member 42.

  Thus, also in the second embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the first embodiment described above. In particular, in the link rod 41 according to the second embodiment, four passage members 42 made of a metal material, a reinforced resin material, or the like are provided so as to extend in parallel, and oil passages 43 are formed in the passage members 42, respectively. Since it is set as the structure, the link rod 41 can be formed, for example using the existing metal piping etc., and manufacturing cost can be reduced. Moreover, since the intermediate part of the length direction of each channel | path member 42 is bundled fixedly by each binding tool 47, the intensity | strength of the link rod 41 can be raised.

  In the first embodiment, a case where four oil passages 26 are provided in the passage member 25 constituting the link rod 24 is illustrated, and in the second embodiment, four links constituting the link rod 41 are illustrated. The case where the oil passage 43 is provided in each of the passage members 42 is illustrated. However, the present invention is not limited thereto, and two oil passages or six oil passages may be provided on the link rod, and the number of oil passages is not limited.

  In the first embodiment, the case where the pressure oil supplied to and discharged from the arm cylinder 20 and the bucket cylinder 21 is circulated through the oil passage 26 of the link rod 24 has been described as an example. However, the present invention is not limited to this, and the configuration may be such that the pressure oil supplied to and discharged from either the arm cylinder 20 or the bucket cylinder 21 is circulated through the oil passage 26 of the link rod 24. Moreover, it is good also as a structure which distribute | circulates the pressure oil supplied and discharged to actuators other than the arm cylinder 20 and the bucket cylinder 21, for example, a vibration exciter, a pile driver, an earth drill, etc. with the oil path 26. These configurations can be similarly applied to the second embodiment.

  Furthermore, in each embodiment, the case where the offset boom type front device 11 is provided in the hydraulic excavator 1 provided with the crawler type lower traveling body 2 has been described as an example. However, the present invention is not limited to this, and can be applied to, for example, a wheel-type hydraulic excavator as long as the machine includes an offset boom type front device.

It is a front view showing a hydraulic excavator provided with an offset boom type front device by a 1st embodiment of the present invention. It is a front view which expands and shows an offset boom type front apparatus. It is a principal part enlarged front view which expands and shows a 1st boom, a 2nd boom, a 3rd boom, a link rod, etc. FIG. 4 is a plan view of a first boom, a second boom, a third boom, a link rod and the like shown in FIG. 3. It is an enlarged front view of a partially broken view showing in an enlarged manner a state in which a hydraulic pipe is connected to a link rod. It is a top view which shows the state which connected each hydraulic piping to the link rod in FIG. FIG. 7 is an enlarged cross-sectional view of the passage member and the oil passage as seen from the direction of arrows VII-VII in FIG. 5. It is a front view which shows the principal part of the offset boom type front apparatus by the 2nd Embodiment of this invention. It is top views, such as a 1st boom shown in FIG. 8, a 2nd boom, a 3rd boom, a link rod. It is an enlarged front view of a partially broken view showing in an enlarged manner a state in which a hydraulic pipe is connected to a link rod. It is a top view which shows the state which connected each hydraulic piping to the link rod in FIG. It is an expanded cross-sectional view which looked at the channel | path member, the oil path, and the binding tool from the arrow XII-XII direction in FIG.

Explanation of symbols

2 Lower traveling body (car body)
3 Upper swing body (car body)
DESCRIPTION OF SYMBOLS 11 Offset boom type front apparatus 12 1st boom 13 2nd boom 15 3rd boom 17 Arm 18 Bucket (working tool)
19 Boom cylinder 20 Arm cylinder 21 Bucket cylinder (work implement cylinder)
23 Offset cylinder 24, 41 Link rod 25, 42 Passage member 26, 43 Oil passage 27, 45 First boom side mounting eye (first boom side mounting portion)
28, 46 Third boom side mounting eye (third boom side mounting portion)
29 1st hydraulic piping 30 2nd hydraulic piping 31, 44 Hydraulic line 47 Binding tool

Claims (4)

A first boom that is attached to the vehicle body on the base end side and moves up and down by a boom cylinder; a second boom that is attached to the distal end side of the first boom and swings left and right by an offset cylinder; and a distal end of the second boom A third boom attached to the side so as to be swingable in the left and right directions, an arm attached to the distal end side of the third boom and rotated by an arm cylinder, and a work implement cylinder attached to the distal end side of the arm The third boom is pivoted to the opposite side of the second boom when the second boom is swung with respect to the first boom and is attached between the rotating work tool and the first boom and the third boom. In an offset boom type front device comprising a moving link rod,
The link rod is formed of a rigid material having rigidity in a thrust direction, and uses a passage member in which an oil passage for supplying and discharging pressure oil to and from the arm cylinder and / or the work tool cylinder is provided. An offset boom type front device characterized by that.   The link rod is located on one end side in the length direction and is pin-coupled to the first boom, and is connected to the third boom on the other end side in the length direction. The offset boom type front device according to claim 1, comprising: a third boom side mounting portion that is provided, and the passage member provided between the mounting portions.   3. The link rod according to claim 1 or 2, wherein the link rod is formed using a single passage member extending along the second boom, and a plurality of oil passages are provided in the single passage member. Offset boom type front device.   The offset boom type front according to claim 1 or 2, wherein the link rod is formed by using a plurality of passage members extending along the second boom, and each passage member is provided with the oil passage. apparatus.

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