JP6498620B2 - Hydraulic excavator with crane function - Google Patents

Description

  The present invention relates to a hydraulic excavator having a crane function capable of performing excavation work using a bucket and performing crane work for transporting a suspended load using a hook.

  In general, a hydraulic excavator, which is a typical example of a construction machine, includes a self-propelled vehicle body and a front device provided on the vehicle body. The front device includes a boom attached to the vehicle body so as to be able to move up and down, an arm rotatably attached to the tip end side of the boom, and a bucket attached to the tip end side of the arm and rotated by a bucket cylinder. It is configured.

  Here, a hydraulic excavator (a hydraulic excavator having a crane function) in which a hook is provided on a bucket link that connects a bucket cylinder and a bucket is known. This hydraulic excavator operates a boom and an arm in a state in which a heavy object (suspended load) is suspended using a hook, and swings an upper swing body constituting the vehicle body, thereby performing a crane operation for transporting the suspended load. It can be carried out.

  In a hydraulic excavator having a crane function, a hook storage space is formed in the bucket link, and when excavation work is performed using the bucket, the hook is stored in the hook storage space of the bucket link, and the crane work is performed using the hook. When doing, the hook is taken out of the hook storage space. The bucket link is provided with a hook sensor, and the hook sensor detects whether or not the hook is stored in the hook storage space of the bucket link (see, for example, Patent Document 1).

JP 2003-119832 A

  Here, in the hydraulic excavator according to Patent Document 1, a non-contact type hook sensor including a proximity switch is provided in the hook storage space, and when the hook is stored in the hook storage space, the hook is directly moved by the hook sensor. To detect.

  However, since the hook is cast-molded, the dimensional tolerance is large, and it is difficult to stabilize the detection distance when the hook is detected by the hook sensor. For this reason, it is difficult to ensure the detection accuracy of the hook sensor.

  Further, the above-described hydraulic excavator performs excavation work of earth and sand using a bucket while being stored in the hook storage space. For this reason, earth and sand may enter the hook storage space of the bucket link, and the earth and sand may collide with the detection part of the hook sensor, so that the hook sensor may be damaged.

  The present invention has been made in view of the above-described problems of the prior art, and can accurately detect whether or not the hook is stored in the hook storage space, and can protect the hook sensor from earth and sand. An object of the present invention is to provide a hydraulic excavator having a crane function.

  The present invention comprises a self-propelled vehicle body and a front device provided on the vehicle body, the front device being pivotably mounted on the vehicle body so as to be able to move up and down, and pivotable to a tip end side of the boom. An arm attached to the front end of the arm, a bucket for excavation work attached to the front end side of the arm and rotated by a bucket cylinder, and a hook storage space is formed inside the bucket and the bucket cylinder. A bucket link, a hook for crane operation provided on the bucket link, and whether the hook is in a storage position stored in the hook storage space or an extraction position extracted from the hook storage space When the output of the hook sensor is in the retracted position, the excavation work mode that allows excavation work using the bucket is provided. And when the output of the hook sensor is at the take-out position, a controller for controlling to switch to a crane work mode that allows crane work using the hook is provided. A pair of connecting plates that are connected to each other between the connecting portion of the first connecting portion and the second connecting portion on the bucket side, and a closing plate that closes between one end face of each of the connecting plates; Each of the connecting plates is formed in a box shape having an opening provided between the other end faces, and the hook storage space of the bucket link includes the hook for guiding the hook to the storage position. A pair of guide members provided on the closing plate of the bucket link and sandwiching the hook from both sides, and one of the guide members provided on one guide member, the hook is locked in the retracted position. Hook holding mechanism having a locking member which is applied to a hydraulic excavator having a crane function provided.

The present invention is characterized in that the other guide member among the guide members, the other connection plate facing the other guide member among the connection plates, and the closing plate, A sensor housing chamber that is a space protected against an external obstacle is formed in the sensor housing chamber, and a detection portion of the hook sensor is provided in a state isolated from the hook, and the hook is A configuration is provided in which a detection member that is displaced by the hook when it is stored in the storage position and the displacement is detected by the hook sensor is provided, and the detection unit of the hook sensor faces the detection member Provided on the other guide member, and the hook sensor is provided with a detection distance adjustment mechanism for adjusting a distance when detecting the detection member. Lies in that the configuration and the.

  According to the present invention, a sensor protected against an external obstacle inside the hook storage space by the closing plate and the other connecting plate constituting the bucket link and the other guide member constituting the hook holding mechanism. A storage chamber is formed, and a detection portion of the hook sensor is provided in the sensor storage chamber. Therefore, even if an external obstacle such as earth and sand enters the hook storage space of the bucket link by performing excavation work using the bucket, the detection unit of the hook sensor in which the earth and sand is accommodated in the sensor accommodation chamber Can be suppressed, and the hook sensor can be protected.

  Further, the detection member provided in the sensor storage chamber is displaced when the hook is stored in the storage position, and the hook sensor indirectly detects whether or not the hook is stored in the storage position by the detection member. . Thereby, the detection distance between the hook sensor and the detection member is stabilized, and the detection accuracy of the hook sensor can be ensured with high accuracy.

It is a front view which shows the hydraulic excavator provided with the crane function by embodiment of this invention. It is the bottom view which looked at the bucket link apparatus with a hook in FIG. 1 from the arrow II-II direction. It is sectional drawing which looked at the bucket link apparatus with a hook from the arrow III-III direction in FIG. It is sectional drawing which looked at the bucket link apparatus with a hook from the arrow IV-IV direction in FIG. It is a partially broken perspective view showing a hook, a hook holding mechanism, a hook sensor, a detection plate and the like. It is sectional drawing which looked at the hook hold | maintained in the storing position, a hook holding mechanism, a hook sensor, a detection plate, etc. from the arrow VI-VI direction in FIG. FIG. 7 is a cross-sectional view of the same position as in FIG. 6 showing a hook, a hook holding mechanism, a hook sensor, a detection plate, and the like detached from the storage position. 1 is a system configuration diagram including a hydraulic system that controls a bucket cylinder, a controller, a hook sensor, and the like. FIG. It is a flowchart which shows the control processing which a controller performs.

  Hereinafter, embodiments of a hydraulic excavator having a crane function according to the present invention will be described in detail with reference to the accompanying drawings.

  In FIG. 1, a hydraulic excavator 1 having a crane function has a vehicle body composed of a wheel-type lower traveling body 2 that can be self-propelled and an upper revolving body 3 that is rotatably mounted on the lower traveling body 2. ing. A cab 3A that defines an operator's cab and on which an operator rides is provided on the front left side of the upper swing body 3, and a front device 4 is provided at the center of the front of the upper swing body 3 so as to be able to be lifted and lowered. .

  The front device 4 has a boom 5 attached to the front side of the upper swing body 3 so as to be able to move up and down, an arm 6 attached to the front end side of the boom 5 so as to be rotatable, and a turnable side to the front end side of the arm 6. An attached bucket 7, a boom cylinder 8 that drives the boom 5, an arm cylinder 9 that drives the arm 6, and a bucket cylinder 10 that drives the bucket 7 are configured.

  Here, the bucket 7 is provided with two brackets 7A that are spaced apart in the left and right directions, and the tip of the arm 6 is disposed between each bracket 7A. The bucket 7 is rotatably supported at the tip of the arm 6 around the support shaft 11 inserted through the bracket 7A and the arm 6.

  Two connecting links 12 are provided between the distal end side of the arm 6 and the distal end portion of the rod 10 </ b> A of the bucket cylinder 10 so as to be separated in the left and right directions. One end side of each connecting link 12 is rotatably supported on the tip end side of the arm 6 via a support shaft 13, and the other end side of each connecting link 12 is connected to the rod 10 </ b> A of the bucket cylinder 10 via the connecting shaft 14. It is connected with the front-end | tip part of this so that rotation is possible.

  Next, a bucket link 15 is provided between the bucket 7 and the bucket cylinder 10 to connect the two. The bucket link 15 is configured as a hook-attached bucket link in which a later-described crane work hook 26 is stored.

  One end side in the length direction of the bucket link 15 is connected to the tip of the rod 10 </ b> A of the bucket cylinder 10 together with the connection link 12 via the connection shaft 14 so as to be rotatable. The other end side in the length direction of the bucket link 15 is rotatably connected to each bracket 7A of the bucket 7 by using a connecting shaft 20 described later. Here, the bucket link 15 includes left and right cylinder side bosses 16 and 17, left and right bucket side bosses 18 and 19, left and right connecting plates 21 and 22, a closing plate 23, It is in the form of a box having an opening 24 and is integrally formed using means such as casting.

  The left cylinder side boss 16 and the right cylinder side boss 17 as the first connecting portion are formed in a cylindrical shape extending in the left and right directions, respectively, and are arranged to face each other with a space in the left and right directions. A cylindrical bush 16A is inserted into the inner peripheral side of the left cylinder-side boss 16, and a cylindrical bush 17A is inserted into the inner peripheral side of the right cylinder-side boss 17, and these bushes 16A, 17A are inserted. The connecting shaft 14 is inserted through the inside. Between the left and right cylinder side bosses 16 and 17, the tip of the rod 10 </ b> A of the bucket cylinder 10 is disposed, and the cylinder side bosses 16 and 17 are sandwiched between the left and right connecting links 12. The cylinder side bosses 16 and 17, the rod 10 </ b> A of the bucket cylinder 10, and the connection links 12 are rotatably connected by a connection shaft 14.

  The left bucket-side boss 18 and the right bucket-side boss 19 as the second connecting portion are formed in a cylindrical shape extending in the left and right directions, respectively, and are arranged to face each other with an interval in the left and right directions. A cylindrical bush 18A is inserted into the inner peripheral side of the left bucket-side boss 18, and a cylindrical bush 19A is inserted into the inner peripheral side of the right bucket-side boss 19, and each of these bushes 18A, 19A is inserted. The connecting shaft 20 is inserted through the inside. A hook boss 27 described later is disposed between the left and right bucket-side bosses 18 and 19, and the bucket-side bosses 18 and 19 are sandwiched between the left and right brackets 7A provided on the bucket 7. The bucket bosses 18 and 19, the hook boss 27, and the brackets 7 A of the bucket 7 are rotatably connected by a connecting shaft 20.

  The left connecting plate 21 connects the left cylinder side boss 16 and the left bucket side boss 18, and the right connecting plate 22 connects the right cylinder side boss 17 and the right bucket side boss 19. The left connecting plate 21 and the right connecting plate 22 are paired in the left and right directions. Here, the left connecting plate 21 and the right connecting plate 22 have the same width as the outer diameters of the cylinder side bosses 16 and 17 and the bucket side bosses 18 and 19, and are spaced apart in the left and right directions. Face to face.

  The closing plate 23 closes the gap between one end face in the width direction of the left and right connecting plates 21 and 22. The closing plate 23 is formed in a rectangular flat plate shape, and extends in the left and right directions between an end surface on one side in the width direction of the left connecting plate 21 and an end surface on one side in the width direction of the right connecting plate 22. The left connecting plate 21 and the right connecting plate 22 are closed in a connected state. The closing plate 23 is provided with a hook holding mechanism 31 to be described later.

  The opening 24 is provided between the end surfaces 21A and 22A on the other side in the width direction which is opposite to the closing plate 23 in the width direction of the left and right connecting plates 21 and 22. As shown in FIG. 2, the opening 24 is formed as a quadrangular opening disposed at the center in the left, right, and length directions of the bucket link 15, and a hook 26 described later is inserted therethrough.

  The hook storage space 25 is a space surrounded by left and right cylinder-side bosses 16 and 17, left and right bucket-side bosses 18 and 19, left and right connecting plates 21 and 22, etc. that constitute the bucket link 15. Is formed. The hook storage space 25 is provided to store the hook 26 in the bucket link 15 and communicates with the outside of the bucket link 15 through the opening 24.

  The hook 26 for crane work is stored in the hook storage space 25. The hook 26 is swingably supported by the left and right bucket-side bosses 18 and 19 using the connecting shaft 20. As shown by a two-dot chain line in FIG. 1, the hook 26 is taken out of the bucket link 15 to suspend and carry a suspended load (neither shown) via a rope or the like. Used for. On the other hand, when the excavator 1 performs excavation work using the bucket 7, the hook 26 is stored in the hook storage space 25 of the bucket link 15 as shown in FIG. Here, the hook 26 includes a hook boss 27, a joint member 28, a flange member 30 and the like which will be described later.

  The hook boss 27 is provided between the bucket side bosses 18 and 19 of the bucket link 15 so as to be rotatable about the connecting shaft 20. A bush 27A is inserted into the inner peripheral side of the hook boss 27, and the connecting shaft 20 is inserted into the bush 27A (see FIG. 2). A pair of brackets 27B is provided on the outer peripheral side of the hook boss 27, and the brackets 27B face each other at a constant interval.

  The joint member 28 is rotatably attached to each bracket 27 </ b> B of the hook boss 27 via a shaft 29. The joint member 28 is formed integrally with the cylindrical portion 28A that rotatably supports the flange member 30 via a bearing or the like (not shown), and the bracket portion 27B of the hook boss 27. And the attached mounting portion 28B. The attachment portion 28B of the joint member 28 is attached to each bracket 27B of the hook boss 27 so as to be rotatable (swingable) about the shaft 29.

  The flange member 30 is rotatably supported by the cylindrical portion 28A of the joint member 28 via a bearing (not shown). The eaves member 30 is formed in a substantially J shape, and hooks a rope for hanging load or the like during crane operation. For this reason, the rope member 30 is provided with a rope retaining member 30A, and the rope retaining member 30A prevents the rope hooked on the collar member 30 from being pulled out.

  Therefore, the hook 26 rotates about the connecting shaft 20 and moves in the direction of arrow A in FIG. The hook 26 is configured to be held by a hook holding mechanism 31 (to be described later) while being stored in the hook storage space 25.

  The hook holding mechanism 31 is provided in the hook storage space 25 of the bucket link 15. The hook holding mechanism 31 holds the hook 26 in the hook storage space 25 when the excavator 1 does not perform crane work. Here, the hook holding mechanism 31 includes a substrate 32 (described later), one guide member 33, the other guide member 36, and a lock member 39.

  The substrate 32 is located in the hook storage space 25 of the bucket link 15 and is provided on the closing plate 23. The substrate 32 is formed in a rectangular flat plate shape having a smaller area than the opening 24 of the bucket link 15 and is detachably attached to the closing plate 23 using a plurality of bolts 32A. One guide member 33 as a pair of guide members and the other guide member 36 are provided on the surface 32B side of the substrate 32 opposite to the closing plate 23.

  One guide member 33 is provided on the right connecting plate 22 side located on one side of the bucket link 15 in the left and right directions. One guide member 33 guides the hook 26 stored in the bucket link 15 to the hook storage space 25 by sandwiching the hook member 30 of the hook 26 from the left and right sides with the other guide member 36. Is.

  Here, as shown in FIG. 6 and the like, the one guide member 33 is formed in a substantially rectangular flat plate shape using a steel plate material or the like, and is constant in the length direction of the connection plates 21 and 22 of the bucket link 15. Two guide plates 33A facing each other with a gap are provided. Each one guide plate 33 </ b> A is fixed to the surface 32 </ b> B of the substrate 32 using means such as welding, and the protruding end of each one guide plate 33 </ b> A protruding from the substrate 32 extends toward the opening 24. . Each one guide plate 33 </ b> A is connected by a connecting plate 33 </ b> B, and the attachment strength to the substrate 32 is increased. Both ends of a lock member support shaft 34 described later are attached to the protruding end side of each one guide plate 33A, and both ends of a stopper pin 35 described later are attached.

  The lock member support shaft 34 is provided on the protruding end side of each one guide plate 33 </ b> A, and extends in the length direction of each connection plate 21, 22 of the bucket link 15. Both end portions of the lock member support shaft 34 are rotatably inserted into the respective one guide plates 33A and are prevented from being removed in the axial direction. The lock member support shaft 34 rotatably supports a lock member 39 to be described later between each one of the guide plates 33A, and a lock member biasing spring 40 to be described later is attached thereto.

  The stopper pin 35 is located in the vicinity of the lock member support shaft 34 and is provided on the protruding end side of each one guide plate 33 </ b> A, and extends in the length direction of each coupling plate 21, 22 of the bucket link 15. . Both end portions of the stopper pin 35 are fixedly inserted into the protruding end side of each one guide plate 33A. The stopper pin 35 is configured to restrict a movable range of the lock member 39 and to be engaged with one end 40A of the lock member biasing spring 40 by contacting a lock member 39 that rotates about the lock member support shaft 34. It is.

  The other guide member 36 is provided on the left connecting plate 21 side located on the other side in the left and right directions of the bucket link 15, and faces the one guide member 33 in the left and right directions. As shown in FIG. 6 and the like, the other guide member 36 faces a rising plate 36A having an inverted L-shaped cross section rising from the closing plate 23 of the bucket link 15 toward the opening 24, and the rising plate 36A. It includes two rectangular side plates 36B and 36C and a long groove hole 36D as a detection plate passage hole provided in the rising plate 36A.

  Here, the rising plate 36A extends from the closing plate 23 of the bucket link 15 toward the opening 24 and extends from the protruding end of the vertical plate portion 36A1 toward the left connecting plate 21 of the bucket link 15. And a horizontal plate portion 36A2. The side plates 36B and 36C are provided at both ends of the rising plate 36A in the length direction of the connecting plates 21 and 22 of the bucket link 15, and face each other with a certain distance in the length direction of the connecting plates 21 and 22. ing. The long groove hole 36D is located between the two side plates 36B and 36C, is formed in the vertical plate portion 36A1 of the rising plate 36A, and extends from the closing plate 23 of the bucket link 15 toward the opening 24. A detection plate 42, which will be described later, is rotatably provided between the side plates 36B and 36C, and the detection plate 42 passes through the long groove hole 36D.

  Here, as shown in FIG. 6, a guide space 37 extending in the moving direction of the hook 26 (in the direction of arrow A) is formed between the one guide member 33 and the other guide member 36, and this guide space. By inserting the hook member 30 of the hook 26 into the member 37, one guide member 33 and the other guide member 36 are configured to guide the hook member 30 from both left and right sides.

  On the other hand, in the hook storage space 25 of the bucket link 15, a sensor housing chamber 38 is formed that is partitioned by the other guide member 36, the left connecting plate 21 that constitutes the bucket link 15, and the closing plate 23. . More specifically, the sensor housing chamber 38 is formed as a space surrounded by a rising plate 36A and two side plates 36B and 36C constituting the other guide member 36, and a detection portion 45B of a hook sensor 45 described later. The detection plate 42 and the like are arranged.

  The lock member 39 is rotatably supported between the one guide plates 33 </ b> A via the lock member support shaft 34. As shown in FIGS. 6 and 7, the lock member 39 includes a hook engaging portion 39 </ b> A that engages with the hook member 30 of the hook 26 when the hook 26 is stored in the hook storage space 25, and the hook 26 is hooked. When stored in the storage space 25, the pressed portion 39B pressed by the hook member 30 of the hook 26, the stopper portion 39C contacting the stopper pin 35, and the hook engaging portion 39A from the hook member 30 of the hook 26 are moved. And an operation unit 39D operated by an operator to be detached.

  The lock member 39 rotates about the lock member support shaft 34 in the direction (left and right direction) perpendicular to the moving direction of the hook 26 (the direction of arrow A in FIG. 6), and is indicated by a solid line in FIG. It is rotationally displaced between the hook holding position and the hook releasing position indicated by the two-dot chain line. The lock member 39 holds the hook 26 in the hook storage space 25 by fixing the hook 26 between the guide members 33 and 36 by engaging the hook engaging portion 39A with the flange member 30 in the hook holding position. . On the other hand, the lock member 39 is displaced to the hook release position by the operation of rotating the operation portion 39D in the direction indicated by the arrow B, and the hook engagement portion 39A is detached from the hook member 30, whereby the hook 26 is moved to the hook storage space 25. Is allowed to be taken out of.

  The lock member urging springs 40 are provided on both sides in the axial direction of the lock member support shaft 34 with the lock member 39 interposed therebetween. Each lock member urging spring 40 is formed by, for example, a torsion coil spring, one end 40A of the lock member urging spring 40 is hooked on the stopper pin 35, and the other end 40B of the lock member urging spring 40 is a lock member. 39, the pressed portion 39B is hooked to the peripheral portion on the opposite side in the left and right directions. Thereby, the lock member urging spring 40 constantly urges the lock member 39 toward the hook holding position, and the lock member 39 is stabilized at the position where the stopper portion 39 </ b> C contacts the stopper pin 35.

  A detection plate support shaft 41 is rotatably provided between the two side plates 36B, 36C constituting the other guide member 36. The detection plate support shaft 41 extends in the length direction of the connection plates 21 and 22 constituting the bucket link 15, and both ends of the detection plate support shaft 41 in the axial direction are rotatably inserted into the side plates 36B and 36C. Has been. A detection plate 42 described later is fixed to an intermediate portion in the axial direction of the detection plate support shaft 41.

  The detection plate 42 as a detection member is provided in a sensor housing chamber 38 formed between the side plates 36B and 36C of the other guide member 36 in a state of being attached to the detection plate support shaft 41. The detection plate 42 is formed in a flat plate shape having a plate thickness smaller than the groove width of the long groove hole 36D, and faces the side plates 36B and 36C. Of the detection plate 42, the opening 24 side (upper side in FIG. 6) serves as a mounting portion 42 </ b> A, and this mounting portion 42 </ b> A is fixed to an intermediate portion in the axial direction of the detection plate support shaft 41. Therefore, the detection plate 42 rotates left and right around the detection plate support shaft 41. On the other hand, the closing plate 23 side (the lower side in FIG. 6) of the detection plate 42 is a rotating portion 42B, and this rotating portion 42B has a long groove hole 36D formed in the rising plate 36A of the other guide member 36. By passing, the position is detected between a detection position detected by a hook sensor 45 described later as shown in FIG. 6 and a non-detection position outside the detection range of the hook sensor 45 as shown in FIG.

  Here, the peripheral edge part located on the guide space 37 side of the detection plate 42 becomes a pressed part 42 </ b> C pressed by the hook member 30 of the hook 26 when the hook 26 is stored in the hook storage space 25. Yes. When the hook 26 is stored in the hook storage space 25, the detection plate 42 holds the detection position (position in FIG. 6) by pressing the pressed portion 42 </ b> C by the hook 26. When 26 is taken out, a non-detection position (position in FIG. 7) is held by a detection plate biasing spring 44 described later.

  A stopper pin 43 is provided on the rotating portion 42 </ b> B of the detection plate 42 in the vicinity of the detection plate support shaft 41. The stopper pin 43 has a length dimension larger than the groove width of the long groove hole 36 </ b> D, and extends in parallel with the axial direction of the detection plate support shaft 41. The stopper pin 43 contacts the rising plate 36A when the rotating portion 42B of the detection plate 42 is displaced toward the non-detection position through the long slot 36D, and holds the detection plate 42 at the non-detection position (FIG. 7).

  The detection plate urging springs 44 are provided on both sides of the detection plate support shaft 41 in the axial direction with the detection plate 42 interposed therebetween. Each detection plate urging spring 44 is formed by, for example, a torsion coil spring. One end 44A of the detection plate urging spring 44 is hooked on the horizontal plate portion 36A2 of the rising plate 36A, and the other end 44B of the detection plate urging spring 44 is Of the detection plate 42, the pressed portion 42C is hooked to the peripheral portion on the opposite side in the left and right directions. Thereby, the detection plate urging spring 44 constantly urges the detection plate 42 toward the non-detection position, and the detection plate 42 is stabilized at the non-detection position where the stopper pin 43 contacts the rising plate 36A.

  The hook sensor 45 is located in the vicinity of the closing plate 23 and is attached to the side plate 36 </ b> B of the other guide member 36. The hook sensor 45 is constituted by a proximity switch having a male screw portion 45A and a detection portion 45B. The male screw portion 45A is fixed to the side plate 36B using two nuts 45C while being inserted into the side plate 36B. The detection portion 45B of the hook sensor 45 is disposed in a sensor housing chamber 38 formed between the side plates 36B and 36C of the other guide member 36 in a state of being isolated from the hook 26. Here, the male screw portion 45A and each nut 45C of the hook sensor 45 constitute a detection distance adjustment mechanism that adjusts the distance when the hook sensor 45 detects the detection plate 42. That is, by adjusting the screwing amount of each nut 45C into the male thread portion 45A of the hook sensor 45, the dimension of the detection portion 45B protruding from the side plate 36B into the sensor housing chamber 38 changes. Thereby, the detection unit 45B of the hook sensor 45 can appropriately adjust the distance when detecting the detection plate 42.

  As shown in FIG. 6, when the hook 26 is stored in the hook storage space 25 and the detection plate 42 is displaced to the detection position, the detection unit 45B of the hook sensor 45 approaches (turns to the rotation unit 42B of the detection plate 42). ), The detection plate 42 is detected. For this reason, the detection distance between the hook sensor 45 and the detection plate 42 is stabilized, and the detection accuracy of the hook sensor 45 can be ensured with high accuracy. On the other hand, as shown in FIG. 7, when the hook 26 is taken out from the hook storage space 25 and the detection plate 42 is displaced to the non-detection position, the rotating portion 42 </ b> B of the detection plate 42 is separated from the detection portion 45 </ b> B of the hook sensor 45. By doing so, the detection plate 42 is not detected. In this manner, the hook sensor 45 detects the detection plate 42 that has been displaced to the detection position by the detection unit 45B housed in the sensor housing chamber 38, so that the hook 26 is brought into the storage space 25 by the detection plate 42. The stored signal is indirectly detected, and a detection signal corresponding to whether or not the hook 26 is stored in the hook storage space 25 is output to the controller 57 described later.

  In this case, the detection part 45B of the hook sensor 45 is surrounded by the other guide member 36, the left connecting plate 21 of the bucket link 15, and the closing plate 23, and is protected against external obstacles such as earth and sand. It is arranged in the sensor storage chamber 38. As a result, even if the excavator 1 performs excavation work such as earth and sand using the bucket 7 with the hook 26 held in the hook storage space 25 of the bucket link 15, earth and sand (external obstacle) Is prevented from colliding with the detection unit 45B of the hook sensor 45, and the detection unit 45B can be protected.

  The sensor cover 46 is provided on the surface of the side plate 36 </ b> B constituting the other guide member 36 on the side opposite to the sensor housing chamber 38. As shown in FIG. 5 and the like, the sensor cover 46 is formed of a plate body bent in an inverted L shape, and is fixed to the side plate 36B by means such as welding. The sensor cover 46 covers a portion (attachment portion 45A) of the hook sensor 45 attached to the side plate 36B that protrudes from the sensor accommodation chamber 38, so that earth or sand or the like can be removed from the hook sensor 45 during excavation work using the bucket 7. The hook sensor 45 is protected by suppressing the collision with the mounting portion 45A.

  Next, a hydraulic system for controlling the bucket cylinder 10 will be described with reference to FIG.

  The bucket cylinder 10 is connected to a hydraulic pressure source including a hydraulic pump 47 and a tank 48 via main pipelines 49 and 50. In the middle of the main pipelines 49 and 50, for example, a hydraulic pilot type directional control valve 51 of 6 port 3 position is provided. The directional control valve 51 has hydraulic pilot portions 51A and 51B. When pilot pressure is not supplied to the hydraulic pilot portions 51A and 51B, the directional control valve 51 holds the neutral position (a) and discharges from the hydraulic pump 47. The pressurized oil is discharged to the tank 48. When the pilot pressure is supplied to the hydraulic pilot portion 51A, the direction control valve 51 is switched to the switching position (b) to supply the pressure oil from the hydraulic pump 47 to the rod side oil chamber 10B of the bucket cylinder 10 and the bucket. By discharging the pressure oil in the bottom side oil chamber 10 </ b> C of the cylinder 10 to the tank 48, the bucket cylinder 10 is reduced. When the pilot pressure is supplied to the hydraulic pilot unit 51B, the direction control valve 51 is switched to the switching position (c), and the pressure oil from the hydraulic pump 47 is supplied to the bottom side oil chamber 10C of the bucket cylinder 10 and the bucket. By discharging the pressure oil in the rod side oil chamber 10 </ b> B of the cylinder 10 to the tank 48, the bucket cylinder 10 is extended.

  The pilot operation valve 52 is disposed in the cab 3A of the excavator 1 and is operated by an operator. The pilot operation valve 52 and the hydraulic pilot portion 51A of the direction control valve 51 are connected via a pilot line 53, and the pilot operation valve 52 and the hydraulic pilot portion 51B of the direction control valve 51 are connected to a pilot pipe. They are connected via a path 54. In the middle of these pilot pipelines 53, 54, solenoid valves 55, 56 at 3 ports and 2 positions are provided, respectively.

  When the signal from the controller 57 (described later) is not output to the electromagnetic pilot section 55A, the solenoid valve 55 holds the communication position (d) for communicating the pilot conduit 53, and when the signal from the controller 57 is output. Then, the pilot line 53 is switched to the cutoff position (e). On the other hand, when the signal from the controller 57 is not output to the electromagnetic pilot unit 56A, the solenoid valve 56 holds the communication position (f) for communicating the pilot conduit 54, and when the signal from the controller 57 is output. Then, the pilot line 54 is switched to the cutoff position (g). Therefore, when a signal is output from the controller 57 to the electromagnetic pilot portions 55A and 56A of the electromagnetic valves 55 and 56, the electromagnetic valves 55 and 56 are switched to the cutoff positions (e) and (g), thereby the pilot operation valve 52. Even if is operated, the bucket cylinder 10 is kept in a non-operating state.

  Next, a controller 57 that switches the working mode of the hydraulic excavator 1 based on a detection signal from the hook sensor 45 will be described with reference to FIG.

  The controller 57 is mounted on the hydraulic excavator 1 and, based on a detection signal from the hook sensor 45 and a signal from a manual selection switch 59 and the like, which will be described later, the hydraulic excavator 1 is craned using the hook 26 (hanging work). The operation mode is switched between the crane operation mode when performing the excavation and the excavation operation mode using the bucket 7.

  A hook sensor 45, a key switch 58, a manual selection switch 59, and the like are connected to the input side of the controller 57. The key switch 58 is disposed in the cab 3A and is operated by the operator when starting the engine 60 of the excavator 1. The manual selection switch 59 is disposed in the cab 3A and is operated by the operator to arbitrarily select the crane work mode and the excavation work mode regardless of the detection signal from the hook sensor 45, for example.

  Connected to the output side of the controller 57 are an engine 60, a monitor screen 61, electromagnetic pilot portions 55A, 56A of electromagnetic valves 55, 56, and the like. The controller 57 performs control to switch the excavator 1 between the crane work mode and the excavation work mode based on signals input from the hook sensor 45, the key switch 58, the manual selection switch 59, and the like.

  In the present embodiment, when the hook 26 is in the take-out position taken out of the storage space 25 (position in FIG. 7), the hook sensor 45 outputs an ON signal to the controller 57, and the hook 26 is stored in the storage space 25. The hook sensor 45 outputs an OFF signal to the controller 57 when in the retracted storage position (position shown in FIG. 6). In addition, when the hook sensor 45 malfunctions due to a failure of the hook sensor 45 or a disconnection of a harness connected to the hook sensor 45, the hook sensor 45 outputs an OFF signal to the controller 57. In this case, when the hook sensor 45 malfunctions with the hook 26 in the removal position, the hook sensor 45 outputs an OFF signal to the controller 57. The controller 57 performs crane work by the control process shown in FIG. The mode is maintained. Further, when the hook 26 is in the take-out position (during crane work), even if the manual selection switch 59 is mistakenly switched to the excavation work mode side, the controller 57 sets the crane work mode by the control process of FIG. It is the structure to hold.

  When the controller 57 executes the crane work mode, the controller 57 limits (decreases) the rotational speed of the engine 60 in order to prevent the suspended load suspended by the hook 26 from swinging, for example, when the upper swing body 3 is turned. ) In addition, the controller 57 prohibits the expansion and contraction of the bucket cylinder 10 regardless of the operation of the pilot operation valve 52 by outputting a signal to the electromagnetic pilot portions 55A and 56A of the electromagnetic valves 55 and 56. Furthermore, the controller 57 is input from an angle sensor that individually detects the rotation angles of the boom 5 and the arm 6 and a load sensor that detects the weight of the suspended load that is suspended from the hook 26 (both not shown). Based on the detection signal or the like, for example, the rated load of the suspended load or the stability of the vehicle body corresponding to the posture of the front device 4 is calculated, and the calculation result is displayed on the monitor screen 61.

  On the other hand, when the controller 57 executes the excavation work mode, the controller 57 stops outputting signals to the electromagnetic pilot portions 55A and 56A of the electromagnetic valves 55 and 56, and the bucket cylinder 10 corresponding to the operation of the pilot operation valve 52 is activated. Allow telescopic movement. In addition, the controller 57 releases the restriction on the rotational speed of the engine 60, and displays on the monitor screen 61 a display different from that during crane work, for example, a fuel gauge, an engine coolant temperature gauge, and the like.

  The hydraulic excavator 1 according to the present embodiment has the above-described configuration, and an operation for removing the hook 26 from the bucket link 15 in order to perform a crane operation will be described.

  In this case, the hook 26 is in the retracted position shown in FIGS. 3 to 6, and the hook member 30 of the hook 26 has one guide member 33 constituting the hook holding mechanism 31 and the other guide, as shown in FIG. It is arranged between the member 36. A hook engaging portion 39A of the lock member 39 held at the hook holding position is engaged with the inner peripheral side of the flange member 30. On the other hand, the detection plate 42 holds the detection position against the detection plate urging spring 44 by pressing the pressed portion 42 </ b> C against the hook member 30 of the hook 26. Therefore, the hook sensor 45 detects that the hook 26 is in the retracted position by the detection plate 42 and outputs an OFF signal to the controller 57. At this time, by adjusting the screwing amount of each nut 45C into the male screw portion 45A of the hook sensor 45, the distance when the detection portion 45B of the hook sensor 45 detects the detection plate 42 can be adjusted appropriately. .

  In this state, the operation portion 39D of the lock member 39 is operated in the direction indicated by the arrow B, and the lock member 39 is rotationally displaced to the hook release position indicated by the two-dot chain line in FIG. As a result, the hook engaging portion 39A of the lock member 39 is detached from the flange member 30 of the hook 26, so that the hook 26 is placed between one guide member 33 and the other guide member 36 as shown in FIG. Can be extracted in the direction of arrow A. As a result, the hook 26 moves away from the hook storage space 25 of the bucket link 15 around the connecting shaft 20 and moves to a position indicated by a two-dot chain line in FIG.

  At this time, when the engagement of the detection plate 42 with the hook 26 is released, the detection plate biasing spring 44 rotates the detection plate 42 from the detection position of FIG. 6 to the non-detection position of FIG. The non-detection position is held by contacting the rising plate 36A of the guide member 36. Accordingly, the hook sensor 45 detects that the hook 26 has been displaced to the removal position by the detection plate 42 and outputs an ON signal to the controller 57.

  In this manner, for example, the boom 5 and the arm are swung while the upper revolving unit 3 is swung by suspending a suspended load (both not shown) from the hook 26 taken out from the bucket link 15 using a rope or the like. The crane operation which conveys a suspended load to a desired place can be performed by raising and lowering 6.

  Next, when the hook 26 is stored in the hook storage space 25 of the bucket link 15 in order to perform excavation work using the bucket 7, the hook 26 is gripped and directed toward the hook storage space 25 around the connecting shaft 20. To rotate. Then, as shown in FIG. 7, the hook member 30 of the hook 26 is inserted into the guide space 37 formed between the guide members 33 and 36 constituting the hook holding mechanism 31.

  At this time, the lock member 39 holds the hook holding position by the lock member biasing spring 40, and the detection plate 42 holds the non-detection position by the detection plate biasing spring 44. In contrast, when the hook member 30 of the hook 26 presses the pressed portion 39B of the lock member 39, the lock member 39 once rotates to the hook release position against the lock member biasing spring 40. . When the outer periphery of the flange member 30 gets over the hook engaging portion 39A of the lock member 39, the lock member 39 is automatically returned to the hook holding position by the lock member biasing spring 40.

  On the other hand, when the hook member 30 of the hook 26 presses the pressed portion 42C of the detection plate 42, the detection plate 42 rotates to the detection position against the detection plate urging spring 44, and this detection position is changed. Hold. Accordingly, the hook sensor 45 detects that the hook 26 is in the storage position by the detection plate 42 and outputs an OFF signal to the controller 57.

  Thus, excavation of earth and sand etc. is performed by rotating the bucket 7 by the bucket cylinder 10 while the boom 5 and the arm 6 are moved up and down while the hook 26 is stored in the hook storage space 25 of the bucket link 15. Work can be done.

  In this case, in the present embodiment, the other guide member 36 constituting the hook holding mechanism 31, the left connecting plate 21 facing the other guide member 36 among the connecting plates 21 and 22 of the bucket link 15, and the bucket A sensor housing chamber 38 that divides the inside of the hook storage space 25 is formed by the closing plate 23 of the link 15, and a detection portion 45 </ b> B of the hook sensor 45 is provided in the sensor housing chamber 38 while being isolated from the hook 26. At the same time, when the hook 26 is stored at the storage position, it is displaced to the detection position by being pressed by the hook 26, and a detection plate 42 is provided for detecting the state displaced to this detection position by the hook sensor 45.

  Thereby, even if earth and sand etc. enter the hook storage space 25 of the bucket link 15 by performing excavation work using the bucket 7 with the hook 26 stored in the hook storage space 25 of the bucket link 15, It is possible to prevent the earth and sand from colliding with the detection portion 45B of the hook sensor 45 accommodated in the sensor accommodating chamber 38. As a result, the hook sensor 45 can be prevented from being damaged and the hook sensor 45 can be protected, so that the time and cost required for replacing the hook sensor 45 can be reduced.

  Moreover, the hook sensor 45 detects whether or not the hook 26 is stored in the storage position by detecting that the detection plate 42 disposed in the sensor storage chamber 38 is displaced between the detection position and the non-detection position. Can be detected indirectly. As a result, since the detection distance between the hook sensor 45 and the detection plate 42 is stabilized, the detection accuracy of the hook sensor 45 can be ensured with high accuracy. Furthermore, since it is not necessary to separately provide a cover that covers the detection portion 45B of the hook sensor 45, the hook holding mechanism 31 can be formed in a compact manner.

  In the present embodiment, the other guide member 36 includes a rising plate 36A that rises from the closing plate 23 of the bucket link 15 toward the opening 24, and each side plate 36B that is provided on a side end surface of the rising plate 36A. 36C, a detection plate support shaft 41 that is provided on each of the side plates 36B and 36C and rotatably supports the detection plate 42, and a detection plate 42 that is provided on the rising plate 36A rotates about the detection plate support shaft 41. The detection plate 42 is configured to include a long slot 36D through which the detection plate 42 passes, and the detection plate 42 is detected by the hook sensor 45 in the sensor housing chamber 38 when pressed by the hook 26 stored in the storage position. And a non-detection position that protrudes out of the sensor housing chamber 38 through the long slot 36D and deviates from the detection range by the hook sensor 45 when the hook 26 is detached from the storage position. In is configured to be displaced.

  As a result, when the hook 26 is stored in the storage position, the detection plate 42 is pressed by the hook 26 and rotationally displaced to the detection position about the detection plate support shaft 41, so that the detection plate 42 displaced to the detection position is hooked. By being detected by the sensor 45, it is possible to indirectly detect that the hook 26 has been stored in the storage position. On the other hand, when the detection plate 42 is displaced to the non-detection position and deviates from the detection range by the hook sensor 45, it is possible to indirectly detect that the hook 26 is detached from the storage position.

  In addition, since the hook sensor 45 is provided on the other guide member 36 constituting the hook holding mechanism 31, the hook holding mechanism 31 and the hook sensor 45 can be formed as one unit. As a result, the unitized hook holding mechanism 31 and the hook sensor 45 can be easily attached to another bucket link having a different size from the bucket link 15.

  Further, in the present embodiment, a sensor cover 46 is provided on the side plate 36B of the other guide member 36 so as to cover a portion of the hook sensor 45 that protrudes from the sensor housing chamber 38 (attachment portion 45A). Accordingly, the attachment portion 45 </ b> A of the hook sensor 45 protruding from the sensor storage chamber 38 can be protected from earth and sand by the sensor cover 46.

  Next, in the present embodiment, the controller 57 is connected to the crane 57 based on the detection signal output from the hook sensor 45, the signal output from the manual selection switch 59, etc., depending on whether or not the hook 26 is in the retracted position. The operation mode and the excavation operation mode are switched, and the control process executed by the controller 57 will be described below with reference to FIG.

  First, the case where the hook 26 is at the take-out position and the crane operation mode is selected by the manual selection switch 59 will be described. When the control process by the controller 57 is started, it is determined in step 1 whether or not the key switch 58 arranged in the cab 3A has been turned ON to start the engine 60. This determination is repeated while “NO” is determined in Step 1, and when “YES” is determined in Step 1, the process proceeds to Step 2. In step 2, the control flag is set to “0” as an initial setting, and the process proceeds to step 3.

  In step 3, it is determined whether or not the detection signal output from the hook sensor 45 is an ON signal and the control flag is “0”. In this case, the hook sensor 45 outputs an ON signal when the hook 26 is at the take-out position (position in FIG. 7) taken out from the storage space 25. In step 2, the control flag is set to “0”. Accordingly, when the hook 26 is in the take-out position, the process proceeds to step 4 where the control flag is set to “1” and the process proceeds to step 5.

  In step 5, control according to the crane work mode is performed. For example, the controller 57 outputs a signal to the electromagnetic pilot portions 55A and 56A of the electromagnetic valves 55 and 56, and switches the electromagnetic valves 55 and 56 to the cutoff positions (e) and (g). Thereby, even if the pilot operation valve 52 is operated, the bucket cylinder 10 does not operate, and the bucket 7 is fixed to the posture shown in FIG. 1, for example. Further, the controller 57 limits the rotation speed of the engine 60 in order to prevent the suspended load suspended by the hook 26 from swinging when the upper swing body 3 is swung.

  Furthermore, the controller 57 is input from an angle sensor that individually detects the rotation angles of the boom 5 and the arm 6 and a load sensor that detects the weight of the suspended load that is suspended from the hook 26 (both not shown). Based on the detection signal or the like, for example, the rated load of the suspended load or the stability of the vehicle body corresponding to the posture of the front device 4 is calculated, and the calculation result is displayed on the monitor screen 61. Therefore, the operator can monitor the work state of the crane work by visually observing the monitor screen 61, and can perform the crane work safely.

  After executing Step 5, the process proceeds to Step 6 to determine whether or not the key switch 58 has been turned OFF. If “YES” is determined in the step 6, the key switch 58 is turned off and the engine 60 is stopped, so the control process is ended. On the other hand, if “NO” is determined in Step 6, the process proceeds to Step 3. In this case, since the control flag is set to “1” in step 4, “NO” is determined in step 3, and the process proceeds to step 7.

  In step 7, it is determined whether or not the manual selection switch 59 disposed in the cab 3A has selected the crane work mode. If “YES” in the step 7, that is, if it is determined that the crane work mode is selected by the manual selection switch 59, the process proceeds to a step 5 to hold the crane work mode. In this way, when the hook 26 is at the take-out position and the crane work mode is selected by the manual selection switch 59, the crane work mode can be maintained by repeating the above steps 5, 6, 3, and 7. it can.

  Next, a case where the excavation work mode is selected by the manual selection switch 59 when the hook 26 is in the retracted position or the hook sensor 45 is malfunctioning will be described. In this case, after proceeding to steps 1, 2, and 3, “NO” is determined at step 3, and the routine proceeds to step 7.

  In this case, since the excavation work mode is selected by the manual selection switch 59 arranged in the cab 3A, it is determined as “NO” in Step 7, the control flag is set to “0”, and then the process proceeds to Step 9. .

  In step 9, control according to the excavation work mode is performed. For example, the controller 57 stops outputting signals to the electromagnetic pilot portions 55A and 56A of the electromagnetic valves 55 and 56, and switches the electromagnetic valves 55 and 56 to the communication positions (d) and (f). Thereby, the bucket cylinder 10 expands and contracts according to the operation of the pilot operation valve 52, and the sand can be excavated using the bucket 7. In addition, the controller 57 releases the restriction on the rotational speed of the engine 60 and displays on the monitor screen 61 display contents different from those during crane work, such as a fuel gauge and an engine cooling water temperature gauge.

  After step 9 is executed, the process proceeds to step 6, and when “NO” is determined in step 6, the process proceeds to step 3. In this case, since an OFF signal is output from the hook sensor 45, it is determined as “NO” in Step 3, and the process proceeds to Step 7. Therefore, when the excavation work mode is selected by the manual selection switch 59, the excavation work mode can be maintained by repeating the above-described steps 9, 6, 3, 7, and 8.

  Here, when the hook sensor 45 malfunctions during execution of the crane work mode, an OFF signal is output from the hook sensor 45. In this case, “NO” is determined in step 3 and the process proceeds to step 7. Therefore, as long as the crane operation mode is selected by the manual selection switch 59, the above steps 5, 6, 3 and 7 are repeated. Therefore, even when the hook sensor 45 is out of order during the crane work, the crane work can be continued by maintaining the crane work mode.

  Next, when the manual selection switch 59 is erroneously switched to the excavation work mode while the crane work mode is being executed, the controller 57 determines “NO” in step 7, and steps 8 and 9. , 6 to step 3. In this case, since the control flag is set to “0” in Step 8, “YES” is determined in Step 3, and the process proceeds to Step 3 via Steps 4, 5, and 6. In this case, since the control flag is set to “1” in step 4, it is determined as “NO” in step 3, and the process proceeds to step 3 again via steps 7, 8, 9, and 6.

  As described above, when the manual selection switch 59 is mistakenly switched to the excavation work mode when the crane work mode is being executed, the controller 57 performs the above-described steps 5, 6, 3, 7, 8, Repeat 9, 6, 3, 4 The crane work mode can be maintained by switching (returning) the manual selection switch 59 to the crane work mode while repeating steps 5, 6, 3, 7, 8, 9, 6, 3, and 4. it can. Thus, even if the manual selection switch 59 is mistakenly switched to the excavation work mode during the crane work of the hydraulic excavator 1, the excavator 1 is prevented from suddenly switching to the excavation work mode, and the crane work mode is maintained. can do. As a result, the stability of the excavator 1 during crane work can be maintained.

  Thus, according to the present embodiment, the controller 57 is configured to hold the crane work mode even when the hook sensor 45 is out of order when the crane work mode is being executed. Thereby, even if the hook sensor 45 is malfunctioning, the work mode is not switched suddenly, and the stability of the excavator 1 during crane work can be ensured. When the hook 26 is stored in the hook storage space 25 of the bucket link 15 and the excavation work mode is selected by the manual selection switch 59 (when the crane work mode is canceled), the controller 57 automatically By switching from the work mode to the excavation work mode, excavation work using the bucket 7 can be performed. Therefore, it is possible to avoid a situation in which the excavator 1 is in a resting state in the crane work mode and to perform excavation work using the bucket 7, so that the excavator 1 can be effectively used.

  Further, the controller 57 is configured to maintain the crane work mode when the hook 26 is in the take-out position even when the excavation work mode is selected by the manual selection switch 59. Thus, even when the operator accidentally switches the manual selection switch 59 to the excavation work mode while the hook 26 is in the take-out position, the excavator 1 can maintain the crane work state. As a result, by suspending the suspended load in the excavation work mode, it is possible to prevent the vehicle body of the hydraulic excavator 1 from becoming unstable, and the safety of work using the hydraulic excavator 1 can be improved.

  Furthermore, an operator (hanging worker) who hangs a suspended rope on the hook 26 can take the hook 26 out of the hook storage space 25 to automatically switch to the crane operation mode from the staking operator side. Accordingly, since the operator in the cab 3A can be quickly switched to the crane operation mode without notifying the operator of the cab 3A that the hook 26 has been taken out, the workability of the crane operation can be improved.

  Further, in the present embodiment, a manual selection switch 59 for manually switching between the excavation work mode and the crane work mode is provided, and the controller 57 uses the manual selection switch 59 to perform crane work even when the hook sensor 45 is malfunctioning. When the mode is selected, the crane operation mode is switched. As a result, even if the hook sensor 45 is malfunctioning, the crane operation or the excavation operation can be arbitrarily performed based on the operator's judgment by selecting the crane operation mode and the excavation operation mode with the manual selection switch 59. Can be executed.

  In the embodiment described above, the side plates 36B and 36C are provided facing each other at both side ends in the length direction of the connecting plates 21 and 22 of the bucket link 15 of the rising plate 36A constituting the other guide member 36. A configuration in which the sensor housing chamber 38 is surrounded by the side plates 36B, 36C and the rising plate 36A is illustrated. However, the present invention is not limited to this. For example, a side plate 36B may be provided at one side end of the rising plate 36A, and the sensor housing chamber may be surrounded by the rising plate 36A and the side plate 36B.

  In the above-described embodiment, the left and right cylinder-side bosses 16 and 17, the left and right bucket-side bosses 18 and 19, the left and right connecting plates 21 and 22, and the closing plate 23 are integrally formed by casting. The box-shaped bucket link 15 made is illustrated. However, the present invention is not limited to this. For example, the left and right cylinder side bosses, the left and right bucket side bosses, the left and right connecting plates, and the closing plate are formed as separate members, and these are welded. The present invention can also be applied to a bucket link formed in a box shape using means.

2 Lower traveling body (car body)
3 Upper swing body (car body)
4 Front device 5 Boom 6 Arm 7 Bucket 15 Bucket link 16 Left cylinder side boss (first connecting portion)
17 Right cylinder side boss (first connecting part)
18 Left bucket boss (second connecting part)
19 Right bucket side boss (second connecting part)
21 Left connecting plate (the other connecting plate)
22 right connecting plate 23 closing plate 24 opening 25 hook storage space 26 hook 31 hook holding mechanism 33 one guide member 36 other guide member 36A rising plate 36B, 36C side plate 36D long slot hole (passing hole)
38 Sensor housing chamber 39 Lock member 41 Detection plate support shaft (support shaft)
42 Detection plate (detection member)
45 Hook sensor 45A Male thread (Detection distance adjustment mechanism)
45B detector 45C nut (detection distance adjustment mechanism)
46 Sensor cover 57 Controller 59 Manual selection switch

Claims (6)

A self-propelled vehicle body and a front device provided on the vehicle body,
The front device includes a boom attached to the vehicle body so as to be able to move up and down, an arm rotatably attached to a tip end side of the boom, and an excavation attached to the tip end side of the arm and rotated by a bucket cylinder. A bucket for work, a bucket link connecting the bucket and the bucket cylinder and having a hook storage space formed therein, a hook for crane work provided in the bucket link, and the hook being the hook A hook sensor for detecting whether the storage position is stored in the storage space or the extraction position extracted from the hook storage space;
When the output of the hook sensor is in the retracted position, switching to an excavation work mode that allows excavation work using the bucket, and when the output of the hook sensor is in the take-out position, crane work using the hook Equipped with a controller that controls to switch to a crane work mode that allows
The bucket link includes a pair of connecting plates that are connected to each other between the first connecting portion on the bucket cylinder side and the second connecting portion on the bucket side, and one side of each connecting plate. Are formed in a box-like shape including a closing plate that closes between the end surfaces, and an opening provided between the other end surfaces of the connecting plates,
In the hook storage space of the bucket link, a pair of guide members provided on the closing plate of the bucket link to guide the hook to the storage position and sandwiching the hook from both sides, and the guide members In a hydraulic excavator having a crane function provided with a hook holding mechanism provided on one guide member and having a lock member that locks the hook in the retracted position,
The other guide member of the guide members, the other connection plate facing the other guide member of the connection plates, and the closing plate are used as external obstacles in the hook storage space. A sensor storage chamber that is a protected space is formed,
The sensor accommodating chamber is provided with a detection unit of the hook sensor in a state of being isolated from the hook, and is displaced by the hook when the hook is stored in the storage position, and the displacement is detected by the hook sensor. A detection member is provided ,
The hook sensor is provided on the other guide member in a state where the detection portion of the hook sensor faces the detection member,
A hydraulic excavator having a crane function, wherein the hook sensor is provided with a detection distance adjustment mechanism for adjusting a distance when detecting the detection member . The other guide member includes a rising plate rising from the closing plate of the bucket link toward the opening, a side plate provided on at least one side end surface of the rising plate, and the side plate provided on the side plate. A support shaft extending in the length direction of each connecting plate and rotatably supporting the detection member, and the detection member is provided when the detection member is provided on the rising plate and rotates about the support shaft. And including a through hole to be
The detection member is detected by the hook sensor in the sensor housing chamber when pressed by the hook stored in the storage position, and the passage hole when the hook is detached from the storage position. The hydraulic excavator provided with the crane function according to claim 1, wherein the excavator is configured to be displaced between a non-detection position protruding outside the sensor storage chamber and out of a detection range by the hook sensor.   The hydraulic excavator having a crane function according to claim 1, wherein the other guide member is provided with a sensor cover that covers a portion of the hook sensor that protrudes from the sensor housing chamber.   2. The hydraulic excavator having a crane function according to claim 1, wherein the controller automatically switches to the excavation work mode when the hook sensor is malfunctioning. 3.   The hook sensor outputs an ON signal when the hook is in the take-out position, and when the hook is in the retracted position, the OFF signal is the same as when the hook sensor is malfunctioning or broken. The hydraulic excavator having a crane function according to claim 1, wherein the controller is configured to switch to the excavation work mode when the hook sensor outputs an OFF signal. A manual selection switch for manually switching between the excavation work mode and the crane work mode is provided,
2. The crane function according to claim 1, wherein the controller is configured to switch to the crane work mode when the crane work mode is selected by the manual selection switch even when the hook sensor is malfunctioning. Hydraulic excavator.

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